Changes in the activities of enzymes involved in nitrogen and sulphur assimilation during leaf and berry development of Vitis vinifera

The changes in the activities of 0-acetylserine sulphydrylase, ATP sulphurylase, glutamate dehydrogenase, glutamine synthetase and nitrate reductase in extracts from leaves and berries of Vitis vinifera L. cv. Merlot were studied at weekly intervals prior to anthesis up to grape harvest. Total nitrogen, amino nitrogen and protein contents were also determined.The total nitrogen content decreased from the beginning of the determinations either in leaves or in berries. Protein and amino nitrogen increments in berries matched their decreases in leaves.Nitrate reductase activity was not detectable either in leaves or berries. On the contrary, all the other examined enzymes showed at least three maxima of activity: one at anthesis and the others between the beginning of berry development and grape harvest.The ATP sulphurylase, 0-acetylserine sulphydrylase and glutamate dehydrogenase activities of berries were always higher than those observed in leaves, whereas glutamine synthetase activitywas similar in the two organs.Our results indicate that sulphur and nitrogen assimilation occur either in leavesor berries of grapevine.Changements des activités enzymatiques de l'assimilation de l'azote et du soufre pendant le développement de la feuille et du grain de Vitis viniferaSur des extraits de feuilles et de grains de raisins de Vitis vinifera L. cv. Merlot, prélevés chaque semaine dans la période entre la floraison et la vendange, les changements des activités enzymatiques de 1'0-acétylsérine sulfhydrilase, ATP sulfurylase, glutamate déshydrogénase, glutamine synthétase et de la nitrate réductase ont été étudiés.La teneur en azote total diminuait dans les feuilles aussi bien que dans les grains. L'accroissement des protéines et de l'amino-azote dans les grains était lié à leur décroissement dans les feuilles. L'activité enzymatique de la nitrate réductase n'a été retrouvée ni dans les grains ni dans les feuilles; toutes les autres activités enzymatiques analysées présentaient au moins trois pointes d'activités: la première à la floraison, les autres dans la période comprise entre le début du développement du grain et la vendange.Les activités de l'ATP sulfurylase, 0-acétylsérine sulfhydrilase et de la glutamate déshydrogénase étaient plus élevées dans les grains que dans les feuilles, tandis que l'activité de la glutamine synthétase était pareille dans les deux organes.Ces résultas indiquent que l'assimilation du soufre et de l'azote se fait dans les feuilles aussi bien que dans les grains de la vigne

Radiative Corrections to W and Quark Propagators in the Resonance Region

We discuss radiative corrections to W and quark propagators in the resonance region, |s-M^2| \lsim M*Gamma. We show that conventional mass renormalization, when applied to photonic or gluonic corrections, leads in next to leading order (NLO) to contributions proportional to [M*Gamma/(s-M^2)]^n, (n=1,2...), i.e. to a non-convergent series in the resonance region, a difficulty that affects all unstable particles coupled to massless quanta. A solution of this problem, based on the concepts of pole mass and width, is presented. It elucidates the issue of renormalization of amplitudes involving unstable particles and automatically circumvents the problem of apparent on-shell singularities. The roles of the Fried-Yennie gauge and the Pinch Technique prescription are discussed. Because of special properties of the photonic and gluonic contributions, and in contrast with the Z case, the gauge dependence of the conventional on-shell definition of mass is unbounded in NLO. The evaluations of the width in the conventional and pole formulations are compared and shown to agree in NLO but not beyond.Comment: 19 pages, 7 figures, LaTeX (uses epsfig). Slight rewording of the abstract and one of the sentences of the text. Minor misprints corrected. To appear in Phys. Rev.

Laparoscopy for extraperitoneal rectal cancer reduces short-term morbidity: Results of a systematic review and meta-analysis

BACKGROUND: The role of laparoscopy in the treatment of extraperitoneal rectal cancer is still controversial. The aim of the study was to evaluate differences in safety of laparoscopic rectal resection for extraperitoneal cancer, compared with open surgery. MATERIALS AND METHODS: A systematic review from 2000 to July 2012 was performed searching the MEDLINE and EMBASE databases (PROSPERO registration number CRD42012002406). We included randomized and prospective controlled clinical studies comparing laparoscopic and open resection for rectal cancer. Primary endpoints were 30-day mortality and morbidity. Then a meta-analysis was conducted by a fixed-effect model, performing a sensitivity analysis by a random-effect model. Relative risk (RR) was used as an indicator of treatment effect. RESULTS: Eleven studies, representing 1684 patients, met the inclusion criteria: four were randomized for a total of 814 patients. Mortality was observed in 1.2% of patients in the laparoscopic group and in 2.3% of patients in the open group, with an RR of 0.56 (95% CI 0.19–1.64, p = 0.287). The overall incidence of short-term complications was lower in the laparoscopic group (31.5%) compared to the open group (38.2%), with an RR of 0.83 (95% CI 0.73–0.94, p = 0.004). Surgical complications, wound complications, blood loss and the need for blood transfusion, time for bowel movement recovery, food intake recovery, and hospital stay were significantly lower or less frequent in the laparoscopic group. The incidence of intra-operative injuries, anastomotic leakages, and surgical re-interventions was similar in the two groups. Only operative time was in favour of the open group. CONCLUSIONS: Based on the evidence of both randomized and prospective controlled series, mortality was lower after laparoscopy although not significantly so, while the short-term morbidity RR, including subgroup analysis, was significantly lower after laparoscopy for extraperitoneal rectal cancer compared to open surgery

A New Renormalization Scheme of Fermion Fields in Electroweak Standard Model

This paper has been withdrawn by the author,due a immature idea.Comment: 6 page

[-2]proPSA versus ultrasensitive PSA fluctuations over time in the first year from radical prostatectomy, in an high-risk prostate cancer population: A first report

BACKGROUND: [−2]proPSA and its derivatives have an higher diagnostic accuracy than PSA in predicting prostate cancer (PCa). In alternative to PSA, ultrasensitive PSA (uPSA) and [−2]proPSA could be potentially useful in recurrent disease detection. This research focused on [−2]proPSA and uPSA fluctuations over time and their possible clinical and pathological determinants, in the first year after RP. METHODS: A cohort of 106 consecutive patients, undergoing RP for high-risk prostate cancer (pT3/pT4 and/or positive margins), was enrolled. No patient received either preoperative/postoperative androgen deprivation therapy or immediate adjuvant RT, this latter for patient choice. [−2]proPSA and uPSA were measured at 1, 3, 6, 9, 12 months after RP; their trends over time were estimated by the mixed-effects linear model. The uPSA relapse was defined either as 3 rising uPSA values after nadir or 2 consecutive uPSA >0.2 ng/ml after RP. RESULTS: The biochemical recurrence (BCR) rate at 1 year after RP was either 38.6 % (in case of 3 rising uPSA values) or 34.9 % (in case of PSA >0.2 ng/ml after nadir), respectively. The main risk factors for uPSA fluctuations over time were PSA at diagnosis >8 ng/ml (p = 0.014), pT (p = 0.038) and pN staging (p = 0.001). In turn, PSA at diagnosis >8 ng/ml (p = 0.012) and pN (p < 0.001) were the main determinants for [−2]proPSA trend over time. In a 39 patients subgroup, uPSA decreased from month 1 to 3, while [−2]proPSA increased in 90 % of them; subsequently, both uPSA and [−2]proPSA increased in almost all cases. The [−2]proPSA trend over time was independent from BCR status either in the whole cohort as well in the 39 men subgroup. CONCLUSIONS: Both uPSA and [−2]proPSA had independent significant fluctuations over time. PSA at diagnosis >8 ng/ml and pathological staging significantly modified both these trends over time. Since BCR was not confirmed as determinant of [−2]proPSA fluctuations, its use as marker of early biochemical relapse may not be actually recommended, in an high-risk prostate cancer patients population

Some model-independent phenomenological consequences of flexible brane worlds

In this work we will review the main properties of brane-world models with low tension. Starting from very general principles, it is possible to obtain an effective action for the relevant degrees of freedom at low energies (branons). Using the cross sections for high-energy processes involving branons, we set bounds on the different parameters appearing in these models. We also show that branons provide a WIMP candidate for dark matter in a natural way. We consider cosmological constraints on its thermal and non-thermal relic abundances. We derive direct detection limits and compare those limits with the preferred parameter region in the case in which the EGRET excess in the diffuse galactic gamma rays is due to dark matter annihilation. Finally we will discuss the constraints coming from the precision tests of the Standard Model and the muon anomalous magnetic moment.Comment: 10 pages, 6 figures. Contribution to the Proceedings of the Second International Conference on Quantum Theories and Renormalization Group in Gravity and Cosmology, IRGAC 2006, Barcelona, 11-15 July, 200

Width and Partial Widths of Unstable Particles in the Light of the Nielsen Identities

Fundamental properties of unstable particles, including mass, width, and partial widths, are examined on the basis of the Nielsen identities (NI) that describe the gauge dependence of Green functions. In particular, we prove that the pole residues and associated definitions of branching ratios and partial widths are gauge independent to all orders. A simpler, previously discussed definition of branching ratios and partial widths is found to be gauge independent through next-to-next-to-leading order. It is then explained how it may be modified in order to extend the gauge independence to all orders. We also show that the physical scattering amplitude is the most general combination of self-energy, vertex, and box contributions that is gauge independent for arbitrary s, discuss the analytical properties of the NI functions, and exhibit explicitly their one-loop expressions in the Z-gamma sector of the Standard Model.Comment: 20 pages (Latex); minor changes included, accepted for publication in Phys. Rev.