The Incidental, Accidental Deregulation of Data ... and Everything Else

Existing regulatory codes for telephone, cable and broadcasttreat ‘data’ services as largely beneath ot outsideofficial attention. ‘Enhanced servuces’ have beenexclided from the ambit of ‘basic’, regulated telephony.They are exempt from access charges and almost completely freeof most other forms of common-carrier regulation. Data servicesprovided over mobile radio, cable, terrestrial broadcast andDirect Broadcasting Satellite likewise are excused from mostforms of rate, content and carriage regulation. Data has longbeen the ‘incidental’ service tagged onto somethingelse order and more important. As such, data has been the fotunatebeneficiary of regulatory accident, inattention, neglect andindifference. Wires and radios alike will all soon be digital,and bandwidth is increasing rapidly in every medium. ‘Data’traffic is growing far faster than analog voice or video. Andon broadband digital channels ‘data’ encompasseseverything. The data inmates ate taking over the regulatoryasylum.     

PLASMIDS IN CLOSTRIDIUM PERFRINGENS

A review of plasmids in Clostridium perfringens is presented. The characterization of the caseinase mediating plasmid pHB101 based upon limited DNase treatment, restriction endonuclease treatment, and agarose gel electrophoresis is described. Antibiotic profiles for the wild type strain and the cured strain were determined. The plasmid pHB101 was non self-transferable. The curing procedure resulted in a stable morphological change from rod to coccoid or bacillary-coccoid shape. A screening of C. perfringens strains showed the general presence of a 9.4 Mdal plasmid which may have been overlooked in the past due to chromosomal DNA masking effects.     

Structural Changes Related to Texture of Pre-Peeled Potatoes

Pre-peeled potatoes, treated with heated ascorbic/citric acid solutions to control browning, undergo firming and separation of superficial tissues that affect texture after mashing and slicing following cooking. Examination of superficial parenchyma cells in cooked potatoes by scanning and transmission electron microscopy indicated greater cell wall rigidity and middle lamella retention in samples treated with browning inhibitors than in untreated controls. Lumps in mashed potatoes prepared from treated samples showed similar characteristics. Treated samples sometimes displayed a discontinuity beneath the superficial tissue, corresponding to site of tissue separation during slicing. These observations are consistent with treatment-induced changes in cell wall and/or middle lamella pectins as the cause of such textural defects.     

Kinetics of sunflower oil contamination with polycyclic aromatic hydrocarbons from contaminated recycled low density polyethylene film

The possibility of food contamination with polycyclic aromatic hydrocarbons (PAHs) by rediffusion from polyethylene film made of contaminated recycled polyethylene (PE) was tested. PE was contaminated with PAHs by diffusion from water medium spiked with fluoranthene (FI), pyrene (Py), and benzo(a)pyrene (BaP). The PE was recycled by heating at 150°C for 10 min. The recycling process did not affect the PAH concentration in PE. From the recycled PE, a PE film was made and rediffusion of PAHs from the PE film into a sunflower oil was followed for 600 h at 24°C. Diffusion of PAHs into the oil demonstrated the potential of PAH-contaminated PE as a source of contamination of food. The PAH concentration in vegetable oil was linearly dependent on the square root of the storage time. A kinetic equation for PAH rediffusion from PE film into the oil is proposed.     

Hydrolytic Stability at Intermediate pHs of the Common Purine Nucleotides in Food, Inosine-5'-monophosphate, Guanosine-5'-monophosphate and Adenosine-5'-monophosphate

When the purine nucleotides, inosine-5′-monophosphate (IMP), guanosine-5′-monophosphate (GMP) and adenosine-5′-monophosphate (AMP) were subjected to canning temperatures (121°C) at pHs between 3 and 8, extensive phosphate bond hydrolysis to the corresponding nucleoside occurred. The half life for hydrolysis at pH 5 was 63, 41, and 51 min for IMP, GMP, and AMP, respectively. Rates of hydrolysis were even greater at pH 3 because both hydrolysis of the phosphate bond and the glycosidic bond occurred simultaneously. An Arrhenius plot of data collected at different temperatures illustrated that the nucleotides were very stable at room temperature. Half lives for IMP, GMP, and AMP were estimated to be 36, 19, and 40 yr, respectively, at 23°C and a pH of 5.     

Non-isothermal Kinetics of Benzo[a]Pyrene Photooxidation in Glyceryl Trioctanoate

Benzo[a]pyrene (BaP) was dissolved in glyceryl trioctanoate, heated in a glass reaction vessel within temperature range 297.95–361.85 K with heating rate of 1 K/min and simultaneously exposed to UV light at wavelength λ = 365 nm at radiation power 20 mW cm^?2 in order to study the decrease of BaP concentration due to its photooxidation. The concentration of BaP was determined by HPLC-FD periodically in 5 min intervals. As observed, the BaP concentration decreased from 62.2 μg L^-1 to 19.8 μg L^-1. From the experimental results, the parameters characterizing the non-isothermal kinetics of BaP photooxidation have been obtained. The parameters were tested at two various isothermal conditions (290.16 and 323.26 K) to verify a suitability of derived parameters. Comparing calculated and measured data of half-lives of BaP decrease at mentioned temperatures it was found that calculated half-lives are in a good accordance with those experimentally obtained values, when relative standard deviations at 290.16 K were 17.0% and 5.4% at 323.26 K, respectively. The kinetic parameters enable the calculation of the rate constant for any temperature in isothermal regime and make possible to model, in general, the kinetics of such processes without a deeper insight into their mechanisms.     

ON THE CHEMICAL OSCILLATIONS IN DIFFERENTIAL REACTORS: A CASE STUDY OF AMMONIA OXIDATION ON PLATINUM

Trying to identify the mechanism(s) responsible for isothermal oscillatory behavior of heterogeneous catalytic reaction systems, many investigators have assumed low conversions with respect to the limiting reactant(s) so that the bulk phase concentrations of the reactants may be considered constant. In this study, it is shown that even in a differential catalytic CSTR, in which conversion of the reactants may be less than %, the changes of the gas phase concentrations of the reacting.species may play a key role in the overall dynamic behavior of a reaction system; for instance, they may drive the oscillations observed. The reduction of nitric oxide by ammonia on polycrystalline platinum is discussed in detail within this context. Several other oxidation reactions are also discussed