Absolute quantum energy inequalities in curved spacetime

Quantum Energy Inequalities (QEIs) are results which limit the extent to which the smeared renormalised energy density of the quantum field can be negative, when averaged along a timelike curve or over a more general timelike submanifold in spacetime. On globally hyperbolic spacetimes the minimally-coupled massive quantum Klein--Gordon field is known to obey a `difference' QEI that depends on a reference state chosen arbitrarily from the class of Hadamard states. In many spacetimes of interest this bound cannot be evaluated explicitly. In this paper we obtain the first `absolute' QEI for the minimally-coupled massive quantum Klein--Gordon field on four dimensional globally hyperbolic spacetimes; that is, a bound which depends only on the local geometry. The argument is an adaptation of that used to prove the difference QEI and utilises the Sobolev wave-front set to give a complete characterisation of the singularities of the Hadamard series. Moreover, the bound is explicit and can be formulated covariantly under additional (general) conditions. We also generalise our results to incorporate adiabatic states.Comment: 31 pages. Corrections and clarifications added. Final version to appear in Ann. H. Poincar

What do near-term observations tell us about long-term developments in greenhouse gas emissions? A letter

Long-term scenarios developed by integrated assessment models are used in climate research to provide an indication of plausible long-term emissions of greenhouse gases and other radiatively active substances based on developments in the global energy system, land-use and the emissions associated with these systems The phenomena that determine these long-term developments (several decades or even centuries) are very different than those that operate on a shorter time-scales (a few years) Nevertheless, in the literature, we still often find direct comparisons between short-term observations and long-term developments that do not take into account the differing dynamics over these time scales In this letter, we discuss some of the differences between the factors that operate in the short term and those that operate in the long term We use long-term historical emissions trends to show that short-term observations are very poor indicators of long-term future emissions developments Based on this, we conclude that the performance of long-term scenarios should be evaluated against the appropriate, corresponding long-term variables and trends The research community may facilitate this by developing appropriate data sets and protocols that can be used to test the performance of long-term scenarios and the models that produce the

Benefits of greenhouse gas mitigation on the supply, management, and use of water resources in the United States

Climate change impacts on water resources in the United States are likely to be far-reaching and substantial because the water is integral to climate, and the water sector spans many parts of the economy. This paper estimates impacts and damages from five water resource-related models addressing runoff, drought risk, economics of water supply/demand, water stress, and flooding damages. The models differ in the water system assessed, spatial scale, and unit of assessment, but together provide a quantitative and descriptive richness in characterizing water sector effects that no single model can capture. The results, driven by a consistent set of greenhouse gas (GHG) emission and climate scenarios, examine uncertainty from emissions, climate sensitivity, and climate model selection. While calculating the net impact of climate change on the water sector as a whole may be impractical, broad conclusions can be drawn regarding patterns of change and benefits of GHG mitigation. Four key findings emerge: 1) GHG mitigation substantially reduces hydro-climatic impacts on the water sector; 2) GHG mitigation provides substantial national economic benefits in water resources related sectors; 3) the models show a strong signal of wetting for the Eastern US and a strong signal of drying in the Southwest; and 4) unmanaged hydrologic systems impacts show strong correlation with the change in magnitude and direction of precipitation and temperature from climate models, but managed water resource systems and regional economic systems show lower correlation with changes in climate variables due to non-linearities created by water infrastructure and the socio-economic changes in non-climate driven water demand

A Computer Simulation of Progesterone and Cox2 Inhibitor Treatment for Preterm Labor

Background: Sufficient information from in vitro and in vivo studies has become available to permit computer modeling of the processes that occur in the myometrium during labor. This development allows the in silico investigation of pathological mechanisms and the trialing of potential treatments. Methods/Results: Based on the human literature, we developed a computer model of the immune-endocrine environment of the myometrial cell. The interactions between molecules are represented by differential equations. The model is designed to simulate the estrogen and progesterone receptor changes during pregnancy and particularly the changes in the progesterone receptor (PR) isoforms A and B that are thought to mediate functional progesterone withdrawal in the human at labor. Parturition is represented by an increase in the PRA to PRB ratio to levels seen in women in labor. Infection is shown by inducing inflammation in the system by increasing phospho-IkB kinase concentration (IKK) levels; which lead to increased NF-kappa B activation, causing an increase in the PRA/PRB ratio. We examined the effects of progesterone or cyclooxygenase 2 (Cox2) inhibitor treatments on the PRA/PRB ratio in silico. The model predicted that high doses of progesterone and Cox2 inhibition would be effective in preventing an NF-kappa B-induced PRA/PRB ratio increase to the levels found during labor. Conclusions: Our data illustrate the use of dynamic biological computer simulations to test the effectiveness of therapeutic interventions. This may allow the early rejection of ineffective therapies prior to expensive field trials

An absolute quantum energy inequality for the Dirac field in curved spacetime

Quantum Weak Energy Inequalities (QWEIs) are results which limit the extent to which the smeared renormalised energy density of a quantum field can be negative. On globally hyperbolic spacetimes the massive quantum Dirac field is known to obey a QWEI in terms of a reference state chosen arbitrarily from the class of Hadamard states; however, there exist spacetimes of interest on which state-dependent bounds cannot be evaluated. In this paper we prove the first QWEI for the massive quantum Dirac field on four dimensional globally hyperbolic spacetime in which the bound depends only on the local geometry; such a QWEI is known as an absolute QWEI

Antibiotic Class and Outcome in Post-stroke Infections: An Individual Participant Data Pooled Analysis of VISTA-Acute

Antibiotics; Post-stroke infections; Post-stroke pneumoniaAntibiòtics; Infeccions posteriors a un accident cerebrovascular; Pneumònia posterior a un accident cerebrovascularAntibióticos; Infecciones posteriores a un accidente cerebrovascular; Neumonía posterior a un accidente cerebrovascularIntroduction: Antibiotics used to treat post-stroke infections have differing antimicrobial and anti-inflammatory effects. Our aim was to investigate whether antibiotic class was associated with outcome after post-stroke infection. Methods: We analyzed pooled individual participant data from the Virtual International Stroke Trials Archive (VISTA)-Acute. Patients with ischemic stroke and with an infection treated with systemic antibiotic therapy during the first 2 weeks after stroke onset were eligible. Antibiotics were grouped into eight classes, according to antimicrobial mechanism and prevalence. The primary analysis investigated whether antibiotic class for any infection, or for pneumonia, was independently associated with a shift in 90 day modified Rankin Scale (mRS) using ordinal logistic regression. Results: 2,708 patients were eligible (median age [IQR] = 74 [65 to 80] y; 51% female; median [IQR] NIHSS score = 15 [11 to 19]). Pneumonia occurred in 35%. Treatment with macrolides (5% of any infections; 9% of pneumonias) was independently associated with more favorable mRS distribution for any infection [OR (95% CI) = 0.59 (0.42 to 0.83), p = 0.004] and for pneumonia [OR (95% CI) = 0.46 (0.29 to 0.73), p = 0.001]. Unfavorable mRS distribution was independently associated with treatment of any infection either with carbapenems, cephalosporins or monobactams [OR (95% CI) = 1.62 (1.33 to 1.97), p < 0.001], penicillin plus β-lactamase inhibitors [OR (95% CI) = 1.26 (1.03 to 1.54), p = 0.025] or with aminoglycosides [OR (95% CI) = 1.73 (1.22 to 2.46), p = 0.002]. Conclusion: This retrospective study has several limitations including effect modification and confounding by indication. Macrolides may have favorable immune-modulatory effects in stroke-associated infections. Prospective evaluation of the impact of antibiotic class on treatment of post-stroke infections is warranted.The Open Access Publication Fund of Charité—Universitätsmedizin Berlin and Professor Meisel as corresponding author will provide funding to cover the open access publication/article processing fe

Predictors of mortality and disability in stroke-associated pneumonia

Whilst stroke-associated pneumonia (SAP) is common and associated with poor outcomes, less is known about the determinants of these adverse clinical outcomes in SAP. To identify the factors that influence mortality and morbidity in SAP. Data for patients with SAP (n = 854) were extracted from a regional Hospital Stroke Register in Norfolk, UK (2003-2015). SAP was defined as pneumonia occurring within 7 days of admission by the treating clinicians. Mutlivariable regression models were constructed to assess factors influencing survival and the level of disability at discharge using modified Rankin Scale [mRS]. Mean (SD) age was 83.0 (8.7) years and ischaemic stroke occurred in 727 (85.0%). Mortality was 19.0% at 30 days and 44.0% at 6 months. Stroke severity assessment using National Institutes of Health Stroke Scale was not recorded in the data set although Oxfordshire Community Stroke Project was Classification. In the multivariable analyses, 30-day mortality was independently associated with age (OR 1.04, 95% CI 1.01-1.07, p = 0.01), haemorrhagic stroke (2.27, 1.07-4.78, p = 0.03) and pre-stroke disability (mRS 4-5 v 0-1: 6.45, 3.12-13.35, p < 0.001). 6-month mortality was independently associated with age (< 0.001), pre-stroke disability (p < 0.001) and certain comorbidities, including the following: dementia (6.53, 4.73-9.03, p < 0.001), lung cancer (2.07, 1.14-3.77, p = 0.017) and previous transient ischemic attack (1.94, 1.12-3.36, p = 0.019). Disability defined by mRS at discharge was independently associated with age (1.10, 1.05-1.16, p < 0.001) and plasma C-reactive protein (1.02, 1.01-1.03, p = 0.012). We have identified non-modifiable determinants of poor prognosis in patients with SAP. Further studies are required to identify modifiable factors which may guide areas for intervention to improve the prognosis in SAP in these patients

Common Genetic Variants Explain the Majority of the Correlation Between Height and Intelligence : The Generation Scotland Study

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Time Course Change of Muscle Thickness of the Tibialis Anterior Following Blood Flow Restricted Training

Traditional resistance training programs recommend training loads of at least 60% 1-repetition maximum (1RM) to stimulate muscle hypertrophy within 3 weeks. Low-load blood flow restricted (BFR) resistance training (RT) has implications in rehabilitation since this modality has shown comparable muscle hypertrophy to high-load RT at intensities as low as 30% 1RM. However, the recommended effects of BFR on muscle size in various musculature throughout an intervention has not been thoroughly examined. PURPOSE: Therefore, the purpose of this investigation is to measure temporal changes in muscle thickness (MT) on the tibialis anterior (TA) throughout 4 weeks of BFR training. METHODS: Thirteen untrained participants were randomized into two groups: (BFR; n=8) (177.6 ± 4.1 cm, 84.8 ± 15.1 kg, 21.3 ± 1 years) or control non-BFR (n=5) (172.6 ± 8.2 cm, 76.7 ± 11.1 kg, 23.4 ± 2.7 years) who were matched for training sessions, sets, and reps. During the 4-week period (8 sessions), participants underwent twice-weekly sessions of unilateral isokinetic dorsiflexion training at 30% of their daily peak torque at a velocity of 60°/s with or without BFR. Ultrasound-derived measures of muscle thickness were captured at one-third the distance from the fibular head to the medial malleolus prior to the pre- and post-intervention testing sessions. Two separate linear regression analyses were used to examine group slope differences in MT across all training sessions. RESULTS: Linear regression analyses indicated that the control (i.e., non-BFR) exhibited a significant, positive (b = 0.023, SE = 0.01, r2=0.626, p=0.006) increase in MT from pre- to post testing. However, there was no significant change (b=0.021, SE = 0.01, r2=0.324, p=0.086) in MT across Time for the BFR group. CONCLUSION: Low-load RT without BFR induces temporal changes in muscle size following a short 4-week intervention. This exemplifies the efficacy of low-load training in inducing detectible changes in muscle thickness of the TA, and does not indicate BFR has an additive effect on temporal changes in muscle size of novice males following a 4-week intervention