The effectiveness of ozone and acidulant treatments in extending the refrigerated shelf life of fresh-cut potatoes

Abstract: The objective of the study was to determine the effectiveness of acidulant dip treatments (with or without aqueous ozone) to reduce enzymatic browning and to extend the shelf life of fresh‐cut potato slices during refrigerated storage (4 °C) for 28 d. Potato slices subjected to aqueous ozone (2 ppm) had significantly (P≤ 0.05) higher L‐values and lower a‐values, but ozone did not appear to have any effect on aerobic plate counts (APCs) or polyphenol oxidase (PPO) activity. NatureSeal (NS) and sodium acid sulfate (SAS) were the most effective acidulant treatments in reducing browning (significantly [P≤ 0.05] higher L‐values, lower a‐values, and browning index values) regardless of ozone treatment. NS and SAS also had lower PPO activity compared to other treatments on days 0 and 28, and significantly (P≤ 0.05) lower APCs (≤2.00 log CFU/g) over refrigerated storage. Therefore, the SAS treatment was comparable to NS, a commercially available product, and showed promise as an effective antibrowning dip to reduce browning and spoilage in fresh‐cut potato products. Practical Application: A 1% SAS dip treatment which included 1% citric and 1% ascorbic acid was found to be an effective antibrowning dip for fresh‐cut potatoes along with NatureSeal®'s PS‐10, compared to other treatments. They were both effective in maintaining low microbial counts over refrigerated storage. Additionally, aqueous ozone washes (2 ppm) showed significant benefits to reduce browning; however, ozone did not affect microbial counts or PPO enzyme activity. Therefore, the SAS treatment could have potential use in the fruit and vegetable industry to reduce browning and spoilage in fresh‐cut potato products.     

Sleep position, autonomic function, and arousal

AIMS: To investigate and compare heart rate variability (HRV) and responses of heart rate and arousal to head-up tilting in infants sleeping prone and supine. METHODS: Thirty seven healthy infants aged 2-4 months were studied. HRV was measured for 500 beats while they were in a horizontal position. Subjects were then tilted 60 degrees head-up, and heart rate recorded over 1 minute and arousal responses observed. Data were collected during both quiet and active sleep for both prone and supine sleep positions. RESULTS: HRV, as assessed by the point dispersion of Poincaré plots, was significantly reduced in the prone position for both sleep states. Sleep position did not influence the changes in heart rate seen during a head-up tilt. Full awakening to the tilt was common in active sleep but significantly less so in the prone position (15% of prone tests vs 54% supine). Full awakening to the tilt rarely occurred during quiet sleep in either sleep position. CONCLUSION: This study provides some evidence that blunted arousal responses and/or altered autonomic function are a feature of the prone sleeping position. Decreased HRV may be a sign of autonomic impairment. It is seen in many disease states and in infants who later die of sudden infant death syndrome (SIDS).     

A smooth-walled spline-profile horn as an alternative to the corrugated horn for wide band millimeter-wave applications

At millimeter-wave frequencies, corrugated horns can be difficult and expensive to manufacture. As an alternative we present here the results of a theoretical and measurement study of a smooth-walled spline-profile horn for specific application in the 80-120 GHz band. While about 50% longer than its corrugated counterpart, the smooth-walled horn is shown to give improved performance across the band as well as being much easier to manufacture.     

A computationally efficient algorithm for enhancing linear features in images

We present a computationally efficient algorithm for highlighting long linear features in images. The algorithm is based on the recursive binary decomposition of the image into subimages that have been line enhanced along different directions. After a number of successive decompositions, the subimages are recombined to yield a line enhanced image. The performance of the algorithm is similar to that of rotating-kernel-type enhancement routines. However, the new algorithm can be executed much faster, making it ideal for use on large noisy images such as those provided by synthetic aperature radar.     

Laminar Surface Water Flow over Vegetated Ground

This study examines low Reynolds number flow over vegetated sloping ground. Instead of using the traditional empirical formula related to resistance or frictional roughness, a new approach is presented by considering the flow inside the vegetation layer as porous media flow governed by Biot’s poroelastic theory as well as inside the soil layer. There is a discrepancy in the velocity distributions of flow over vegetative mantle area and bare area, respectively. Due to the change of the vegetation density, the effects of vegetation porosity and vegetation blockage on surface water flow are discussed.     

In-vitro photobactericidal activity of aminoacridines

We report four patients with severe erythrodermic, pustular psoriasis, or plaque-type psoriasis, who were treated with a combination of acitretin and bath PUVA. After 4 weeks out-patient treatment, the psoriasis in all patients had improved by > or = 90%. No patient had relapsed when reviewed at 3 months. No significant side-effects were seen with the combined retinoid/bath PUVA treatment. Acitretin and bath PUVA may be safely combined for the treatment of severe psoriasis.     

Options for diabetic patients with chronic heel ulcers

Which are the determinants of return to work in middle aged myocardial infarction patients? This question was analysed by means of a follow-up study on men between 1986 and 1992 (group 1: n = 64, age = 46.6 (+/- 5.4), 5-6 years follow-up; group 2: n = 36, age = 51.2 (+/- 7.5), 2 years follow up), all of whom underwent a cardiac rehabilitation program in our hospital. Our aim was to determine the predictive power of social and psychological as compared to cardiologic factors. These factors were operating under two relevant conditions: 1. relative social homogeneity of the samples; 2. rehabilitation including qualified cardiologic diagnostic and an interdisciplinary therapeutic program. As a result we found age--at the same time a biologic and a social variable--to be the best independent predictor in logistic regression as in discriminant analysis. Age was followed by hopelessness in the year before MI, ST segment depression in physical stress test and, with restriction, marital status. Thus our study points to three factors limiting employment status: age as a biological and social limit for achievement, ST segment depression as a coronary and ongoing hopelessness as a psychological limit, with a social background of living alone in some cases. It is important for cardiac rehabilitation to take into account not only biological but also social and psychological limits of work capacity. Comprehensive care tries to modify these limits but cannot remove them.     

Neuromuscular disorders associated with failure to wean from the ventilator

OBJECTIVE: To determine, by retrospective chart analysis, the frequency, type and significance of neuromuscular disorders in patients whose clinical features suggested a neuromuscular cause of failure to wean. BACKGROUND: Failure to wean is a common and difficult problem in critical care units. While a neuromuscular cause may be suspected in some patients, the frequency and type has not been determined utilizing comprehensive electrophysiological studies of limbs and the respiratory system. Such knowledge may aid in patient management and prognosis. METHODS: The clinical setting was a critical care/trauma centre that admits 1500 patients per year, approximately 500 being on ventilators for longer than five days. We analyzed the hospital charts of 40 patients admitted to the unit during three years, whose respiratory assessment suggested a neuromuscular cause for failure to wean from the ventilator. To investigate this possibility, we performed electrophysiological studies of the limbs and also of the respiratory system by phrenic nerve conduction and needle electromyography of the chest wall and diaphragm. The results were compared to 25 healthy controls. RESULTS: 38 of 40 patients (95%) had a neuromuscular disorder: 25--critical illness polyneuropathy, 2--Guillain-Barré syndrome, 4--diabetic and critical illness polyneuropathy, 2--uremic and critical illness polyneuropathy, 10--an abnormality of central drive, 5--unilateral phrenic nerve palsy, 3--a neuromuscular transmission defect, and 5--a primary myopathy. Fifteen (38%) had a combination of disorders. Patients with more severe polyneuropathy took longer to wean, a mean of 136 versus 52 days (p = 0.007). The severity of the polyneuropathy had no effect on mortality. CONCLUSIONS: Electrophysiological studies of limbs and the respiratory system are together valuable in confirming the presence, and identifying the specific type of neuromuscular cause for difficulty in weaning from the ventilator. This information is important in patient management and prognosis.