Modeling of urea degradation in white and rosé wines by acid urease

The specific activity of a whole cell acid urease preparation was tested in five wines manufactured in the Apulia region of Italy in the 2003 vintage at both short and long treatment times, thus confirming the validity of the pseudo-first-order kinetic model to describe urea removal in real wines. The ratio between the experimental pseudo-first-order kinetic rate constant (kIe) for any real wine tested and that (kI) referred to a model wine solution having the same composition and pH reduced from about 0.21 to 0.02 as the overall content of phenolic compounds (P) increased from 109 to 853 g m-3 of gallic acid equivalent (GAE). The specific inhibitory effect of such compounds was explained by accounting for the equilibrium constant (KP) of the reaction of polyphenols with acid urease, which was found to be about 21 g of GAE m-3 for the real wines tested, whereas it ranged from about 16 to 45 g of GAE m-3 when the model wine solution was enriched with tannins extracted from grape seeds or skins, respectively. A sequential experimental procedure consisting of accelerated acid urease tests at high doses of enzyme followed by accelerated ethyl carbamate tests on the resulting acid urease treated wine was recommended to assess preliminarily the technoeconomic feasibility of the acid urease hydrolytic process for the wine of concern. Keywords: Acid urease; real and model wines; phenolics; pseudo-first-order kinetic rate constant; inhibitory effect; urea degradation kinetics.     

Time trend in reference evapotranspiration: analysis of a long series of agrometeorological measurements in Southern Italy

This study aims to evaluate the potential effects of the climatic variations on the reference evapotranspiration (ET₀) and, consequently, on the crop water requirements in the Apulian Tavoliere, one of the largest irrigated districts of Southern Italy. To reach this purpose, both climatic parameters (air temperature and rainfall) and estimated water requirements of ??processing?? tomato (among the most representative irrigated crops in the district since the mid-1970s and, therefore, chosen as a study-case) were analyzed in order to find out if a time trend exists or does not. The analysis covered the period from 1957 to 2008. The analysis showed that the rainfall amounts decreased (?3.4 mm per year in the analyzed period), while air temperature increased (0.18 °C and 0.25?°C per decade for minimum and maximum, respectively). As a consequence of the climatic variation during the considered period, a growth trend of the ET₀ (1.4 mm per year) and water deficit (3.2 mm per year) took place. As a consequence, the water amounts for irrigating the same crop in the considered period were growing. This increased consumption is in agreement with the perception of the farmers of the district but never documented. Through the FAO AquaCrop model, the tomato irrigation water requirements have been simulated during the considered period. The trend analysis of the seasonal evapotranspiration values simulated in 52 years confirmed the increase in tomato water requirements (0.7 mm per year).     

Assessment of urea degradation rate in model wine solutions by acid urease from Lactobacillus fermentum

The specific activity (piA) of a whole cell acid urease preparation was assessed in model wine solutions at different levels of malic (M) and lactic acids, metabisulfite, ethanol, and pH by performing a central composite design. M and then pH were found to be the most controlling variables, their effects being practically coincident but of opposite sign. For urea concentrations up to approximately 1 mol m(-3) the ammonium formation rate was assumed of the pseudo-first-order with respect to urea, this being confirmed by two independent validation tests performed at 20 degrees C for as long as 24 h. In the case of real wines the effective pseudo-first-order kinetic rate constants were found to be smaller than those pertaining to the model solutions having the same wine composition and pH by a factor varying from 10 to 1000, this affecting significantly the specific urease treatment costs per liter of wine treated.     

Cone beam computed tomography in the diagnosis of temporomandibular joint alterations in cats

The aim of this study was to describe the use of cone beam computed tomography as an auxiliary method to diagnose changes to the temporomandibular joints in cats. We used five cats of various ages, breeds and genders that showed clinical signs consistent with changes in the temporomandibular joint. Cone beam computed tomography enables a complete and thorough examination of the temporomandibular joints by allowing the evaluation of selected images as a whole. It also enables the identification of all anatomical structures and any changes that may be present. The results showed that this method is effective in confirming or ruling out changes in the temporomandibular joint in cats, such as disjunctions of the palatine raphe; fractures of the mandibular symphisis, zygomatic bone and condylar; and dental resorption.     

High Rate Composting with Innovative Process Control

Despite the variety of composting plants present on the market, the design and operation of composting systems to improve the rate of the process and quality of end products are still an objective that has not been achieved. The composting process evolves through a thermophilic phase followed by a mesophilic one. The metabolism of microorganisms involved in the process is deeply disturbed by environmental changes like temperature, oxygen level and moisture. The aim of this study was to carry out a composting process in two separate reactors: the first, only in the thermophilic phase, with the purpose of pathogen destruction and decomposition by selected thermophilic microorganisms; the second, only in the mesophilic phase, to perform the main microbial transformations with a higher rate of volatile solids destruction. The results confirmed that maintaining constant the main parameters which affect the process, the microbial activity is enhanced. In the two-phase process, the evolution of parameters like moisture, organic carbon, humified organic matter, organic N, C/N and germination index (phytotoxicity) is more rapid relative to the single phase process. Also pathogen destruction is improved with the complete elimination of Faecal coliforms and Enterobacteriaceae and with a stronger reduction of Faecal streptococci.     

Modelling the event-based hydrological response of olive groves on steep slopes and clayey soils under mulching and tillage management using the SCS-CN,Horton and USLE-family models

The SCS-CN, Horton and USLE-family models are used worldwide, but few examples are available for olive groves on steep and clayey soils under mulching of pruning residues. We evaluate the accuracy in predicting runoff and soil loss of a steep (20%) and clayey olive grove subject to three soil conservation practices: mechanical tillage (MT), mulching with pruning residues (NTR) and standard protection (SP), measured at plot scale in Southern Italy during 30 months under natural rainfall. The models were calibrated by adjusting the Curve Numbers (for the SCS-CN model) and the C-factors (MUSLE and USLE-M); the Horton model was not calibrated. The model performance was assessed by qualitative and quantitative procedures. In all practices, the SCS-CN was more accurate for runoff predictions (mean difference of 7% compared with corresponding observations) compared with the Horton (mean difference of 30%). For soil erosion, the MUSLE showed better performance in soils subject to MT or total protection (differences lower than 10%), while the USLE-M was more reliable to simulate soil loss in mulched plots (differences of 8%). A set of Curve Numbers (95 for MT, 70 for SP and 85 for NTR) and C-factors (0.4 for MT, 0.2 for SP and 0.1 for NTR) are proposed for applications in steep slope and clayey soil olive orchards using the SCS-CN and USLE proposed models, respectively. Validation exercises in other environmental experimental conditions would enhance the export these models for runoff and erosion control in agricultural soils treated with mulching.     

Physiological responses of Quercus ilex Leaves to Water Stress and Acute Ozone Exposure Under Controlled Conditions

The combined effect of water stress and ozone (O₃) on stomatal O₃ flux, damage to photosynthesis, and detoxification by biogenic volatile organic compounds (BVOC) in Quercus ilex leaves was studied. A 4-weeks O₃ exposure (250 ppb, 4 h per day) caused a reduction of photosynthesis and stomatal conductance, which was fully recovered 1 week after the end of the treatment, in well-watered and water-stressed plants. Measurements of stomatal O₃ flux revealed a low stomatal flux of the pollutant, which became minimal after stomatal closure caused by water stress. An induction of volatile monoterpenes, important compounds in the O₃ scavenging system in Q. ilex, and a burst of lipoxygenase compounds (LOX), which are released as gaseous by-products of membrane peroxidation, was observed after 2–3 weeks of O₃ fumigation. However, these compounds were also released in control leaves that were exposed to ozone only briefly, to determine stomatal O₃ flux. The low stomatal flux that occurred in water stress conditions helped avoiding permanent damage to Q. ilex leaves, although during the O₃ treatment photosynthesis was severely limited by stomatal closure. In well-watered plants, O₃ fumigation caused a noticeable increase of nocturnal stomatal conductance. If confirmed on adult plants under field conditions, this effect can imply larger flux of O₃ at night and possible detrimental effects of O₃ on leaf functions in plants exposed to high nocturnal O₃ levels.