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Background: A significant number of patients experience recurrent atrial fibrillation (AF) after ablation. Various risk scores have been described that may predict outcomes after AF ablation. In this study, we aimed to compare ten previously described risk scores with regard to their predictive value for post-ablation AF recurrence and procedural complications. Methods: A total of 482 AF patients (63% paroxysmal AF, 66% male, mean age 62 ± 9 years) undergoing initial radiofrequency pulmonary vein isolation (PVI) were included in the present analysis. Prior to ablation, all patients underwent both transthoracic echocardiography (TTE) and either cardiac CT imaging or CMR imaging. The following risk scores were calculated for each patient: APPLE, ATLAS, BASE-AF 2, CAAP-AF, CHADS 2, CHA 2DS 2-VASc, DR-FLASH, HATCH, LAGO and MB-LATER. Results: Median follow-up was 16 (12–31) months. AF recurrence after a 90-day blanking period was observed in 199 patients (41%), occurring after a median of 183 (124–360) days. AF recurrence was less frequent in paroxysmal AF patients compared to non-paroxysmal AF patients (34% vs. 54%, p < 0.001). Overall periprocedural complication rate was 6%. All scores, except the HATCH score, demonstrated statistically significant but poor predictive value for recurrent AF after ablation (area under curve [AUC] 0.553–0.669). CHA 2DS 2-VASc and CAAP-AF were the only risk scores with predictive value for procedural complications (AUC 0.616, p = 0.043; AUC 0.615, p = 0.044; respectively). Conclusions: Currently available risk scores perform poorly in predicting outcomes after AF ablation. These data suggest that the utility of these scores for clinical decision-making is limited.

Objective. To present the effects of a relatively modest environmental intervention on biological cardiovascular risk indicators. Method. A controlled trial, including two worksites. Measurements (i.e., body composition, blood pressure and serum cholesterol) took place at baseline and at 3- and 12-month follow-up. The 12-month environmental intervention (The Hague, The Netherlands, 2004) consisted of: a ‘Food’-part: to stimulate healthier food choices by means of product information in the canteen, and a ‘Steps’-part: focused on stimulating stair use by means of motivational prompts in staircases and on elevator doors. Results. Significant differences in change between groups ( n = 540) in favor of the intervention group were found on: [1] total cholesterol for women (− 0.35 mmol/l); [2] HDL for men at 3 months (0.05 mmol/l) and 12 months (0.10 mmol/l); and [3] the total–HDL ratio for the total intervention group at 3 and 12 months (− 0.45 mmol/l). Both groups showed a decrease in all body composition values at both follow-ups. A significant difference in change in systolic BP was found in favor of the control group (∼ 4 mm Hg), due to an increase in the intervention group at both follow-ups. Conclusions. Based on the contrasting results, this modest environmental intervention was ineffective in reducing cardiovascular risk in a population of office workers.

The temperature dependence of chlorophyll fluorescence induction and photosynthesis of tomato plants grown at different temperatures and light intensities was studied. Chlorophyll fluorescence induction and photosynthetic activity of leaf discs was determined between 0-degrees and 30-degrees-C. Two breakpoints, around 16-degrees and 24-degrees-C, were observed when the maximum of chlorophyll fluorescence induction, F(p), was plotted against temperature. DCMU was used to study the role of photosynthetic electron transport on the breakpoints of F(p). Inhibition of photosynthetic electron transport by DCMU caused the disappearance of the breakpoint at 16-degrees-C. The temperature breakpoint at 24-degrees-C remained intact. This result is used to discuss the mechanisms underlying the occurrence of the breakpoints. The low temperature breakpoint at 16-degrees-C was ascribed to electron transport limitation between photosystem I and photosystem II at temperatures below 16-degrees-C. The high temperature breakpoint was attributed to alterations in light distribution between photosystem I and photosystem II. An increased State II adaptation at temperatures above 24-degrees-C is believed to cause a decrease in F(p). Temperatures of both breakpoints were affected by growth conditions of the tomato plants. Compared with optimal growth conditions, suboptimal growth conditions caused a significant decrease in the low temperature breakpoint. Concomitantly, photosynthetic activity and leaf chlorophyll content were decreased. The possibility of using breakpoint temperatures to indicate an adaptation of the thylakoid membrane organisation and functioning to suboptimal growth conditions is discussed.

A very short proof of a no-go theorem for putting fermions on a lattice is given using the Poincare-Hopf theorem. The no-go theorem forbids the lattice formulation of theories with handed fermions without species doubling. Examples of such theories are chiral invariant QCD and the Weinberg-Salam-Glashow model. We give arguments why it could be possible to circumvent the no-go theorem by relaxing one of the assumptions, viz. bilinearity of the action in the fermion fields.

We investigate the formulation of fermions in lattice gauge theories, in weak coupling perturbation theory. It is shown that a lattice fermion formulation without species doubling and with explicit continuous chiral symmetry is impossible. We interpret this as a manifestation of the triangle anomaly. Green functions and (axial) vector flavor currents in lattice QCD with Wilson fermions are studied. We show that in the (weak coupling) continuum limit the theory is equivalent to perturbative continuum QCD: chiral invariant and with the usual anomaly in the flavor singlet axial current.

The continuum limit of a lattice gauge theory is studied, using a gradient prescription for fermion fields which satisfies axial gauge invariance. It is found that both the axial vector and polar vector Ward identifies are satisfied for the fermion triangle diagram. However, Lorentz invariance and locality are violated, unless one introduces appropriate counter terms or more fermions.

In this letter we calculate the vacuum polarization in the one-loop approximation in QED on a lattice. We construct the fermion lattice action following the SLAC prescription. The vacuum polarization appears non-covariant and non-local in the continuum limit.