Studies of human diploid fibroblast growth. I. Responses of normal and hypopituitary cells to fibroblast growth factor, insulin, and serum

We have assayed the growth stimulating activity of bovine insulin, fibroblast growth factor (FGF), and fetal bovine serum (FBS) in diploid human fibroblasts from normal and idiopathic hypopituitary donors. All three factors stimulated DNA synthesis in cells arrested by serum starvation. FGF was active at concentrations as low as 5 ng/ml with maximum effect at 100 ng/ml. FGF stimualted DNA synthesis at lower concentrations than did insulin and also produced a greater maximum response. Only serum was capable of supporting cell division and growth, but FGF accellerated this growth rate when it was added to serum-containing medium. Hydrocortisone, actinomycin D, and cycloheximide inhibit FGF stimulation. There was no significant difference between fibroblasts from normal and hypopituitary donors.     

In vitro bioactivity of titanium-doped bioglass

Previous studies have suggested that incorporating relatively small quantities of titanium dioxide into bioactive glasses may result in an increase in bioactivity and hydroxyapatite formation. The present work therefore investigated the in vitro bioactivity of a titanium doped bioglass and compared the results with 45S5 bioglass. Apatite formation was evaluated for bioglass and Ti-bioglass in the presence and absence of foetal calf serum. Scanning electron microscopy (SEM) images were used to evaluate the surface development and energy dispersive X-ray measurements provided information on the elemental ratios. X-ray diffraction spectra confirmed the presence of apatite formation. Cell viability was assessed for bone marrow stromal cells under direct and indirect contact conditions and cell adhesion was assessed using SEM.     

The published DNA sequence of human cytomegalovirus strain AD169 lacks 929 base pairs affecting genes UL42 and UL43

Compared with the published DNA sequence (M. S. Chee, et al. Curr. Top. Microbiol. Immunol. 154:125-170, 1990), most isolates of human cytomegalovirus strain AD169 contain an additional 929 bp after nucleotide 54612. This results in a changed reading frame for the 5'-terminal 50 codons of gene UL42 and expansion of gene UL43 (a US22 family member) from 187 (3'-truncated) to 423 (full-length) codons. The UL42 and UL43 gene products are nonessential for growth in culture.     

Laser-based ultrasonics on Gr/epoxy composite

Critical issues are examined in the application of laser generation and detection of ultrasound to the inspection of large area air-frame composites. Among these issues are surface roughness, signal-to-noise ratio, insensitivity to the path length between the part and detector, and wide band vs. narrow-band generation. Demonstrated is the feasibility of transmission C-scans of 150 ply Gr/epoxy panels containing simulated delaminations. Waveforms having a signal-to-noise ratio of greater than 40 dB in 15-mm thick Gr/epoxy were obtained with generating laser powers well below the ablation limit for the graphite epoxy. Detection was shot-noise limited with a detector noise figure of about 5–10 dB.     

Determination of residual stresses in thin sheet titanium aluminide composites

Residual stresses in Ti₃Al/SiC composites have been measured using two methods. The compressive residual stresses in the fibers were inferred from measurements of the change in their length when the matrix was entirely removed by etching. The stresses were found to vary substantially from fiber to fiber. The longitudinal and transverse stresses in the matrix were measured by X-ray diffraction. Repeated measurements were made as the outer layer of alloy was removed by electropolishing as far as the first row of fibers. In one composite of lower fiber volume fraction, the matrix stresses were thus found to be approximately uniform throughout the specimen. In a higher volume fraction material, on the other hand, the matrix stresses increased significantly with depth from the outer surface: the longitudinal matrix stresses among the fibers were found to be about 60 pct larger than they were on the specimen surface. The implications of these measurements for processing and reliability of thin sheet titanium aluminide composites are discussed.     

Hand motion prediction for distributed virtual environments

We use our hands to manipulate objects in our daily life. The hand is capable of accomplishing diverse tasks such as pointing, gripping, twisting and tearing. However, there is not much work that considers using the hand as input in distributed virtual environments (DVEs), in particular over the Internet. The main reasons are that the Internet suffers from high network latency, which affects interaction, and the hand has many degrees of freedom, which adds additional challenges to synchronizing the collaboration. In this paper, we propose a prediction method specifically designed for human hand motion to address the network latency problem in DVEs. Through a thorough analysis of finger motion, we have identified various finger motion constraints and we propose a constraint-based motion prediction method for hand motion. To reduce the average prediction error under high network latency, e.g., over the Internet, we further propose a revised dead reckoning scheme here. Our performance results show that the proposed prediction method produces a lower prediction error than some popular methods while the revised dead reckoning scheme produces a lower average prediction error than the traditional dead reckoning scheme, in particular at high network latency.