Bacterial contamination in an egg-breaking factory and its control

From January to November, 2003, bacterial contamination was surveyed in a small egg-breaking factory that produced non pasteurized liquid egg. Test egg samples were taken at various stages of the egg processing operation. Salmonella Enteritidis was isolated from liquid egg yolk and liquid egg white on October, but was not found in any other samples (50 liquid egg samples, 21 containers and 94 attached production facilities and gloves). The data suggest that the contamination rate (3.8%) is lower than those reported previously. Levels of bacterial standard plate counts, gram-positive bacterial counts and gram-negative bacterial counts were in the ranges of 2 to 5 log CFU/g, 2 to 3 log CFU/g, 2 to 5 log CFU/g, respectively. Liquid egg containers returned from customers was contaminated with bacteria at the level of 8 log CFU per container. However, washing and application of a sanitizer containing sodium hypochlorite reduced the bacterial counts.     

Effect of diacylglycerol on the development of impaired glucose tolerance in sucrose-fed rats

The effects of DAG oil and TAG oil on impaired glucose tolerance in rats that were fed a diet containing high levels of sucrose were compared. Male Wistar rats (8 wk old and 32 wk old) were fed either high-sucrose (57.5% sucrose w/w) or control diets containing either 10% (w/w) DAG or TAG oil with a similar FA composition for 48 wk in 8-wk-old rats and for 24 wk in 32-wk-old rats. Plasma lipids, the size of the islets of Langerhans, and insulin, glucose, and adipocytokine levels were measured. An oral glucose tolerance test (OGTT) was carried out during the study period. For rats in both age groups that were fed a high-sucrose diet, the DAG oil group had lower plasma glucose and insulin response in an OGTT, and lower homeostasis model assessment-R levels, than the TAG oil group. Furthermore, in 8-wk-old rats that were fed a high-sucrose diet, the DAG oil group accumulated less visceral fat and showed decreases of plasma adiponectin and suppressed increases of plasma insulin, leptin, and the size of islet of Langerhans compared with the TAG oil group. No difference in the OGTT was found between the DAG and TAG oil groups in either age group of rats fed a control diet. In conclusion, these results suggest that DAG oil ingestion prevents the high-sucrose-diet-induced development of impaired glucose tolerance compared with TAG oil ingestion.     

Isolation and characterization of murine hepatocytes following collagenase infusion into left ventricle of heart

A method for obtaining mouse hepatocytes by infusing collagenase solution into the left ventricle was established. This technique was shown to be equivalent to the intra-portal infusion method and more practical, especially in postnatal mice with a small body size.     

Estimation of order and delay time of the process in a closed-loop control system

This paper proposes a procedure for estimating the order and delay time of the process in a closed-loop control system from its input and output data. There are identifiability conditions that assure uniqueness and unbiasedness of the estimates, but they assume that the order and delay time of the process are known. Therefore, it is of primary importance to estimate the order and delay time of the process in the identification of a closed-loop system. In this paper, the authors first investigate the influence of the closed loop on identification, then propose a procedure for estimating the order and delay time, taking into account their consequences. © 1997 Scripta Technica, Inc. Electr Eng Jpn, 121(2): 63–71, 1997     

Chromosomal DNA patterns and gene stability of Pichia pastoris

We have clearly resolved four chromosomal bands from four Pichia pastoris (Komagataella pastoris) strains by using contour-clamped homogeneous electric field gel electrophoresis. The size of the P. pastoris chromosomal bands ranged from 1·7 Mb to 3·5 Mb and total genome size was estimated to be 9·5 Mb to 9·8 Mb; however, chromosome-length polymorphisms existed among four strains. Thirteen cloned genes isolated from strain GTS115 were assigned to the separated chromosomes, revealing that different hybridization patterns were observed in the AOX2 and URA3 genes among strains. P. pastoris is frequently used as an efficient host for heterologous gene expressions. We analysed chromosomal stability of strain GTS115-derived recombinant cell expressing human serum albumin during serial cultivation under the condition of vegetative and non-selective growth. No chromosomal rearrangements were observed and the expression constructs integrated into the his4 locus on chromosome I were very stable even at 83 generations, suggesting that stable expression would be carried out even in large-scale fermentation. © 1998 John Wiley & Sons, Ltd.     

Observation of electron field emission patterns from B-doped diamond films

To develop electron beam sources of carbon materials, field emission patterns were observed in three different setups. The first was a diode-type, in which a carbon specimen was facing to a positively biased fluorescence plate. The second was a triode-type, in which a positively biased grid was placed between them. In the third setup, a commercial electron gun was modified so that it could accommodate a carbon specimen and a grid. A fluorescence plate was placed in a vacuum chamber outside the gun. As the carbon specimen for electron emission source, B-doped diamond films, a single crystal diamond with a B-doped layer, an undoped diamond film and a glass-like carbon both with a fibrous structure at the surface, and a sponge carbon were used. It was found that electron emission from edges was dominant for 1×1 cm diamond films and carbon specimens in the diode-type setup. In the triode-type setup, the edges of the specimens were masked with a Kapton® tape. The electron emission occurred only from some spots on the specimen. In the electron gun setup, it was confirmed that an electron beam was generated, and a fairly uniform circle was seen on the fluorescence plate under defocused situation, while the circle became smaller by adjusting the current of the focusing lens. Although more uniform emission from the electron source materials seemed to be necessary for practical applications, it was demonstrated that an electron beam could be generated even in such a simple setup.     

Dynamics of antioxidant action of vitamin E

Vitamin E is the major lipophilic, radical-scavenging antioxidant in vivo and protects humans from the oxidative stress mediated by active oxygen and nitrogen species. The mechanisms of the inhibition of oxidation by vitamin E in vitro are now fairly well understood, but the dynamics of antioxidant action of vitamin E in vivo have not been well elucidated yet, primarily because of the inherent heterogeneity of biological systems. In this Account, the factors which determine the antioxidant capacity of vitamin E are discussed, and the importance of its localization and mobility in the membranes and lipoproteins is emphasized.     

Bacterial community structures in MBRs treating municipal wastewater: relationship between community stability and reactor performance

Bacterial community structures in pilot-scale conventional membrane bioreactors (CMBRs) and hybrid MBRs (HMBRs) which were combined with pre-coagulation/sedimentation were analyzed by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) and fluorescence in situ hybridization (FISH) techniques. The results were compared with the community structure in a full-scale activated sludge (AS) process treating the same municipal wastewater. The Dice index (Cs) of similarity analysis of DGGE banding patterns demonstrated that the microbial community in AS was more similar to those in CMBR1 and CMBR2 than HMBR1 and HMBR2. This suggested that influent wastewater composition had a larger impact on bacterial community structures. Long-term community structure changes in the HMBRs and CMBRs were monitored and analyzed over 240 days by Non-metric multidimensional scaling (NMDS) analysis of DGGE banding patterns. The NMDS analysis revealed that both HMBRs and CMBRs had marked changes in community structures during the first about 100 days. Thereafter the perpetual fluctuations of bacterial community structures were observed in both HMBRs and CMBRs, even though the stable MBR performances (the performance was measured as membrane permeability and removal of dissolved organic carbon, DOC) were achieved. These results suggest that not only the stability, but also the adequate dynamics ("flexibility") of the bacterial community structure are important for the stable performance of the MBRs treating complex municipal wastewater.     

Development of stone tool use by wild chimpanzees (Pan troglodytes).

At the age of 3.5 years, wild chimpanzees at Bossou, Guinea, begin to use hammer and anvil stones to crack oil-palm nuts to get the kernels. To clarify the developmental processes, the authors did a field experiment in which stones and oil-palm nuts were provided. Infant chimpanzees' stone–nut manipulation was observed and video recorded. Data were collected from 3 infants younger than 4 years old from 1992 to 1995. The authors analyzed 692 episodes of infants' stone–nut manipulation and 150 episodes of infants' observation of nut cracking performed by adults. Infants observed other chimpanzees' nut cracking and got the kernels from them. The stone–nut manipulation developed from a single action on a single object to multiple actions on multiple objects. Although infant chimpanzees at the age of 2.5 years already acquired basic actions necessary for nut cracking, they did not combine the actions in an appropriate sequence to perform actual nut cracking. (PsycINFO Database Record (c) 2010 APA, all rights reserved)