Effects of Storage Time and Temperature on the Microflora and Amine-Development in Spanish Mackerel (Scomberomorus maculatus)

Microbial content was characterized and levels of three amines (histamine, cadaverine, and putrescine) were determined in Spanish mackerel (Scomberomorus maculatus) decomposed at PC, WC, and 30°C for varying lengths of time. Correlations were shown (1) between the levels of the histamine, cadaverine, and putrescine and the time and temperature of decomposition, (2) between the ratios of cadaverine/histamine and putrescine/histamine levels and the temperature of decomposition, and (3) between increasing total microbial counts and rising amine levels. A total of 14 bacterial species with histidine decarboxylase activity were isolated from decomposing fish, including three species (Acinetobacter lwoffi, Pseudomonas putrefaciens, and Aeromonas hydrophila) not previously reported to have the potential to produce histamine.     

Oxygen Requirements of Bacillus licheniformis and Bacillus subtilis in Tomato Juice; Ability to Grow in Aseptic Packages

Tomato juice was inoculated with spores of Bacillus subtilis and Bacillus licheniformis, placed in jars sealed with four polymers: oriented polypropylene (OPP), low density polypropylene with 4.5% ethyl vinyl acetate (LDPE + EVA), polyvinylidene chloride (PVDC), and polyethylene teraphthalate (PET); used in aseptic packages, serving as lids, heated in a boiling water bath for 10 min, and incubated at 35°C for up to 100 days. B. subtilis and-B. licheniformis grew at the surface of the food when OPP and LDPE + EVA were used, which caused the pH to rise above 4.6 in 60 days and above 5.0 within 100 days. The oxygen partial pressures were 0.20 and 0.18 atm per day, and the oxygen permeation ratios were 5.64 and 0.76 cc/day for LDPE + EVA and OPP, respectively.     

EFFECTS OF CYCLOPROPENOID FATTY ACIDS (BAOBAB SEED OIL) ON THE FATTY ACID PROFILE OF LIPIDS FROM DIFFERENT TISSUES IN THE RAT

Rats were fed for 8 weeks a diet containing either Baobab seed oil (FBO) rich in cyclopropenoid fatty acids (CPFA) or heated oil (HBO) devoid of CPFA. In FBO rats, compared to controls (CO), the monounsaturated fatty acid content of adipose tissue lipids, liver triacylglycerols, liver and adrenal cholesteryl esters and liver, kidney, adrenal phospholipids were highly decreased to the benefit of saturated fatty acid content. In cholesteryl esters and phospholipids, the arachidonic acid (20:4 n-6) content was markedly decreased, especially in adrenals. In adrenal cholesteryl esters, adrenic acid (22:4 n-6) content was decreased more than its precursor. The effects of HBO on the tissue lipid fatty acid profile were practically absent. It is concluded that inhibition of fatty acid desaturation by CPFA previously demonstrated in vitro , was reflected in vivo in tissue lipid fatty acid composition.     

功能后设计

女主人SUE,自从上个世纪70年代,就搬进了位这间于美国旧金山市中心的老宅,那时,这个地区的房屋曾被作为廉价之所,租住着大批波希米亚的年轻艺术家以及学生们,但随着岁月变迁,这片区域成为了炙手可热的黄金地段且房价不菲。SUE于近年开始计划整修房屋,没想到丈夫却突然辞世,无     

BACTERIAL ADHERENCE AND VIABILITY ON CUTTING BOARD SURFACES

The adherence and viability of Escherichia coli inoculated onto the surfaces of plastic cutting boards and new and used wood cutting boards were evaluated. Most of the inoculum was recovered from all surfaces after resident drying times of 5 min and from plastic surfaces at 24 h. When the exposure time was extended to 2 h, > 90% of the cells placed on new and used dry wood surfaces were not recovered after vigorous rinsing. Scanning electron microscopy showed that the bacteria resided within the structural xylem fibers and vegetative elements of the wood. After resident drying times of up to 2 h, almost 75% of the adherent bacteria on the wood surfaces were viable, as defined by a nalidixic acid direct viable count procedure. Microcosm studies showed no intrinsic growth-supporting or toxic properties of the cutting board materials. Bacteria that adhered to plastic surfaces were more easily removed by low-temperature washing than were cells that adhered to wood surfaces. These studies demonstrated that bacteria adhering to wood surfaces resided within the structural and vegetative elements of the wood's xylem tissues and were viable; wood was more retentive than plastic; penetration of the inoculum liquid promoted cell adherence to the wood matrix; and conditioning of wood with water before inoculation interfered with bacterial adherence.     

A Recurrent Neural Network that Learns to Count

Parallel distributed processing (PDP) architectures demonstrate a potentially radical alternative to the traditional theories of language processing that are based on serial computational models. However, learning complex structural relationships in temporal data presents a serious challenge to PDP systems. For example, automata theory dictates that processing strings from a context-free language (CFL) requires a stack or counter memory device. While some PDP models have been hand-crafted to emulate such a device, it is not clear how a neural network might develop such a device when learning a CFL. This research employs standard backpropagation training techniques for a recurrent neural network (RNN) in the task of learning to predict the next character in a simple deterministic CFL (DCFL). We show that an RNN can learn to recognize the structure of a simple DCFL. We use dynamical systems theory to identify how network states reflect that structure by building counters in phase space. The work is an empirical investigation which is complementary to theoretical analyses of network capabilities, yet original in its specific configuration of dynamics involved. The application of dynamical systems theory helps us relate the simulation results to theoretical results, and the learning task enables us to highlight some issues for understanding dynamical systems that process language with counters.     

ALKALINE PHOSPHATASE FROM JAW ALA SHRIMP (ACETES INDICUS)

Alkaline phosphatase was isolated from Jawala shrimps (Acetes indicus), a tiny crustacean. The hepatopancreas (head region) is a good source of this enzyme. pH optima of the partial purified enzyme was found to he 9.5 and optimal temperature for maximal activity was 40C. Jawala phosphatase was completely inhibited by 1, 10‐phenanthroline and EDTA, indicating that it is a metalloprotein. The activity of inhibited enzyme was restored by Zn²⁺ and Mn²⁺ salts. Feed back inhibition of the enzyme by inorganic phosphate was also observed.