Assimilate transport in grapevines -effect of phloem disruption

Assimilate translocation in mature grapevines (cv. Gewürztraminer and cv. Harslevelü) under field conditions was investigated during the growth season by quantifying individual sugars and organic acids in mature leaves, shoot bark and berries, as affected by girdling the shoot just above the bunches. Tissue was sampled at berry set, pea size, veraison and ripeness stages of the vine. Invertase activity was determined in the shoot bark at ripeness. In the leaves, malic acid concentrations reached lowest levels at pea size, but increased thereafter. Tartaric acid decreased after peaking at pea size stage. Tartaric acid concentrations increased with girdling. Despite the increase in leaf age, sucrose concentrations remained virtually stable during the season, emphasising the importance of mature leaves for nourishing bunches. Girdling resulted in a build‐up of sucrose in the leaves. In the bark, malic and tartaric acid stayed more or less the same during the growth period, but increased above the girdle. As a result of phloem disruption, sucrose also increased. The increase in glucose and tartaric acid is believed to result from catabolic cleavage of sucrose by invertase. Invertase activity was evident in the bark (of mature Harslevelü vines) at ripeness, which may indicate involvement in osmotic adjustments and gradients in the bark/phloem structure. In the berries, malic and tartaric acids reached peak concentrations at pea size. The volume increase during the ripening period, and in the case of malic acid also respiratory loss, resulted in a decrease in organic acid concentration. Malic acid continued to decrease after the initial decline, whereas tartaric acid stayed virtually stable. Girdling had no marked effect on organic acid accumulation in the berries. Sucrose concentrations were low during the first part of the season, but increased thereafter. Sucrose concentrations during ripening increased with girdling, which may represent a concentration effect and/or import from the rest of the vine. Sucrose concentrations (in mature Harslevelü vines) were indeed lower below than above the girdle. Comparison of sucrose concentrations in the leaves, bark and berries showed the existence of a decreasing concentration gradient, in line with the source:sink transport concept. An equally prominent decrease in sucrose:glucose ratio in the berries from the start of the ripening period indicates that vacuolar integrity (compartmentation) was affected in the ripening berry, most probably allowing hydrolysis of sucrose by invertase and decreasing osmotic potential within the berry. The results provide further evidence for the hypothesis of an osmotic gradient driven transport to the berry.     

The Fate of Heavy Metals in Pilot-Plant Scale Upflow Sludge-Blanket Clarifiers

T he R emoval of heavy metals and aluminium residuals during upflow sludge-blanket clarification was investigated using a pilot-plant system. Pilot units treating predosed raw water on site were assessed for sludge-blanket formation and stabilization, and were found to produce clarified water of a comparable quality to the main works units after the start-up and stabilization periods were complete. The heavy metals Cr, Fe, Mn, and Ni were the only heavy metals detectable at the investigation site and these occurred at concentrations well below guidelines values for potable abstraction and supply.
Mean removals of Fe, Mn, Cr, and Ni were about 98, 89, 51, and 30 per cent respectively, during steady-state operation, and Fe, Mn, and Cr all displayed reduced removals during transient changes in surface load, whereas Ni removal appeared to be relatively independent. Aluminium residuals derived from the dosed alum coagulant also showed decreases in removal from about 83 per cent during steady-state operation to between 40 and 50 per cent during transient experiments.     

A simple method to create buttonhole cannulation tracks in a busy hemodialysis unit

The preference for fistulae as the hemodialysis access of choice has led to a significant number of accesses that are less than ideal for cannulation. Buttonhole cannulation is ideal for such accesses, but the technique for creation provides major challenges. In 12 patients, buttonhole tunnel tracks were created by leaving the polyurethane catheter of a Clampcath^® hemodialysis needle indwelling for 10 days after the initial cannulation. After each dialysis the catheter was flushed, and dressed with an antibacterial ointment and gauze. Dialysis was carried out via the catheter during that time. After day 10, the catheter was removed, the tunnel track covered with an antibacterial dressing and the tunnel track was cannulated with a dull buttonhole needle at the next dialysis. Successful buttonhole accesses were created in 11 patients after 10 days, the 12th patient required a single sharp needle cannulation before using dull needles. During the first 2 weeks of dull needle cannulation both pain experienced on cannulation and the difficulty cannulating the access were significantly less than in the classical buttonhole technique (P<0.01). Complications during the follow-up period (6 months–1.5 years) included difficulty cannulating with a dull needle (22) and antibacterial agent induced contact dermatitis (4). There was no episode of sepsis or tunnel track infection. Initial cannulation of the fistula using a Clampcath^® hemodialysis needle, leaving the polyurethane catheter indwelling for 10 days, is a simple, safe, and effective technique for the creation of buttonhole tunnel tracks.     

Skim milk powder for use in cream of tomato soup

The suitability of dried skim milk for incorporation in cream of tomato soup has been considered. The effect of changing powder protein content and heat classification on the texture and viscosity of cream of tomato soup was studied against a background of contrasting recipes and process conditions. The properties of the soup were shown to be insensitive to changes in powder properties.     

Transfer of antibiotics between the udder quarters of dairy cows treated for clinical mastitis

Milk samples from all quarters of 13 dairy cows, each treated with an antibiotic preparation for clinical mastitis in one quarter, were collected at each milking during treatment and for at least six milkings thereafter. After storage at —25 °C, these were tested for the presence of antibiotics. Transfer to untreated quarters was found in eight of the 13 cases studied, although in only two cases was the level in untreated quarters greater than 0.01 μ/ml. The main factor affecting transfer was found to be a history of infection in the treated quarter. This was observed in all but one case where transfer had occurred. During the period of study incorporation of milk from untreated quarters would not have raised the antibiotic level in the bulk supply to a level which would have incurred a financial penalty.