Our data indicate that exercise favourably affects angiogenesis and improves LV remodelling and contractility reserve in a rat model of severe chronic HF.

Field experiments were conducted in Sicily (south Italy) to assess chlorophyll (Chl) fluorescence parameters in response of potato crop to nitrogen dose, to variation in genotype and in plant age, and to detect relationships between Chl content, fluorescence parameter F v /F m , and tuber yield. The experiment included five nitrogen doses (0, 10, 20, 30, and 40 g m -2 ) and four genotypes (Spunta, Sieglinde, Daytona, and Igea). Chl fluorescence parameters (initial fluorescence, F 0 , maximum fluorescence, F m , variable fluorescence, F v , F v /F m , T max (the time required to reach F m ), and Chl content were measured weekly between the appearance of the fifth and sixth leaves and the onset of plant senescence. A positive linear relationship was established between nitrogen supply and Chl content, F 0 , and T max . Nitrogen supply up to 10 g m -2 also had a positive effect on F m and F v , but above this rate it reduced F v /F m . Spunta had the highest Chl content, F m , F v , and F v /F m , but the lowest F 0 , whereas Sieglinde had the lowest Chl content, F v , F v /F m , and T max and the highest F 0 . The cvs. Igea and Daytona exhibited intermediate Chl fluorescence parameters. Chl content and T max decreased with increasing plant age, whereas F 0 , F m , and F v increased until complete canopy development and thereafter declined until crop maturity. Tuber and plant dry matter yield were significantly correlated with Chl content, F 0 , and T max . Thus Chl fluorescence and content detect differences in the response of potato to N supply, can discriminate between genotypes, predict plant age, and yield performance under field conditions.

Cardiac beta-adrenergic receptor (beta-AR) signaling and left ventricular (LV) responses to beta-AR stimulation are impaired with aging. It is shown that exercise and beta-AR blockade have a favorable effect on cardiac and vascular beta-AR signaling in several cardiovascular diseases. In the present study, we examined the effects of these two different strategies on beta-AR dysregulation and LV inotropic reserve in the aging heart. Forty male Wistar-Kyoto aged rats were randomized to sedentary, exercise (12 wk treadmill training), metoprolol (250 mg.kg(-1).day(-1) for 4 wk), and exercise plus metoprolol treatment protocols. Ten male Wistar-Kyoto sedentary young rats were also used as a control group. Old trained, old metoprolol-treated, and old trained plus metoprolol-treated rats showed significantly improved LV maximal and minimal first derivative of the pressure rise responses to beta-AR stimulation (isoproterenol) compared with old untrained animals. We found a significant reduction in cardiac sarcolemmal membrane beta-AR density and adenylyl cyclase activity in old untrained animals compared with young controls. Exercise training and metoprolol, alone or combined, restored cardiac beta-AR density and G-protein-dependent adenylyl cyclase activation in old rats. Although cardiac membrane G-protein-receptor kinase 2 levels were not upregulated in untrained old compared with young control rats, both exercise and metoprolol treatment resulted in a dramatic reduction of G-protein-receptor kinase 2 protein levels, which is a further indication of beta-AR signaling amelioration in the aged heart induced by these treatment modalities. In conclusion, we demonstrate for the first time that exercise and beta-AR blockade can similarly ameliorate beta-AR signaling in the aged heart, leading to improved beta-AR responsiveness and corresponding LV inotropic reserve.

Exercise training has been reported to exert beneficial effects on cardiac function and to reduce morbidity and mortality of chronic heart failure (HF). Augmented sympathetic nervous system (SNS) activity, leading to elevated circulating catecholamine (CA) levels, is a hallmark of chronic HF that significantly aggravates this disease. Exercise training has been shown to also reduce SNS overactivity in HF, but the underlying molecular mechanism(s) remain unidentified. We recently reported that adrenal G protein-coupled receptor kinase-2 (GRK2), an enzyme that regulates the sympathoinhibitory alpha(2)-adrenoceptors (alpha(2)-ARs) present in the CA-producing adrenal medulla, is upregulated in HF, contributing to the chronically elevated CA levels and SNS activity of the disease. In the present study, we tested whether exercise training can affect the adrenal GRK2-alpha(2)-AR-CA production system in the context of HF. For this purpose, a 10-wk-long exercise training regimen of adult male Sprague-Dawley rats starting at 4 wk postmyocardial infarction (post-MI) was employed, and examination at the end of this treatment period revealed significant amelioration of beta-AR-stimulated contractility in response to exercise training, accompanied by cardiac GRK2 reduction and restoration of circulating plasma CA levels. Importantly, adrenal GRK2 expression (72 + or - 5% reduction vs. post-MI untrained) and alpha(2)-AR number were also restored after exercise training in post-MI animals. These results suggest that exercise training restores the adrenal GRK2-alpha(2)-AR-CA production axis, and this might be part of the mechanism whereby this therapeutic modality normalizes sympathetic overdrive and impedes worsening of the failing heart.

Orobanche crenata Forsk. is a widespread holoparasite weed that inflicts severe damage (yield reduction can reach up to 100%) on legume crops in the Mediterranean and West Asian regions. In Italy and Spain, faba bean crop (Vicia faba L.) area has drastically decreased in the last four decades mainly due to O. crenata infection. The effectiveness of soil solarization for controlling O. crenata in heavily and naturally infested fields of faba bean in Sicily (south Italy) was studied during two growing seasons. Ploughed, leveled and moistened soil was mulched with transparent polyethylene sheets for about 50 days from the end of July to early September. The residual effect of solarization was also investigated the next year in season one and two, respectively. Mulching increased mean daily maximum temperatures of the soil by 8.9°C and 10.7°C at 5 cm depth and 11.5°C and 11.3°C at 15 cm depth. Solarization achieved a total control of O. crenata, since no shoots emerged from the treated soil. In contrast, in non-solarized plots shoots of O. crenata emerged and were present at high intensity (from 13 to 44 shoots per faba bean plant), impeding the faba bean plants from producing flowers, pods and seeds. Soil solarization improved faba bean growth and consequently grain yield compared with non-solarized soil. The almost complete control of O. crenata and improvement of growth and grain yield of faba bean were also maintained the next year. soil solarization / crenate broomrape emergence / Vicia faba growth / soil temperature / residual effect Résumé-La solarisation du sol, une technique non chimique pour contrôler Orobanche crenata et améliorer le rendement de la fève. Orobanche crenata Forsk. est une adventice holo-parasite, très répandue, qui inflige de sévères dommages aux cultures légumineuses (la réduction du rendement peut parvenir à 100 % dans les régions de la Méditerranée et de l'Asie occidentale). En Italie et en Espagne, les cultures commerciales de fèves (Vicia faba L.) ont subi une forte réduction dans les 40 dernières années, principalement à cause de l'infestation par O. crenata. Durant deux saisons on a conduit des essais de plein champ en Sicile (sud de l'Italie) pour étudier l'efficacité de la solarisation dans la lutte contre O. crenata. Le sol, travaillé précédemment, nivelé et arrosé, a été couvert d'un paillage plastique en polyéthylène transparent de 20 µm d'épaisseur durant environ 50 jours à partir de la fin juillet jusqu'à début septembre. De plus, l'année suivante, on a évalué les effets résiduels de la solarisation. Le paillage a augmenté respectivement la température moyenne journalière maximale du sol de 8,7°C et 10,7°C à une profondeur de 5 cm et de 11,5°C et 11,3°C à une profondeur de 15 cm. La solarisation a permis un contrôle total d'O. crenata, étant donné qu'aucun bourgeon d'orobanche n'a émergé du sol traité. Par contre, dans les champs non traités avec la solarisation, les bourgeons d'O. crenata ont été nombreux à émerger