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21.
QoS online routing and MPLS multilevel protection: a survey   总被引:3,自引:0,他引:3  
A survey of MPLS protection methods and their utilization in combination with online routing methods is presented in this article. Usually, fault management methods pre-establish backup paths to recover traffic after a failure. In addition, MPLS allows the creation of different backup types, and hence MPLS is a suitable method to support traffic-engineered networks. In this article, an introduction of several label switch path backup types and their pros and cons are pointed out. The creation of an LSP involves a routing phase, which should include QoS aspects. In a similar way, to achieve a reliable network the LSP backups must also be routed by a QoS routing method. When LSP creation requests arrive one by one (a dynamic network scenario), online routing methods are applied. The relationship between MPLS fault management and QoS online routing methods is unavoidable, in particular during the creation of LSP backups. Both aspects are discussed in this article. Several ideas on how these actual technologies could be applied together are presented and compared.  相似文献   
22.
Colombia has the third greatest biodiversity in the world and many plants have yet to be studied. Laurel wax is obtained from the fruit of Myrica pubescens , a small tree that can be found in some rural zones in the Nariño department. The main objective of this investigation is to contribute to the development of sustainability of the communities that produce laurel wax in Colombia by proposing possible uses in personal care products. This work involves: 1. Determining the physicochemical properties of wax obtained from the fruit of Myrica pubescens , which is known in the region as laurel wax, 2. Proposing applications and uses of this wax in personal care products on the basis of the results of comparative stability and sensory studies with other natural waxes. 3. Performing a safety evaluation using the Het-Cam test and thereby avoiding animal experiments. Emulsions and color cosmetics can be developed with laurel wax. Replacement of beeswax with laurel wax in lipsticks was studied using analytical sensory techniques with the help of a trained panel; this change improved the slipperiness and uniformity. According to a safety evaluation based on the Het-Cam test, laurel wax should not be an irritant in vivo .  相似文献   
23.
Insulin receptor (IR) gene expression at the mRNA level was investigated in hindlimb skeletal muscle, epididymal adipose tissue and in the liver of rats exposed to prolonged in vivo administration of deoxycorticosterone acetate (DOCA). Following treatment, plasma insulin levels were reduced while glucose levels increased compared to values in control rats. DOCA-treated animals showed an increase in blood pressure and a reduction in body weight. This treatment also induced hypokalemia and decreased plasma protein levels. Sodium levels were unaffected. Moreover, no differences in DNA and protein content or in the indicator of cell size (protein/DNA) were observed in the skeletal muscle or adipose tissue of animals. In contrast, there was a clear increase in the protein and DNA contents of the liver with no change in the indicator of cell size. Northern blot assays revealed 2 major IR mRNA species of approximately 9.5 and 7.5 Kb in the 3 tissues from control animals. DOCA treatment induced no change in the levels of either RNA species in skeletal muscle. However, a decrease of approximately 22% was detected in the levels of both species in adipose tissue whereas the liver showed an increase of 64%. These results provide the first evidence for an in vivo tissue-specific modulation of IR mRNA levels under experimental conditions of mineralocorticoid excess.  相似文献   
24.
The separate cellular regions of the reptilian cerebral cortex were studied using Numerical Taxonomy. Three parameters were employed: a) The area occupied by each region at the several levels studied. b) The total area of the cell nuclei present in each level. c) The average are of these nuclei. Numerical Taxonomy resolves the problem by means of a dendrogram which represents the normalised distances, which indicate levels of similarity on absciassas. The elements studies are on the ordinate axis. The dendrogram shows the different levels of similarity existing between each one of the chosen populations. Depending upon the degree of similarity one may deduce the similarities or differences existing between these populations, and also the characteristics of each cellular population throughout the length of its presence in the cerebral cortex and the variations between the regions. These results, in the first place, relate to the four cortical regions: medialis cortex, dorsomedialis cortex, dorsalis cortex, and lateralis cortex, and in the second place, to each one of the regions within the entire telencephalic cortex.  相似文献   
25.
Lymphangioleiomyomatosis (LAM) is a rare lung disease that mainly affects women of childbearing age. Pulmonary disease that is indistinguishable from LAM appears in 1% of patients with tuberous sclerosis (TS). At present we can not say whether we are looking at an association of two rare diseases or at a single disease with different clinical profiles. To date, open lung biopsy has been required for definitive diagnosis. We report the case of a women with TS and LAM in whom a diagnosis of pulmonary involvement was based on clinical signs and high resolution computerized tomography of the chest.  相似文献   
26.
Thiocoraline is a thiodepsipeptide antitumor compound produced by two actinomycetes Micromonospora sp. ACM2-092 and Micromonospora sp. ML1, isolated from two marine invertebrates (a soft coral and a mollusc) found of the Indian Ocean coast of Mozambique. By using oligoprimers derived from nonribosomal peptide synthetase (NRPS) consensus sequences, six PCR fragments containing putative NRPS adenylation domains were amplified from the chromosome of Micromonospora sp. ML1. Insertional inactivation of each adenylation domain showed that two of them generated nonproducing mutants, thereby indicating that these domains were involved in thiocoraline biosynthesis. Sequencing of a 64.6 kbp DNA region revealed the presence of 36 complete open reading frames (ORFs) and two incomplete ones. Heterologous expression of a region of about 53 kbp, containing 26 of the ORFs, in Streptomyces albus and S. lividans led to the production of thiocoraline in these streptomycetes. Surprisingly, the identified gene cluster contains more NRPS modules than expected on the basis of the number of amino acids of thiocoraline. TioR and TioS would most probably constitute the NRPS involved in the biosynthesis of the thiocoraline backbone, according to the colinearity of the respective modules. It is proposed that two other NRPSs, TioY and TioZ, could be responsible for the biosynthesis of a small peptide molecule which could be involved in regulation of the biosynthesis of thicoraline in Micromonospora sp. ML1. In addition, a pathway is proposed for the biosynthesis of the unusual starter unit, 3-hydroxy-quinaldic acid.  相似文献   
27.
The development of transparent flexible dust shields using both single- and three-phase electrodynamic shields is reported here for possible application on Mars and Earth to minimize obscuration of solar panels from the deposition of dust. The electrodynamic screens (EDS) are made of transparent plastic sheets, such as polyethylene terephthalate (PET) for its UV radiation resistance, and a set of parallel conducting electrodes made of transparent indium tin oxide (ITO) embedded under a thin transparent film. The basic principle of EDS operation, a simplified mathematical model of particle trajectories, the experimental setup used for testing the screens, and their dust removal efficiencies (DRE) are described. Results of our measurements on dust removal efficiency of EDS as a function of the particle size and electrostatic charge distributions of Mars simulant dust are reported. The results show that the EDS technology has a strong potential for protecting solar panels against dust hazards with DRE higher than 80% for dust. The power requirements will be approximately 10 watts per square meter of the panels when cleaning is needed.  相似文献   
28.
To assess emissions of dioxins (chlorinated dibenzodioxins and dibenzofurans) and PCB from uncontrolled domestic combustion of waste ("backyard burning"), test combustions in barrels and open fires were monitored. The waste fuels used were garden waste, paper, paper and plastic packaging, refuse-derived fuel (RDF), PVC, and electronic scrap. Combustions including PVC and electronic scrap emitted several orders of magnitude more dioxins than the other waste fuels. Emissions from the other fuels had considerable variations, but the levels were difficult to relate to waste composition. Emission factors of PCDD/F and PCB from the backyard burning ranged from 2.2 to 13 000 ng (WHO-TEQ)/kg. The levels found in ash usually were less than 5% of the total. For assessment of total emissions of dioxins and PCB from backyard burning of low and moderately contaminated wastes, an emission factor range of 4-72 ng (WHO-TEQ)/kg is suggested. These figures implythat combusting waste in the backyard could contribute substantially to total emissions, even if the amounts of fuel involved are equivalent to just a few tenths of a percent of the amounts combusted in municipal waste incinerators.  相似文献   
29.

Background

Although several epidemiological studies have examined the mortality among users of spit tobacco, none have compared mortality of former cigarette smokers who substitute spit tobacco for cigarette smoking (“switchers”) and smokers who quit using tobacco entirely.

Methods

A cohort of 116 395 men were identified as switchers (n = 4443) or cigarette smokers who quit using tobacco entirely (n = 111 952) when enrolled in the ongoing US American Cancer Society Cancer Prevention Study II. From 1982 to 31 December 2002, 44 374 of these men died. The mortality hazard ratios (HR) of tobacco‐related diseases, including lung cancer, coronary heart disease, stroke and chronic obstructive pulmonary disease, were estimated using Cox proportional hazards regression modelling adjusted for age and other demographic variables, as well as variables associated with smoking history, including number of years smoked, number of cigarettes smoked and age at quitting.

Results

After 20 years of follow‐up, switchers had a higher rate of death from any cause (HR 1.08, 95% confidence interval (CI) 1.01 to 1.15), lung cancer (HR 1.46, 95% CI 1.24 to 1.73), coronary heart disease (HR 1.13, 95% CI 1.00 to 1.29) and stroke (HR 1.24, 95% CI 1.01 to 1.53) than those who quit using tobacco entirely.

Conclusion

The risks of dying from major tobacco‐related diseases were higher among former cigarette smokers who switched to spit tobacco after they stopped smoking than among those who quit using tobacco entirely.Several epidemiological studies have examined morbidity and mortality among users of spit tobacco (spit‐tobacco users),1,2 but none have compared the mortality of former cigarette smokers who substitute spit tobacco for cigarette smoking (“switchers”) to those of smokers who quit using tobacco entirely. Comprehensive reviews by the US Surgeon General,3 and the International Agency for Research on Cancer4 and others5 have concluded that evidence is sufficient that the use of spit tobacco causes several types of cancer in humans. Although the evidence linking use of spit tobacco to increased risk of cardiovascular diseases is limited,6 these products cause acute increases in heart rate and blood pressure, as well as long‐term adverse effects on blood pressure and lipid profiles.7We compared mortality of switchers to those of former cigarette smokers who quit using tobacco entirely among men enrolled in a large prospective cohort.  相似文献   
30.
Although the European rabbit is an “endangered” species and a notorious biological model, the analysis and comparative characterization of new tissue sources of rabbit mesenchymal stem cells (rMSCs) have not been well addressed. Here, we report for the first time the isolation and characterization of rMSCs derived from an animal belonging to a natural rabbit population within the native region of the species. New rMSC lines were isolated from different tissues: oral mucosa (rOM-MSC), dermal skin (rDS-MSC), subcutaneous adipose tissue (rSCA-MSC), ovarian adipose tissue (rOA-MSC), oviduct (rO-MSC), and mammary gland (rMG-MSC). The six rMSC lines showed plastic adhesion with fibroblast-like morphology and were all shown to be positive for CD44 and CD29 expression (characteristic markers of MSCs), and negative for CD34 or CD45 expression. In terms of pluripotency features, all rMSC lines expressed NANOG, OCT4, and SOX2. Furthermore, all rMSC lines cultured under osteogenic, chondrogenic, and adipogenic conditions showed differentiation capacity. In conclusion, this study describes the isolation and characterization of new rabbit cell lines from different tissue origins, with a clear mesenchymal pattern. We show that rMSC do not exhibit differences in terms of morphological features, expression of the cell surface, and intracellular markers of pluripotency and in vitro differentiation capacities, attributable to their tissue of origin.  相似文献   
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