7,483 research outputs found
Chinese children’s causal knowledge and text comprehension
Theme 3: Cognitive and Languagepostprin
A multipath ad hoc routing approach to combat wireless link insecurity
As wireless LAN (WLAN) technologies proliferate, it is becoming common that ad hoc networks, in which mobile devices communicate via temporary links, are built using WLAN products. In the IEEE 802.11b standard, the Wired Equivalent Privacy (WEP) scheme is used as the only measure to enhance data confidentiality against eavesdropping. However, owing to the well known pitfalls in Initialization Vector (IV) attachment in the ciphertext, the underlying 40-bit RC4 encryption mechanism in WEP is unsafe regardless of the key size. On the other hand, solutions involving replacement of RC4 by another cipher are not attractive because that may lead to reconstruction of the whole system and result in high costs as well as redevelopment of the products. In order to enhance the security on the existing development efforts, we propose a novel multipath routing approach to combat the link insecurity problem at a higher protocol layer. This approach does not require the application to use sophisticated encryption technologies that may be too heavy burdens for mobile devices. Based on our suggested confidentiality measurement model, we find that our proposed multipath ad hoc routing technique, called Secure Multipath Source Routing (SMSR), is highly effective.published_or_final_versio
Study of extracellular matrix for the culture of human embryonic stem cells
Poster Session 2: abstract no. 718Background: The development of clinical grade human embryonic stem cells
(hESC) suitable for cell therapy requires defined components for hESC culture.
We hypothesize that the feeder cells used for hESC culture produce extracellular
matrix molecules supporting the growth of hESC. Materials and Methods:
The profiles of mRNA and extracellular matrix production of two human
feeder cell lines, human foreskin fibroblast (hFF-1) and human lung fibroblast
(WI-38) were correlated with their ability to maintain the pluripotency of a
hESC line, BG01V. The mRNA expression profile and matrix production were
determined by Affymetrix microarray chip and liquid chromatography/mass
spectrometry/mass spectrometry analysis, respectively. Results: Using a morphological
grading system, hFF-1 but not WI-38 supported the pluripotency of
BG01V. The observation was supported by over-expression of early differentiation
markers KRT-8 and -18 mRNA in BG01V cells cultured on WI-38, though
the mRNA expression of pluripotent markers Nanog, Oct4 and TRA-1-81
in BG01V cultured with hFF-1 and WI-38 was similar. Microarray analysis
showed that the expression of 530 transcripts was 2-fold higher (P<0.05) in
hFF-1 than in WI-38. The microarray data were validated by real-time PCR on
12 differentially expressed genes related to secretory and extracellular matrix
molecules. Proteomic profiling of the extracellular matrix molecules also
demonstrated differences between the two feeder cell lines. Both microarray
and proteomic analysis identified sulfatase 1 (SUFL1) and chemokine (C-X-C
Motif) ligand 12 (CXCL12) were higher in hFF-1. Conclusion: The difference
in the ability of feeder cells in maintaining the pleuripotency of hESC may be
related to the differential secretion of matrix molecules by the feeder cells.published_or_final_versio
Coefficient of standardized total tract digestibility of phosphorus in oilseed meals and distillers dried grains in growing-finishing pigs
This study was conducted to determine the coefficient of total tract standardized digestibility (CTTSD) of phosphorus (P) in oilseed meals and distillers dried grains (DDG) fed to growing-finishing pigs. Twelve barrows (initial bodyweight (BW) standard deviation, 52.25 +/- 2.57 kg) were allocated individually to metabolism cages. The experimental design was a 12 x 8 incomplete Latin square with 12 dietary treatments and eight replication periods. The diets were formulated individually with dehulled soybean meal produced in Korea (SBM-KD), soybean meal produced in India (SBM-I), soybean meal produced in Korea (SBM-K), corn high-protein distiller dried grains (HPDDGs), tapioca distillers dried grains (TDDG), canola meal (CAM), corn germ meal (CGM), copra meal (CM), palm kernel meal (PKM), sesame meal (SM), perilla meal (PM), and a P-free diet. Intake of P was highest in SM and PM. Excretion of P was reduced in y ascending order as HPDDG, TDDG and CGM; SBM-K; and SM and PM. The CTTAD of P was higher in CGM than SBM-K, TDDG, SM and PM. HPDDG and CGM showed greater CTTSD of P than SBM-K, CAM and PM. Digestible concentration of P on CTTSD (CTTSD-P) of P was greater in PM and CAM than the others except for SBM-KD. In summary, PM could be utilized as an alternative feedstuff to SBM, but its usage is regarded only as a source of P. In addition, the results of the current study would provide valuable information for formulating pig feed with precise P utilization in ingredients using mixed diet
Influence of Rb/Cs cation-exchange on inorganic Sn halide perovskites: From chemical structure to physical properties
CsSnI3 is a potential lead-free inorganic perovskite for solar energy applications due to its nontoxicity and attractive optoelectronic properties. Despite these advantages, photovoltaic cells using CsSnI3 have not been successful to date, in part due to low stability. We demonstrate how gradual substitution of Rb for Cs influences the structural, thermodynamic, and electronic properties on the basis of first-principles density functional theory calculations. By examining the effect of the Rb:Cs ratio, we reveal a correlation between octahedral distortion and band gap, including spin–orbit coupling. We further highlight the cation-induced variation of the ionization potential (work function) and the importance of surface termination for tin-based halide perovskites for engineering high-performance solar cells
Difference in the color stability of direct and indirect resin composites
Indirect resin composites are generally regarded to have better color stability than direct resin composites since they possess higher conversion degree. OBJECTIVE: The present study aimed at comparing the changes in color (ΔE) and color coordinates (ΔL, Δa and Δb) of one direct (Estelite Sigma: 16 shades) and 2 indirect resin composites (BelleGlass NG: 16 shades; Sinfony: 26 shades) after thermocycling. MATERIAL AND METHODS: Resins were packed into a mold and light cured; post-curing was performed on indirect resins. Changes in color and color coordinates of 1-mm-thick specimens were determined after 5,000 cycles of thermocycling on a spectrophotometer. RESULTS: ΔE values were in the range of 0.3 to 1.2 units for direct resins, and 0.3 to 1.5 units for indirect resins, which were clinically acceptable (Δ
A List Scheduling Heuristic with New Node Priorities and Critical Child Technique for Task Scheduling with Communication Contention
Task scheduling is becoming an important aspect for parallel programming of modern embedded systems. In this chapter, the application to be scheduled is modeled as a Directed Acyclic Graph (DAG), and the architecture targets parallel embedded systems composed of multiple processors interconnected by buses and/or switches. This chapter presents new list scheduling heuristics with communication contention. Furthermore, we define new node priorities (top level and bottom level) to sort nodes, and propose an advanced technique named critical child to select a processor to execute a node. Experimental results show that the proposed method is effective to reduce the schedule length, and the runtime performance is greatly improved in the cases of medium and high communication. Since the communication cost is increasing from medium to high in modern applications like digital communication and video compression, the proposed method is well-adapted for scheduling these applications over parallel embedded systems
Extracellular Vesicles Derived from Gram-Negative Bacteria, such as Escherichia coli, Induce Emphysema Mainly via IL-17A-Mediated Neutrophilic Inflammation
Recent evidence indicates that Gram-negative bacteria-derived extracellular vesicles (EVs) in indoor dust can evoke neutrophilic pulmonary inflammation, which is a key pathology of chronic obstructive pulmonary disease (COPD). Escherichia coli is a ubiquitous bacterium present in indoor dust and secretes nanometer-sized vesicles into the extracellular milieu. In the current study, we evaluated the role of E. coli-derived EVs on the development of COPD, such as emphysema. E. coli EVs were prepared by sequential ultrafiltration and ultracentrifugation. COPD phenotypes and immune responses were evaluated in C57BL/6 wild-type (WT), IFN-gamma-deficient, or IL-17A-deficient mice after airway exposure to E. coli EVs. The present study showed that indoor dust from a bed mattress harbors E. coli EVs. Airway exposure to E. coli EVs increased the production of proinflammatory cytokines, such as TNF-alpha and IL-6. In addition, the repeated inhalation of E. coli EVs for 4 wk induced neutrophilic inflammation and emphysema, which are associated with enhanced elastase activity. Emphysema and elastase activity enhanced by E. coli EVs were reversed by the absence of IFN-gamma or IL-17A genes. In addition, during the early period, lung inflammation is dependent on IL-17A and TNF-alpha, but not on IFN-gamma, and also on TLR4. Moreover, the production of IFN-gamma is eliminated by the absence of IL-17A, whereas IL-17A production is not abolished by IFN-gamma absence. Taken together, the present data suggest that E. coli-derived EVs induce IL-17A-dependent neutrophilic inflammation and thereby emphysema, possibly via upregulation of elastase activity.X111613Ysciescopu
The importance of sonographic landmarks by transcutaneous laryngeal ultrasonography in post-thyroidectomy vocal cord assessment
During examination of the vocal cords (VC) using transcutaneous laryngeal ultrasonography (TLUSG), 3 sonographic landmarks (namely, false VC [FC], true VC [TC], and arytenoids [AR]) are often seen. However, it remains unclear which landmark provides a more reliable assessment and whether seeing more landmarks improves the diagnostic accuracy and reliability.
METHODS:
We evaluated prospectively 245 patients from 2 centers. One assessor from each center performed all TLUSG examinations and their findings were validated by direct laryngoscopy. All 3 sonographic landmarks were routinely visualized whenever possible. The rate of visualization and diagnostic accuracy between the 3 landmarks were compared.
RESULTS:
Eighteen patients suffered postoperative VC palsy (VCP). Both centers had comparable visualization or assessability rate of ≥ 1 sonographic landmark (94.9 and 95.3%; P = 1.000) and 100% sensitivity on postoperative TLUSG. The rates of FC, TC, and AR visualization were 92.7%, 36.7%, and 89.8%, respectively. The sensitivity, specificity, and diagnostic accuracy and the proportion of true positives, false positives, and true negatives between using 1, 2, landmarks and 3 landmarks were comparable (P > .05).
CONCLUSION:
Each sonographic landmark had similar reliability and diagnostic accuracy. Identifying all 3 sonographic landmarks was not mandatory and visualizing normal movement in one of the sonographic landmarks would be sufficient to exclude VCP.
Copyright © 2014 Elsevier Inc. All rights reserved.postprin
Hong Kong domestic health spending: Financial years 1989/90 to 2009/10
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