Water-like anomalies for core-softened models of fluids: One dimension

We use a one-dimensional (1d) core-softened potential to develop a physical picture for some of the anomalies present in liquid water. The core-softened potential mimics the effect of hydrogen bonding. The interest in the 1d system stems from the facts that closed-form results are possible and that the qualitative behavior in 1d is reproduced in the liquid phase for higher dimensions. We discuss the relation between the shape of the potential and the density anomaly, and we study the entropy anomaly resulting from the density anomaly. We find that certain forms of the two-step square well potential lead to the existence at T=0 of a low-density phase favored at low pressures and of a high-density phase favored at high pressures, and to the appearance of a point $C'$ at a positive pressure, which is the analog of the T=0 ``critical point'' in the $1d$ Ising model. The existence of point $C'$ leads to anomalous behavior of the isothermal compressibility $K_T$ and the isobaric specific heat $C_P$.Comment: 22 pages, 7 figure

Accuracy Assessment of the ESA CCI 20M Land Cover Map: Kenya, Gabon, Ivory Coast and South Africa

This working paper presents the overall and spatial accuracy assessment of the European Space Agency (ESA) 20 m prototype land cover map for Africa for four countries: Kenya, Gabon, Ivory Coast and South Africa. This accuracy assessment was undertaken as part of the ESA-funded CrowdVal project. The results varied from 44% (for South Africa) to 91% (for Gabon). In the case of Kenya (56% overall accuracy) and South Africa, these values are largely caused by the confusion between grassland and shrubland. However, if a weighted confusion matrix is used, which diminishes the importance of the confusion between grassland and shrubs, the overall accuracy for Kenya increases to 79% and for South Africa, 75%. The overall accuracy for Ivory Coast (47%) is a result of a highly fragmented land cover, which makes it a difficult country to map with remote sensing. The exception was Gabon with a high overall accuracy of 91%, but this can be explained by the high amount of tree cover across the country, which is a relatively easy class to map

Factors Associated with Revision Surgery after Internal Fixation of Hip Fractures

Background: Femoral neck fractures are associated with high rates of revision surgery after management with internal fixation. Using data from the Fixation using Alternative Implants for the Treatment of Hip fractures (FAITH) trial evaluating methods of internal fixation in patients with femoral neck fractures, we investigated associations between baseline and surgical factors and the need for revision surgery to promote healing, relieve pain, treat infection or improve function over 24 months postsurgery. Additionally, we investigated factors associated with (1) hardware removal and (2) implant exchange from cancellous screws (CS) or sliding hip screw (SHS) to total hip arthroplasty, hemiarthroplasty, or another internal fixation device. Methods: We identified 15 potential factors a priori that may be associated with revision surgery, 7 with hardware removal, and 14 with implant exchange. We used multivariable Cox proportional hazards analyses in our investigation. Results: Factors associated with increased risk of revision surgery included: female sex, [hazard ratio (HR) 1.79, 95% confidence interval (CI) 1.25-2.50; P = 0.001], higher body mass index (fo

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Platelet phosphatidylserine exposure and procoagulant activity in clotting whole blood : different effects of collagen,TRAP and calcium ionophore A23187

We have studied the effects of different platelet agonists onphosphatidylserine (PS) exposure and clotting times in bloodwithout anticoagulants. Similar reductions in clotting time wereobtained for collagen, TRAP-6 or calcium ionophore A23187(50 µmol/L), in spite of huge differences in PS expression[6.7 ± 2.4%, 2.3 ± 0.5% and 99.9 ± 0.1%, respectively (mean ±SD, n = 5)]. Furthermore, the clotting times were much longerfor samples with A23187 exposing the same amounts of PS assamples with collagen or TRAP-6. Annexin V reversed theclotting time reduction, but could not prevent coagulation.Addition of phospholipid vesicles containing 20% PS neitheraffected the clotting times nor induced clotting in recalcified,platelet-free plasma.We conclude that platelet PS exposure is necessary, but notsufficient, for the coagulation amplification observed whenplatelets are stimulated via physiological receptors in a wholeblood environment

The High-Dose Aldesleukin “Select” Trial: A Trial to Prospectively Validate Predictive Models of Response to Treatment in Patients with Metastatic Renal Cell Carcinoma

PURPOSE: High-dose aldesleukin (HD IL-2) received FDA approval for the treatment of mRCC in 1992, producing a 14% objective response rate (ORR) and durable remissions. Retrospective studies suggested that clinical and pathologic features could predict for benefit. The Cytokine Working Group conducted this prospective trial to validate proposed predictive markers of response to HD IL-2. EXPERIMENTAL DESIGN: Standard HD IL-2 was administered to prospectively evaluate whether the ORR of mRCC patients with “good” predictive pathologic features based on an “integrated selection” model (ISM) (e.g. clear-cell histology sub-classification and carbonic anhydrase-9 (CA-9) IHC staining) was significantly higher than the ORR of a historical, unselected population. Archived tumor was collected for pathologic analysis including tumor programmed death-ligand 1 (PD-L1) expression. RESULTS: 120 eligible patients enrolled between 11/06 and 7/09; 70% were MSKCC intermediate risk, 96% had clear cell RCC and 99% had prior nephrectomy. The independently assessed ORR was 25% (30/120, 95% CI = 17.5%–33.7%, p=0.0014) (3 CR, 27 PR) and was higher than a historical ORR. Thirteen patients (11%) remained progression-free at 3 years and the median OS was 42.8 months. ORR was not statistically different by ISM classification (“good-risk” 23% vs. “poor-risk” 30%, (p=0.39)). ORR was positively associated with tumor PD-L1 expression (p=0.01) by IHC. CONCLUSIONS: In this prospective, biomarker validation study, HD IL-2 produced durable remissions and prolonged survival in both “good” and “poor-risk” patients. The proposed ISM was unable to improve the selection criteria. Novel markers (e.g. tumor PD-L1expression) appeared useful, but require independent validation

Singapore 1994-1996: Bibliographies

10.1177/002200949803300306The Journal of Commonwealth Literature333134-15