Analysis of changes in relative elemental growth rate patterns in the elongation zone of Arabidopsis roots upon gravistimulation

Although Arabidopsis is an important system for studying root physiology, the localized growth patterns of its roots have not been well defined, particularly during tropic responses. In order to characterize growth rate profiles along the apex of primary roots of Arabidopsis thaliana (L.) Heynh (ecotype Columbia) we applied small charcoal particles to the root surface and analyzed their displacement during growth using an automated video digitizer system with custom software for tracking the markers. When growing vertically, the maximum elongation rate occurred 481 +/- 50 microns back from the extreme tip of the root (tip of root cap), and the elongation zone extended back to 912 +/- 137 microns. The distal elongation zone (DEZ) has previously been described as the apical region of the elongation zone in which the relative elemental growth rate (REGR) is < or = 30% of the peak rate in the central elongation zone. By this definition, our data indicate that the basal limit of the DEZ was located 248 +/- 30 microns from the root tip. However, after gravistimulation, the growth patterns of the root changed. Within the first hour of graviresponse, the basal limit of the DEZ and the position of peak REGR shifted apically on the upper flank of the root. This was due to a combination of increased growth in the DEZ and growth inhibition in the central elongation zone. On the lower flank, the basal limit of the DEZ shifted basipetally as the REGR decreased. These factors set up the gradient of growth rate across the root, which drives curvature.     

Experiment and numerical simulation of double-layered RC plates under impact loadings

This paper is to investigate and to propose a method to improve the impact resistance of reinforced concrete (RC) plates against projectile impact, and the damage of double-layered RC plates is examined experimentally and simulated analytically. In tests, a projectile launching apparatus, which is a 40 mm smooth-bore airgun, was used. Based on experimental results, numerical simulations with the DYNA-3D code, which takes account of the dynamic constitutive law of concrete, were done to find the applicability of the present computer code to the analysis of double-layered RC plates under high-speed impact loadings. In this study, the impact resistance of concrete plate is defined as the degree of local damage. In both experiments and numerical simulations, the effect of double-layering on the impact resistance is discussed.     

Usefulness of simple endoscopic aspiration cytology of pancreatic juice for diagnosis of early pancreatic neoplasm. A prospective study

For detection of early cancer of the pancreas, endoscopic aspiration cytology of pancreatic juice without endoscopic retrograde pancreatography was performed in 64 consecutive outpatients who had symptoms or findings that suggested pancreatic disease. Patients with positive or suspicious cytologic results or abnormal US findings were admitted and underwent detailed examinations. Positive and suspicious cytologic results were obtained in 2 and 10 patients, respectively. Of those with positive and suspicious cytologic results, two, and one patient, respectively, were ultimately found to have pancreatic neoplasms. Of these three resected specimens, one was in situ carcinoma and two presented marked atypia. All patients were alive with no evidence of recurrence. No further cases of pancreatic neoplasm were found. Complications from the procedure did not develop in any patient. This technique is useful in the diagnosis of early neoplasms of the pancreas, because it is simple and safe to perform for outpatients.     

Photorealistic image synthesis for outdoor scenery under various atmospheric conditions

We propose a method for displaying photorealistic images of outdoor scenes suitable for displaying simulation results, such as the appearance of a building under various weather conditions. This method portrays the changes in perceived color of buildings under various atmospheric conditions by taking into account the spectral distribution of both direct sunlight and sky light. Such views of buildings (including the effects of atmospheric particles like clouds, fog, and light beams) are useful for the design not only of buildings, but also of whole city areas.     

Serial MRI findings of benign poliomyelitis

Clinical and electrodiagnostic evaluations were performed in 25 patients with electric burns who were injured 2 to 13 years before the study. Abnormal motor nerve conduct findings were detected in 12 of the patients. In nine patients, abnormalities were observed in more than one nerve. There was a positive relation noted between age and nerve lesions. Weakness was the most prominent clinical finding.     

Suppressive effects of the endothelin receptor (ETA) antagonist BQ-123 on ET-1-induced reduction of lipoprotein lipase activity in 3T3-L1 adipocytes

Endothelin (ET)-1 reduced heparin-releasable lipoprotein lipase (LPL) activity in 3T3-L1 adipocytes in a concentration-dependent manner. However, a selective ETB receptor agonist, [Ala1,3,11,15]ET-1, did not act like ET-1. The ET-1-induced decrease in LPL activity was suppressed by a selective ETA receptor antagonist, BQ-123: the concentration-response curve for the ET-1 reduction of LPL activity was shifted to the right in the presence of BQ-123 in a concentration-dependent manner. This antagonistic effect of BQ-123 clarifies that the ETA receptor is responsible for the ET-1-induced reduction of LPL activity in 3T3-L1 adipocytes, which suggests that there is therapeutic potential for ETA antagonists in LPL-related lipoprotein disorders.     

Optic neuritis and vitamin C

We examined the eye-fixation pattern of a patient with severe left unilateral spatial neglect who showed leftward searches of various extent in more than half of line bisection trials. Because of complete left homonymous hemianopia, he perceived only the segment of the line between its right endpoint and the point of the leftmost fixation. In the trials with leftward searches, he frequently placed the subjective midpoint on the right part of the perceived segment. In the trials without leftward searches, he placed it near the left extreme point of the perceived segment. For all these bisections, the subjective midpoint was constantly placed far to the right of the true midpoint of the line irrespective of the length perceived. We consider that in severe left unilateral spatial neglect, rightward attentional bias is the predominant factor that determines where to place the subjective midpoint. Transient attentional shift to the left may produce leftward searches, but it does not induce effective processing of line bisection.     

Effect of branching of polyolefin backbone chain on catalytic gasification reaction

A basic study on the catalytic gasification of polyolefins such as PE and PP, which account for a major part of general waste plastics, was conducted in order to develop a technique for effective recycling of these wastes. In the case of PE, the gasification of PE is considered to consist of the following scheme: polymer → catalytically degraded polymer → catalytically degraded oligomer → liquid component → gas component. The gasification of PE does not occur directly from the polymer chains, but gaseous C₄ substances are selectively found from the liquid components with the highest branching frequency. The overall yield of C₄ components including isobutane was 74.5 and 60.5% molar for PE and PP. These liquid components (gasification precursors) have the branching frequencies. For example, a molecule with M?_w of 400 contains about eight branches for every 30 methylenes. From the catalytic gasification of PE, PP, and PIB, the gas conversion rate is also found to increase with increasing frequency of the backbone branching. It is concluded that the branching frequency is the key factor governing the gas conversion rate of polyolefins.     

Strength of glass with vacuum-deposited metal films: Cr,Al, Au and Ag

Fracture strength of acid-etched glass with vacuum deposited metal films is investigated. The strength of the etched glass having an initial value of 1696±39 MN m⁻² reduces to 265±10 MN m⁻² with 69 nm thick Cr film coating. Al film coating also causes the strength reduction, but the reproducibility of the strength is not found even under strictly controlled evaporation conditions. In ambient air, the strength of Au- and Ag-coated glasses maintains the initial high strength value and slightly increases with film thickness. From strength reduction behaviour of Cr-coated glass and dynamic fatigue characteristics for Ag-coated glass, it is highly probable that rupture of the metal film takes place before fracture of the glass occurs, and the flaw formed in the film propagates under loading into the glass to act as a Griffith crack.