Algebraic Principles for Rely-Guarantee Style Concurrency Verification Tools

We provide simple equational principles for deriving rely-guarantee-style inference rules and refinement laws based on idempotent semirings. We link the algebraic layer with concrete models of programs based on languages and execution traces. We have implemented the approach in Isabelle/HOL as a lightweight concurrency verification tool that supports reasoning about the control and data flow of concurrent programs with shared variables at different levels of abstraction. This is illustrated on two simple verification examples

Predicting urinary creatinine excretion and its usefulness to identify incomplete 24h urine collections

Studies using 24 h urine collections need to incorporate ways to validate the completeness of the urine samples. Models to predict urinary creatinine excretion (UCE) have been developed for this purpose; however, information on their usefulness to identify incomplete urine collections is limited. We aimed to develop a model for predicting UCE and to assess the performance of a creatinine index using para-aminobenzoic acid (PABA) as a reference. Data were taken from the European Food Consumption Validation study comprising two non-consecutive 24 h urine collections from 600 subjects in five European countries. Data from one collection were used to build a multiple linear regression model to predict UCE, and data from the other collection were used for performance testing of a creatinine index-based strategy to identify incomplete collections. Multiple linear regression (n 458) of UCE showed a significant positive association for body weight (ß = 0·07), the interaction term sex × weight (ß = 0·09, reference women) and protein intake (ß = 0·02). A significant negative association was found for age (ß = - 0·09) and sex (ß = - 3·14, reference women). An index of observed-to-predicted creatinine resulted in a sensitivity to identify incomplete collections of 0·06 (95 % CI 0·01, 0·20) and 0·11 (95 % CI 0·03, 0·22) in men and women, respectively. Specificity was 0·97 (95 % CI 0·97, 0·98) in men and 0·98 (95 % CI 0·98, 0·99) in women. The present study shows that UCE can be predicted from weight, age and sex. However, the results revealed that a creatinine index based on these predictions is not sufficiently sensitive to exclude incomplete 24 h urine collections

Effects of Sodium-Glucose Co-transporter 2 Inhibition with Empaglifozin on Renal Structure and Function in Non-diabetic Rats with Left Ventricular Dysfunction After Myocardial Infarction

BACKGROUND: The use of sodium-glucose co-transporter 2 inhibitors (SGLT2i) is currently expanding to cardiovascular risk reduction in non-diabetic subjects, but renal (side-)effects are less well studied in this setting. METHODS: Male non-diabetic Sprague Dawley rats underwent permanent coronary artery ligation to induce MI, or sham surgery. Rats received chow containing empagliflozin (EMPA) (30 mg/kg/day) or control chow. Renal function and electrolyte balance were measured in metabolic cages. Histological and molecular markers of kidney injury, parameters of phosphate homeostasis and bone resorption were also assessed. RESULTS: EMPA resulted in a twofold increase in diuresis, without evidence for plasma volume contraction or impediments in renal function in both sham and MI animals. EMPA increased plasma magnesium levels, while the levels of glucose and other major electrolytes were comparable among the groups. Urinary protein excretion was similar in all treatment groups and no histomorphological alterations were identified in the kidney. Accordingly, molecular markers for cellular injury, fibrosis, inflammation and oxidative stress in renal tissue were comparable between groups. EMPA resulted in a slight increase in circulating phosphate and PTH levels without activating FGF23-Klotho axis in the kidney and bone mineral resorption, measured with CTX-1, was not increased. CONCLUSIONS: EMPA exerts profound diuretic effects without compromising renal structure and function or causing significant electrolyte imbalance in a non-diabetic setting. The slight increase in circulating phosphate and PTH after EMPA treatment was not associated with evidence for increased bone mineral resorption suggesting that EMPA does not affect bone health

Involving the patient: A prospective study on use, appreciation and effectiveness of an information system in head and neck cancer care

Objective: To determine use, appreciation and effectiveness of an electronic health information support system in head and neck (H&N) cancer care. Design: A prospective evaluation study. The evaluated system has four different functions: (1) communication amongst health care providers and between health care providers and patients, (2) information for health care providers and patients, (3) contact with fellow sufferers and (4) monitoring of discharged patients by means of electronic questionnaires. Evaluation of the system was done both objectively using automatically created log files and stored messages, and subjectively by using paper questionnaires from patients and general practitioners (GPs). Setting: Department of Otorhinolaryngology and Head and Neck Surgery of a tertiary health care centre in the Netherlands. The system was put at patients' disposal for a period of 6 weeks following discharge from the hospital after surgery for H&N cancer, and was additional to standard care. Participants: Head and neck cancer patients, hospital physicians, members of a hospital-based support team, GPs, district nurses and speech therapists. Main outcome measures: Actual use of the system by patients and health care providers. Patients' appreciation for each of the system's four different functions. GPs' appreciation for the system. Capability to detect potential patient problems with the system. Results: The system was used by 36 H&N cancer patients, 10 hospital physicians, 2 members of the support team, 8 GPs, 2 district nurses and 2 speech therapists. The total number of patient-sessions was 982: an average of 27.3 sessions per patient during the 6 weeks study period. In total, 456 monitoring questionnaires were completed. The support team in hospital responded with 231 actions. In 16 cases, an extra appointment was made for a patient with the hospital physician. Out of these cases, immediate action was considered necessary eight times. Patients appreciated the system highly, rating it with an average score of 8.0 on a 10-point scale. All patients used the monitoring function, and rated 'monitoring' with a mean score of 8.0 on a 10-point scale. Least used and appreciated was the 'contact with fellow sufferers' function. Only 8 out of possible 36 GPs used the system, rating it with an average of 5.6 on a 10-point scale. Conclusions: The electronic health information support system was used intensively and highly appreciated by H&N cancer patients. The system enabled the early detection of occurring health problems that required direct intervention. ICT can play an additional role in the management of patients, also in a relatively elderly and computer illiterate patient population

Atrial fibrillation detected at screening is not a benign condition:Outcomes in screen-detected versus clinically detected atrial fibrillation. Results from the Prevention of Renal and Vascular End-stage Disease (PREVEND) study

AIMS: It is unknown whether screen-detected atrial fibrillation (AF) carries cardiovascular risks similar to clinically detected AF. We aimed to compare clinical outcomes between individuals with screen-detected and clinically detected incident AF. METHODS: We studied 8265 participants (age 49 ± 13 years, 50% women) without prevalent AF from the community-based Prevention of Renal and Vascular End-stage Disease (PREVEND) study. By design of the PREVEND study, 70% of participants had a urinary albumin concentration >10 mg/L. Participants underwent 12-lead ECG screening at baseline and every 3 years. AF was considered screen-detected when first diagnosed during a study visit and clinically detected when first diagnosed during a hospital visit. We analysed data from the baseline visit (1997–1998) up to the third follow-up visit (2008). We used Cox regression with screen-detected and clinically detected AF as time-varying covariates to study the association of screen-detected and clinically detected AF with all-cause mortality, incident heart failure (HF) and vascular events. RESULTS: During a follow-up of 9.8 ± 2.3 years, 265 participants (3.2%) developed incident AF, of whom 60 (23%) had screen-detected AF. The majority of baseline characteristics were comparable between individuals with screen-detected and clinically detected AF. Unadjusted, both screen-detected and clinically detected AF were strongly associated with mortality, incident HF, and vascular events. After multivariable adjustment, screen-detected and clinically detected AF remained significantly associated with mortality (HR 2.21 (95% CI 1.09 to 4.47) vs 2.95 (2.18 to 4.00), p for difference=0.447) and incident HF (4.90 (2.28 to 10.57) vs 3.98 (2.49 to 6.34), p for difference=0.635). After adjustment, screen-detected AF was not significantly associated with vascular events, whereas clinically detected AF was (1.12 (0.46 to 2.71) vs 1.92 (1.21 to 3.06), p for difference=0.283). CONCLUSION: Screen-detected incident AF was associated with an increased risk of adverse outcomes, especially all-cause mortality and incident HF. The risk of outcomes was not significantly different between screen-detected AF and clinically detected AF

An Updated Description of Heavy-Hadron Interactions in Geant-4

Exotic stable massive particles (SMP) are proposed in a number of scenarios of physics beyond the Standard Model. It is important that LHC experiments are able both to detect and extract the quantum numbers of any SMP with masses around the TeV scale. To do this, an understanding of the interactions of SMPs in matter is required. In this paper a Regge-based model of R-hadron scattering is extended and implemented in Geant-4. In addition, the implications of $R$-hadron scattering for collider searches are discussed