下一代通信技术对广播电视业务发展的影响(上)

下一代通信技术的发展会给广播电视业务的发展带来新的契机和挑战.广播电视业务的发展应充分考虑"多播"这一特征,开展多种信息服务,良好的质量和内容将成为广播电视在竞争中的"杀手锏".开发"多功能一体"的智能终端是开展数字广播电视业务的必然趋势和要求.借鉴通信的业务模式,构筑下一代广播网络,主动联合通信网和互联网开展新业务,是广播电视业进一步发展的关键.本文将结合下一代通信技术和广播电视业务的关系,从业务、传输和接入等角度分别进行讨论.     

我国钛白粉厂家将面临同跨国公司在国内市场的竞争

我国钛白粉厂家将面临在国内市场直接同跨国公司的竞争。建议国内钛白粉厂家调整产业结构,加强技术创新,迎接新挑战。     

Inhibition of pink color development in cooked, uncured ground turkey through the binding of non-pink generating ligands to muscle pigments

The pink color defect in cooked, uncured turkey is a sporadic problem that can result in economic loss and consumer dissatisfaction. Fourteen ligands were tested in ground turkey samples for their ability to reduce pink color development in control samples and in the presence of 150 ppm sodium nitrite or 1.0% nicotinamide (pink color producing agents). The 14 ligands evaluated were: 3-amino pyridine (AP), 4-benzoylpyridine (BP), diethylenetriamine pentaacetic acid (DA), ethylenedinitrilo-tetraacetic acid disodium salt (EA), 2,3 dihydroxybenzoic acid (DB), 3-ethyl pyridine (EP), trans 1,2-diaminocyclohexane-N,N,N',N' tetraacetic acid monohydrate (HA), calcium reduced nonfat dried milk (NM), 2,3 phthalic acid (PA), 3-picoline (PC), pyrrole (PY), pyridazine (PZ), pyridinedicarboxcylic acid (YA), and pyrazinedicarboxcylic acid (ZA). All ligands were incorporated into ground turkey at 0.20 mg/g (meat weight basis) except for NM (30 mg/g). Color was evaluated using a reflectance spectrophotometer to measure pigment changes (nicotinamide hemochrome, nitrosohemochrome) and with a chroma meter to determine CIE L* a* b* values. Reduction in pink color development was apparent with the addition of the ligand alone and in the presence of sodium nitrite and especially nicotinamide. The four most effective ligands tested were DA, EA, HA, and NM. In general, pink color reduction was highest in the ligand only and the ligand plus nicotinamide samples as was observed by CIE a* and nicotinamide hemochrome value reductions.     

A 5-year evaluation of ceramic inlays (CEREC)

BACKGROUND: The aim of this study was to evaluate the morbidity and mortality attributable to smoking. MATERIAL AND METHODS: A transversal study was performed in a reference population of residents of the province of Granada (Spain). The number of deaths in 1985, the number of patients admitted to public hospitals in 1987 and a sample of out patients in 1989 were gathered from the National Institute of Statistics and hospital registries, and a prospective collection from out patient clinics was also carried out. The diseases studied included: oropharyngeal, esophageal, pancreatic, laryngeal, lung, bladder and kidney carcinomas, ischemic cardiopathy, cerebrovascular stroke, peripheral arteriopathy and chronic obstructive lung disease (COPD). Statistical analysis was performed by populational etiologic fraction and the chi square test. RESULTS: Four point five percent of the total number of annual hospital admissions, 6.3% of the out patients, 15.9% of the mortality and 12.0% of the total number of potential years of life lost (TPYLL) were estimated to be attributable to smoking in individuals over the age of 15 years in the province of Granada. The most frequent causes of morbidity attributable to smoking were COPD and ischemic cardiopathy, and with regards to mortality, ischemic cardiopathy (28.5%), COPD (21.6%) and lung cancer (17.5%). Higher percentages were observed in males than in females and in the group from 46 to 65 years of age. CONCLUSIONS: Smoking is not only responsible for an important percentage of deaths, but also leads to premature death and a reduction in the quality of life which is translated into an excess of health care costs. Since the impact of smoking becomes particularly evident from 46 to 65 years of age, smoking prevention should be centered on the early years of life.     

MICROFILTRATION of CHICKEN PROCESS WATERS FOR REUSE: PLANT STUDIES and PROJECTED OPERATING COSTS1

Commercial scale ceramic microfilters were used in plant tests to determine flux rate and operating parameters for waters from a poultry scalder, a poultry chiller, and brine from a delicatessen products chiller, under commercial conditions. Filtration produced clear permeate from all waters. Microorganism counts were essentially reduced to zero in scalder and chiller water permeates, with BOD reduced by about 70% in scalder water permeate and about 60% in chiller water permeate. Flux rates were in the range of 224-204 L/m²h for scalder water at 54°C and 114-81 L/m²h for chiller water at ambient temperature. Test results were used to project nonlabor operating savings and/or costs resulting from the use of microfiltration to recondition and reuse bath overflow. For a processing rate of 140 birds/min and bath size of 37,850 L (10,000 gal), an annual savings of $21,000-$26,000 were estimated for scalder water filtration, while annual costs of $65,000-$84,000 were estimated for chiller water filtration. For a deli brine bath size of 1,170 L (300 gal), annual costs of about $700 were estimated. Retentate heating and electrical usage associated with centrifugal filter pumps were projected as predominant cost factors. Besides costs, other factors such as nonchemical control of microbial growth, water savings, and reduced discharge levels may also be important reasons for considering microfiltration.     

Molecular cloning of the murine IL-1 beta converting enzyme cDNA

IL-1 beta is a potent modulator of immune and inflammatory responses. Murine IL-1 beta is initially synthesized as an inactive 33-kDa pro-molecule that is activated by proteolytic cleavage between Asp-117 and Val-118 to generate the 17-kDa mature IL-1 beta protein. This cleavage is catalyzed by a specific protease that has been designated the IL-1 beta converting enzyme (or IL-1 beta convertase). We have used a human IL-1 beta convertase cDNA to isolate murine convertase cDNA from a WEHI-3 library. These cDNA predicted that the murine convertase is a 402-residue protein. Overall, the murine convertase showed 71% nucleotide and 62% predicted amino acid sequence identity with the human convertase. Southern blot analysis of interspecific backcross mice indicated that the murine IL-1 beta convertase is encoded by a single copy gene located on murine chromosome 9. The murine convertase showed broad constitutive expression, being detected in mononuclear phagocyte and T lymphocyte cell lines as well as in spleen, heart, brain, and adrenal glands. The expression of the murine convertase in mononuclear phagocytes was up-regulated by treatment with LPS or rIFN-gamma. These studies establish that the IL-1 beta convertase is an evolutionarily conserved, widely expressed enzyme that can be regulated at a pretranslational level.     

NUMERICAL STUDY FOR EVOLUTION OF COHERENT VORTEX IN UNIDIRECTIONAL OSCILLATORY BOUNDARY LAYER OVER SAND RIPPLES

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