46 research outputs found

    Temperature and masting control Norway spruce growth, but with high individual tree variability

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    Tree growth and reproduction are subject to trade-offs in resource allocation. At the same time, they are both influenced by climate. In this study, we combined long records of reproductive effort at the individual- (29 years), population- (41 years) and regional (up to 53 years) scale, and tree ring chronologies, to investigate the effects of climate and reproductive allocation on radial growth in an Alpine Norway spruce forest. Seed and cone production was highly variable between years (mean individual CV = 1.39, population CV = 1.19), but showed high reproductive synchrony between individuals (mean inter-tree correlation = 0.72). No long-term trend in reproductive effort was detected over four decades of observations. At the stand scale, cone production was dominated by a small number of individuals (\u201csuper-producers\u201d), who remained dominant over three decades. Individual tree growth responded positively to summer temperature, but the response to cone production varied between individual trees. Consequently, we found some evidence that mast years were associated with a divergence in growth between high and low cone producing individuals, and a decline in within-population growth synchrony. At the population level we found limited evidence of a relationship between growth and reproduction. Radial growth was lower than average in some mast years, but not in others. This was partly explained by summer temperature during the year of growth, with growth reductions restricted to mast years that coincided with colder than average summers. Regional mast records and tree ring chronologies provided some support to indicate that our results were consistent in other spruce stands, although the effect of mast years on growth appeared to vary between sites. Tree ring variation at the individual and population level, and between-tree growth synchrony are influenced by masting, and consequently dendrochronologists should consider both the occurrence of masting and the individual differences in reproductive effort when interpreting tree ring datasets. Our results also indicate that tree ring chronologies contain information to facilitate reconstruction of mast events, which will help address outstanding questions regarding the future response of masting to climate change

    Sustained seizure freedom with adjunctive brivaracetam in patients with focal onset seizures

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    The maintenance of seizure control over time is a clinical priority in patients with epilepsy. The aim of this study was to assess the sustained seizure frequency reduction with adjunctive brivaracetam (BRV) in real-world practice. Patients with focal epilepsy prescribed add-on BRV were identified. Study outcomes included sustained seizure freedom and sustained seizure response, defined as a 100% and a ≥50% reduction in baseline seizure frequency that continued without interruption and without BRV withdrawal through the 12-month follow-up. Nine hundred ninety-four patients with a median age of 45 (interquartile range = 32–56) years were included. During the 1-year study period, sustained seizure freedom was achieved by 142 (14.3%) patients, of whom 72 (50.7%) were seizure-free from Day 1 of BRV treatment. Sustained seizure freedom was maintained for ≥6, ≥9, and 12 months by 14.3%, 11.9%, and 7.2% of patients from the study cohort. Sustained seizure response was reached by 383 (38.5%) patients; 236 of 383 (61.6%) achieved sustained ≥50% reduction in seizure frequency by Day 1, 94 of 383 (24.5%) by Month 4, and 53 of 383 (13.8%) by Month 7 up to Month 12. Adjunctive BRV was associated with sustained seizure frequency reduction from the first day of treatment in a subset of patients with uncontrolled focal epilepsy

    Naturalizing Institutions: Evolutionary Principles and Application on the Case of Money

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    Increased lipid peroxidation in adult GH-deficient patients: effects of short-term GH administration

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    Abstract: Objective: Adult GH deficiency (GHD) syndrome is characterized by increased risk of atherosclerosis and hence of cardio- and cerebrovascular mortality. Oxidative stress appears to play an important role in early atherogenesis. Oxidized LDL represents an important predictor of cardiovascular risk and is mainly responsible for oxidative damage of the endothelium. Its concentrations are increased in GHD, but the association between this abnormality and oxidative stress is still unclear, due to the discordant results yielded by the few available studies. Design and methods: In 13 GHD patients, plasma lipid peroxide concentrations were measured before and after a 4-month treatment with recombinant human GH (rhGH) and compared with those of 13 age- and sex-matched controls. In the same subjects, the so-called "lag-time", an index of anti-oxidant activity and thus of plasma oxidative balance, was also measured using a fluorescence kinetics method. Results: Before treatment, peroxide levels were significantly higher in patients than in controls (374.0 +/- 31.52 vs 268.0 +/- 8.51 U.C., p < 0.01), whereas the lag-time was significantly lower (113.0 +/- 10.70 vs 168.0 +/- 7.80 min, p < 0.01). RhGH administration to patients resulted both in a significant decrease in lipid peroxide levels (from 374.0 +/- 31.52 to 336.0 +/- 33.17 U.C., p < 0.01) and a significant prolongation of lag-time (from 113.0 +/- 10.70 to 144.0 +/- 15.00 min, p < 0.01). After treatment, both parameters were no longer significantly different in patients and controls. Lag-time and peroxide levels at baseline did not show any correlation with IGF-I concentrations in GHD patients. After replacement therapy, however, lag-time was positively (r(2) = 0.62, p < 0.01), and peroxide levels negatively (r(2)=0.41, p < 0.05), correlated with IGF-I levels. Conclusions: These data support the view that adult GHD syndrome is characterized by an unbalance between pro- and anti-oxidant factors with marked preponderance of the former. This abnormality, likely contributing to the increased atherogenic risk of GHD patients, is corrected by short-term GH administration at a dose able to increase, although not to fully normalize, IGF-I levels

    Nephroangiosclerosis and Its Pharmacological Approach

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    Nephroangiosclerosis (NAS) is a major cause of progressive renal insufficiency. Hypertension is very important in the causation of NAS but other factors such as race, age, metabolic variables, and genetics play a pathogenic and prognostic role. A multifactorial treatment strategy, including antihypertensive, lipid-lowering and anti-platelet agents, could improve cardiovascular and renal outcomes in patients with vascular nephropathy
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