1,187 research outputs found

    Real-time PCR reveals a high incidence of Symbiodinium clade D at low levels in four scleractinian corals across the Great Barrier Reef:Implications for symbiont shuffling

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    Reef corals form associations with an array of genetically and physiologically distinct endosymbionts from the genus Symbiodinium. Some corals harbor different clades of symbionts simultaneously, and over time the relative abundances of these clades may change through a process called symbiont shuffling. It is hypothesized that this process provides a mechanism for corals to respond to environmental threats such as global warming. However, only a minority of coral species have been found to harbor more than one symbiont clade simultaneously and the current view is that the potential for symbiont shuffling is limited. Using a newly developed real-time PCR assay, this paper demonstrates that previous studies have underestimated the presence of background symbionts because of the low sensitivity of the techniques used. The assay used here targets the multi-copy rDNA ITS1 region and is able to detect Symbiodinium clades C and D with > 100-fold higher sensitivity compared to conventional techniques. Technical considerations relating to intragenomic variation, estimating copy number and non-symbiotic contamination are discussed. Eighty-two colonies from four common scleractinian species (Acropora millepora, Acropora tenuis, Stylophora pistillata and Turbinaria reniformis) and 11 locations on the Great Barrier Reef were tested for background Symbiodinium clades. Although these colonies had been previously identified as harboring only a single clade based on SSCP analyses, background clades were detected in 78% of the samples, indicating that the potential for symbiont shuffling may be much larger than currently thought

    Does the Clinical Frailty Scale at Triage Predict Outcomes From Emergency Care for Older People?

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    Study objective: We determine whether the Clinical Frailty Scale applied at emergency department (ED) triage is associated with important service- and patient-related outcomes. Methods: We undertook a single-center, retrospective cohort study examining hospital-related outcomes and their associations with frailty scores assessed at ED triage. Participants were aged 65 years or older, registered on their first ED presentation during the study period at a single, centralized ED in the United Kingdom. Baseline data included age, sex, Clinical Frailty Scale score, National Early Warning Score–2 and the Charlson Comorbidity Index score; outcomes included length of stay, readmissions (any future admissions), and mortality (inhospital or out of hospital) up to 2 years after ED presentation. Survival analysis methods (standard and competing risks) were applied to assess associations between ED triage frailty scores and outcomes. Unadjusted incidence curves and adjusted hazard ratios are presented. Results: A total of 52,562 individuals representing 138,328 ED attendances were included; participants’ mean age was 78.0 years, and 55% were women. Initial admission rates generally increased with frailty. Mean length of stay after 30- or 180-day follow-up was relatively low; all Clinical Frailty Scale categories included patients who experienced zero days’ length of stay (ie, ambulatory care) and patients with relatively high numbers of inhospital days. Overall, 46% of study participants were readmitted by the 2-year follow-up. Readmissions increased with Clinical Frailty Scale score up until a score of 6 and then attenuated. Mortality rates increased with increasing frailty; the adjusted hazard ratio was 3.6 for Clinical Frailty Scale score 7 to 8 compared with score 1 to 3. Conclusion: Frailty assessed at ED triage (with the Clinical Frailty Scale) is associated with adverse outcomes in older people. Its use in ED triage might aid immediate clinical decisionmaking and service configuration

    The effect of relative hypotension on 30-day mortality in older people receiving emergency care

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    Research has observed increased mortality among older people attending the emergency department (ED) who had systolic pressure > 7 mmHg lower than baseline primary care values. This study aimed to (1) assess feasibility of identifying this ‘relative hypotension’ using readily available ED data, (2) externally validate the 7 mmHg threshold, and (3) refine a threshold for clinically important relative hypotension. A single-centre retrospective cohort study linked year 2019 data for ED attendances by people aged over 64 to hospital discharge vital signs within the previous 18 months. Frailty and comorbidity scores were calculated. Previous discharge (‘baseline’) vital signs were subtracted from initial ED values to give individuals’ relative change. Cox regression analysis compared relative hypotension > 7 mmHg with mean time to mortality censored at 30 days. The relative hypotension threshold was refined using a fully adjusted risk tool formed of logistic regression models. Receiver operating characteristics were compared to NEWS2 models with and without incorporation of relative systolic. 5136 (16%) of 32,548 ED attendances were linkable with recent discharge vital signs. Relative hypotension > 7 mmHg was associated with increased 30-day mortality (HR 1.98; 95% CI 1.66–2.35). The adjusted risk tool (AUC: 0.69; sensitivity: 0.61; specificity: 0.68) estimated each 1 mmHg relative hypotension to increase 30-day mortality by 2% (OR 1.02; 95% CI 1.02–1.02). 30-day mortality prediction was marginally better with NEWS2 (AUC: 0.73; sensitivity: 0.59; specificity: 0.78) and NEWS2 + relative systolic (AUC: 0.74; sensitivity: 0.63; specificity: 0.75). Comparison of ED vital signs with recent discharge observations was feasible for 16% individuals. The association of relative hypotension > 7 mmHg with 30-day mortality was externally validated. Indeed, any relative hypotension appeared to increase risk, but model characteristics were poor. These findings are limited to the context of older people with recent hospital admissions

    Contracting outsourced services with collaborative key performance indicatiors

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    While service outsourcing may benefit from the application of performance‐based contracts (PBCs), the implementation of such contracts is usually challenging. Service performance is often not only dependent on supplier effort but also on the behavior of the buying firm. Existing research on performance‐based contracting provides very limited understanding on how this challenge may be overcome. This article describes a design science research project that develops a novel approach to buyer–supplier contracting, using collaborative key performance indicators (KPIs). Collaborative KPIs evaluate and reward not only the supplier contribution to customer performance but also the customer's behavior to enable this. In this way, performance‐based contracting can also be applied to settings where supplier and customer activities are interdependent, while traditional contracting theories suggest that output controls are not effective under such conditions. In the collaborative KPI contracting process, indicators measure both supplier and customer (buying firm) performance and promote collaboration by being defined through a collaborative process and by focusing on end‐of‐process indicators. The article discusses the original case setting of a telecommunication service provider experiencing critical problems in outsourcing IT services. The initial intervention implementing this contracting approach produced substantial improvements, both in performance and in the relationship between buyer and supplier. Subsequently, the approach was tested and evaluated in two other settings, resulting in a set of actionable propositions on the efficacy of collaborative KPI contracting. Our study demonstrates how defining, monitoring, and incentivizing the performance of specific processes at the buying firm can help alleviate the limitations of traditional performance‐based contracting when the supplier's liability for service performance is difficult to verify

    Coulomb-assisted braiding of Majorana fermions in a Josephson junction array

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    We show how to exchange (braid) Majorana fermions in a network of superconducting nanowires by control over Coulomb interactions rather than tunneling. Even though Majorana fermions are charge-neutral quasiparticles (equal to their own antiparticle), they have an effective long-range interaction through the even-odd electron number dependence of the superconducting ground state. The flux through a split Josephson junction controls this interaction via the ratio of Josephson and charging energies, with exponential sensitivity. By switching the interaction on and off in neighboring segments of a Josephson junction array, the non-Abelian braiding statistics can be realized without the need to control tunnel couplings by gate electrodes. This is a solution to the problem how to operate on topological qubits when gate voltages are screened by the superconductor

    A community change in the algal endosymbionts of a scleractinian coral following a natural bleaching event: field evidence of acclimatization.

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    The symbiosis between reef-building corals and their algal endosymbionts (zooxanthellae of the genus Symbiodinium) is highly sensitive to temperature stress, which makes coral reefs vulnerable to climate change. Thermal tolerance in corals is known to be substantially linked to the type of zooxanthellae they harbour and, when multiple types are present, the relative abundance of types can be experimentally manipulated to increase the thermal limits of individual corals. Although the potential exists for this to translate into substantial thermal acclimatization of coral communities, to date there is no evidence to show that this takes place under natural conditions. In this study, we show field evidence of a dramatic change in the symbiont community of Acropora millepora, a common and widespread Indo-Pacific hard coral species, after a natural bleaching event in early 2006 in the Keppel Islands (Great Barrier Reef ). Before bleaching, 93.5% (nZ460) of the randomly sampled and tagged colonies predominantly harboured the thermally sensitive Symbiodinium type C2, while the remainder harboured a tolerant Symbiodinium type belonging to clade D or mixtures of C2 and D. After bleaching, 71% of the surviving tagged colonies that were initially C2 predominant changed to D or C1 predominance. Colonies that were originally C2 predominant suffered high mortality (37%) compared with D-predominant colonies (8%). We estimate that just over 18% of the original A. millepora population survived unchanged leaving 29% of the population C2 and 71% D or C1 predominant six months after the bleaching event. This change in the symbiont community structure, while it persists, is likely to have substantially increased the thermal tolerance of this coral population. Understanding the processes that underpin the temporal changes in symbiont communities is key to assessing the acclimatization potential of reef corals

    The impact of COVID-19-pandemic-related adversity on mental health:longitudinal study in Dutch populations with and without mental health disorders

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    BACKGROUND: Despite growing concerns about mental health during the COVID-19 pandemic, particularly in people with pre-existing mental health disorders, research has shown that symptoms of depression and anxiety were generally quite stable, with modest changes in certain subgroups. However, individual differences in cumulative exposure to COVID-19 stressors have not been yet considered.AIMS: We aimed to quantify and investigate the impact of individual-level cumulative exposure to COVID-19-pandemic-related adversity on changes in depressive and anxiety symptoms and loneliness. In addition, we examined whether the impact differed among individuals with various levels of pre-pandemic chronicity of mental health disorders.METHOD: Between April 2020 and July 2021, 15 successive online questionnaires were distributed among three psychiatric case-control cohorts that started in the 2000s ( N = 1377). Outcomes included depressive and anxiety symptoms and loneliness. We developed a COVID-19 Adversity Index (CAI) summarising up to 15 repeated measures of COVID-19-pandemic-related exposures (e.g. exposure to COVID-19 infection, negative economic impact and quarantine). We used linear mixed linear models to estimate the effects of COVID-19-related adversity on mental health and its interaction with pre-pandemic chronicity of mental health disorders and CAI. RESULTS: Higher CAI scores were positively associated with higher increases in depressive symptoms, anxiety symptoms and loneliness. Associations were not statistically significantly different between groups with and without (chronic) pre-pandemic mental health disorders.CONCLUSIONS: Individual differences in cumulative exposure to COVID-19-pandemic-related adversity are important predictors of mental health, but we found no evidence for higher vulnerability among people with (chronic) pre-pandemic mental health disorders.</p

    The mental health impact of the COVID-19 pandemic on people with and without depressive, anxiety, or obsessive-compulsive disorders:a longitudinal study of three Dutch case-control cohorts

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    Background: The impact of the COVID-19 pandemic on mental health in people with pre-existing mental health disorders is unclear. In three psychiatry case-control cohorts, we compared the perceived mental health impact and coping and changes in depressive symptoms, anxiety, worry, and loneliness before and during the COVID-19 pandemic between people with and without lifetime depressive, anxiety, or obsessive-compulsive disorders. Methods: Between April 1 and May 13, 2020, online questionnaires were distributed among the Netherlands Study of Depression and Anxiety, Netherlands Study of Depression in Older Persons, and Netherlands Obsessive Compulsive Disorder Association cohorts, including people with (n=1181) and without (n=336) depressive, anxiety, or obsessive-compulsive disorders. The questionnaire contained questions on perceived mental health impact, fear of COVID-19, coping, and four validated scales assessing depressive symptoms, anxiety, worry, and loneliness used in previous waves during 2006–16. Number and chronicity of disorders were based on diagnoses in previous waves. Linear regression and mixed models were done. Findings: The number and chronicity of disorders showed a positive graded dose–response relation, with greater perceived impact on mental health, fear, and poorer coping. Although people with depressive, anxiety, or obsessive-compulsive disorders scored higher on all four symptom scales than did individuals without these mental health disorders, both before and during the COVID-19 pandemic, they did not report a greater increase in symptoms during the pandemic. In fact, people without depressive, anxiety, or obsessive-compulsive disorders showed a greater increase in symptoms during the COVID-19 pandemic, whereas individuals with the greatest burden on their mental health tended to show a slight symptom decrease. Interpretation: People with depressive, anxiety, or obsessive-compulsive disorders are experiencing a detrimental impact on their mental health from the COVID-19 pandemic, which requires close monitoring in clinical practice. Yet, the COVID-19 pandemic does not seem to have further increased symptom severity compared with their prepandemic levels. Funding: Dutch Research Council
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