THE CONTACT HYPOTHESIS IN URBAN CHINA: THE PERSPECTIVE OF MINORITY‐STATUS MIGRANT WORKERS

ABSTRACT: This study is the first to test Allport's (1954) contact hypothesis from the perspective of a minority group in China. Employing a sample of off‐farm migrant workers in urban China, results indicate a positive effect on self‐reported attitudes of intergroup friendship contact between migrant and local workers; and positive effects on self‐reported behavioral interaction between migrants and urban locals of both intergroup friendship and intergroup nonfriendship contact.     

EFFECTS OF BRINING PRETREATMENT AND STORAGE ON CARAMBOLA (AVERRHOA CARAMBOLA L.) PICKLES

Mature, green carambola (Averrhoa carambola L.) were pretreated in 5, 10 or 15% NaCl for 24 h, hot-filled with vinegar, sucrose and spices, and pasteurized at 78 ± 1C for 15 min. No differences (P ≤ 0.05) in appearance, taste and texture were due to prebrining treatments, but most panelists (62%) preferred pickles in 10% brine. This pickle was stored either at 10C or 25C for 8 weeks. Some pickles had sodium benzoate (0.025%) or citric acid (1%) with ascorbic acid (0.25%) in pickling liquor. Interactions of treatments by storage resulted (P ≤ 0.05) in darkening of color, less greenness, more yellowness, softer texture, increase in pH and less than 10 CFU/g microbes in carambola pickles. Carambola slices with ascorbic acid and citric acid were the brightest and most green (P ≤ 0.05) after pickling and remained one of the least dark after storage (P ≤ 0.05). Storage of pickles at 10C minimized quality changes.     

Effect of Radio-Frequency and Low-Frequency Bias Voltage on the Formation of Amorphous Carbon Films Deposited by Plasma Enhanced Chemical Vapor Deposition

The effect of radio-frequency （RF） or low-frequency （LF） bias voltage on the for- mation of amorphous hydrogenated carbon （a-C：H） films was studied on silicon substrates with a low methane （CH4） concentration （2-10 vol.%） in CH4＋Ar mixtures. The bias substrate was applied either by RF （13.56 MHz） or by LF （150 kHz） power supply. The highest hardness values （~18-22 GPa） with lower hydrogen content in the fihns （~20 at.%） deposited at 10 vol.% CH4, was achieved by using the RF bias, However, the films deposited using the LF bias, under similar RF plasma generation power and CH4 concentration （50 W and 10 vol.%, respectively）, displayed lower hardness （~6-12 GPa） with high hydrogen content （~40 at.%）. The structures analyzed by Fourier Transform Infrared （FTIR） and Raman scattering measurements provide an indication of trans-polyacetylene structure formation. However, its excessive formation in the films deposited by the LF bias method is consistent with its higher bonded hydrogen concentration and low level of hardness, as compared to the film prepared by the RF bias method. It was found that the effect of RF bias on the film structure and properties is stronger than the effect of the low-frequency （LF） bias under identical radio-frequency （RF） powered electrode and identical PECVD （plasma enhanced chemical vapor deposition） system configuration.     

EVALUATION OF VARIETAL GRAPE JUICE—INFLUENCE OF PROCESSING METHOD,SUGAR AND ACID ADJUSTMENT,AND CARBONATION1

This study investigated the influence of processing method, sugar and acid adjustment, and carbonation on the quality of grape juice from 5 cultivars of wine grapes. A sensory panel found the juices with adjusted sugar and/or acid rated higher in flavor than the juices with no sugar and/or acid adjustment. Carbonation improved the ratings of the juices with no sugar and/or acid adjustment, but generally had no effect on the adjusted juices. The heat process treatment produced higher color ratings as determined by CDM values in most cultivars. The Riesling and Chelois produced juices that rated comparable to those of Niagara and Concord, the juice industry standards.     

STUDIES of WATER TRANSPORT PHENOMENA DURING POTATO-DRYING

Sorption isotherms and drying mechanisms of Bintje potatoes have been investigated experimentally. the product temperature and the moisture content was determined during the drying experiments. A simulation method to estimate the diffusion coefficient and the moisture content profiles for the potatoes was performed by means of a finite-difference computer program. Experimentally determined moisture contents were compared with calculated for different estimated values of the diffusion coefficient. If the diffusion coefficient was assumed to be 0.8.10^?9 m²/s the correlations were acceptable. the simulated moisture content profiles also gave the surface moisture content. The surface mass transfer coefficient has been calculated, the resulting β values were in the range of 0.014–0.029 m/s.     

Starch gelatinization temperatures within potato during blanching

The progression of gelatinization within potato cylinders blanched at 65,75 and 85°C for 2, 4 and 6 min was followed by iodine staining of sections. The distance to the gelatinization front was measured on photographs of both blanched and stained potatoes. A time-temperature simulation was performed with a finite difference computer program using thermal conductivity, specific heat, phase transition, density, heat-transfer coefficient, and initial temperatures as input data. Measured distances were used to determine the simulated temperature at the gelatinization front. The computer-simulated temperatures used to determine the gelatinization temperature within blanched potato were in good agreement with published values.     

Occurrence and characterization of Staphylococcus aureus isolated from raw milk for cheesemaking

Fifty-four samples of raw milk for cheesemaking were tested for the presence of Staphylococcus aureus . Multiplex polymerase chain reactions were performed to identify presumptive isolates and the presence of enterotoxin-coding genes sea-see . The strains were tested for antibiotic resistance. Eighty strains were identified as S. aureus and 31 of these carried one or more enterotoxin genes ( sea-see ). Resistance to eritromycin, penicillin and ampicillin was widespread among isolates . Staphylococcus aureus in raw milk for cheesemaking may constitute a risk with respect to staphylococcal food poisoning from raw milk products.     

Diffusion in Heated Potato Tissues

Data to optimize nutrient retention during processing of potatoes were obtained by measuring loss of solutes (glucose, fructose, citric acid, potassium, calcium and magnesium) by diffusion into blanch water. Apparent diffusivities were calculated based on Fickian diffusion. Magnesium and calcium did not follow the Fickian approach with the same accuracy as the others. A hindrance factor (K), the ratio of apparent diffusivity in potato to a published value was used. The hindrance factor was calculated at reference temperature 25°C to separate preheating effects from the direct effect of temperature on diffusion coefficients. A mathematical model for K(T,t) was fitted to experimental data for each solute. All solutes showed a sharp decrease of hindrance factor in the region 50–60°C. These models showed, however, that heating of potato affected diffusivities of the solutes to different degrees. Ions had a limit solution retention in the tissue higher than glucose, fructose or citric acid.     

A predictive approach for the generation of rhetorical devices

Human discourse is fraught with rhetorical devices such as contradictions, illustrations, and analogies. These rhetorical devices carry important information which a listener uses to speed up the comprehension process. In this paper, we present a taxonomy of rhetorical devices commonly used in tutoring environment, and model the meaning of a class of rhetorical devices in terms of their anticipated effect on a listener's knowledge. These predictions are then used in planning computer-generated discourse. As a testbed for our ideas, a system called WISHFUL is being implemented to generate commentaries in the domain of high-school algebra within the framework of an intelligent tutoring system.     

Processing of extended shelf life milk using microfiltration

Extended shelf life (ESL) milk was processed with integrated microfiltration (pore size 1.4 µm). The germ-enriched retentate was not used for the final whole milk. Microfiltration led only to a negligible change in the content of the main components of the ESL product compared with the source milk. The total protein was only slightly decreased (0.02–0.03%) and the ratio of the protein fractions was unchanged within the measurement accuracy. The furosine content of the isolated fat globuline membrane fraction could be used as a diagnostic to prove cream had been subjected to high-temperature treatment. The shelf life of the ESL milk was distinctly prolonged compared to HTST-pasteurized milk.