Fine Structure of Chemically Modified Flax Fibre

The changes in fibre structure caused by the realignment of the microfibrils of fibre and yarn samples treated with swelling agents, such as NaOH, LiOH, ZnCl₂, and butyltrimethyl ammonium hydroxide (BTMAH), both under tension and slack, were studied by light and electron microscopy. The structural effects of treatment of the microfibrils and the ultimate fibres correlated with the measured variations in fibre tenacity and moisture regain. The results of differential thermogravimetric analysis suggested that structural realignment of the cellulosic crystals had taken place during the treatments.     

Vinyl ketostearates. Preparation,properties, infrared spectra,and analysis of 4- and 12-ketostearates

Summary Vinyl 12-ketostearate and vinyl 4-ketostearate were prepared by vinylating 12-ketostearic and 4-ketostearic acids, respectively, with vinyl acetate in the presence of a mercuric sulfate catalyst. The crude vinyl esters were purified by extracting the free fatty acids with dilute potassium carbonate, removing the mercury by distillation, and crystallizing successively from acetone and pertroleum ether. Infrared analyses revealed that lactonization occurred with the 4-ketostearic acid during the hydrogenation of the oiticica oil and during the vinylation of the keto acid. Two γ-lactones were produced. The γ-lactone of 4-hydroxy-2-octadecenoic acid was isolated in relatively pure form, and evidence was obtained for the concurrent formation of the less stable γ-lactone of 4-hydroxy-3-octadecenoic acid. The infrared spectra of the methyl keto esters, keto acids, vinyl keto esters, and the γ-lactone of 4-hydroxy-2-octadecenoic acid were determined in carbon tetrachloride solutions. It was found that the characteristic absorbances for the lactone-carbonyl, ester-carbonyl, ketonecarbonyl, and the vinyl group at about 5.6, 5.7, 5.8, and 6.1 microns, respectively, obey the Lambert-Beer law over a wide range of concentrations. Presented at the 33rd fall meeting, American Oil Chemists’ Society, Los Angeles, Calif., September 28–30, 1959. One of the laboratories of the Southern Utilization Research and Development Division, Agricultural Research Service, U. S. Department of Agriculture.     

Individual Differences in the Pattern of Habituation at 5 and 10 Months of Age.

Individual differences in pattern of habituation in fixation time and cardiac change to visual and auditory stimuli are described. Nearly half of the longitudinal sample at 5 months and almost 90% at 10 months did not display a monotonically decreasing habituation pattern over trials, a result that challenges the use of simple indices of response decline as measures of rate of information processing. A positive response to a novel stimulus at 5 and 10 months was observed only if an obvious peak response followed by a decline occurred during familiarization and (for 5-month-old subjects only) if the peak/decline occurred shortly before the introduction of the novel stimulus. Relative to 5 months, habituation patterns at 10 months were flatter and more irregular, and individual differences did not revolve around a few prototypical patterns. No evidence was observed for individual stability in type of habituation pattern across modality within an age or within modality across age, nor were there many correlates between pattern and demographic characteristics of the subjects. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

MIKROPLIS: a hypertext system for design

MIKROPLIS is hypertext software for handling textual information representing designers' reasoning. It is based on PHI (procedurally hierarchy of issues), a refinement of the IBIS (issue-based information system) design method. This article explains the history of hypertext, the PHI variant of IBIS and the MIKROPLIS system itself.     

Aircrew dosimetry using the Predictive Code for Aircrew Radiation Exposure (PCAIRE)

During 2003, a portable instrument suite was used to conduct cosmic radiation measurements on 49 jet-altitude flights, which brings the total number of in-flight measurements by this research group to over 160 flights since 1999. From previous measurements, correlations have been developed to allow for the interpolation of the dose-equivalent rate for any global position, altitude and date. The result was a Predictive Code for Aircrew Radiation Exposure (PCAIRE), which has since been improved. This version of the PCAIRE has been validated against the integral route dose measurements made at commercial aircraft altitudes during the 49 flights. On most flights, the code gave predictions that agreed to the measured data (within +/- 25%), providing confidence in the use of PCAIRE to predict aircrew exposure to galactic cosmic radiation. An empirical correlation, based on ground-level neutron monitoring data, has also been developed for the estimation of aircrew exposure from solar energetic particle (SEP) events. This model has been used to determine the significance of SEP exposure on a theoretical jet altitude flight during GLE 42.     

Lingual action in normal sequential swallowing

Current knowledge about the flexibility in lingual motor control and performance during swallowing is incomplete. The present study aimed at gaining a better understanding of the tongue's motor flexibility and at identifying variable versus invariant lingual motor program parameters in light of changing swallowing task demands (discrete vs. sequential). Specifically, the timing and patterns of tongue-palate contact and the associated changes in tongue shape and action were examined in 5 normal adults using simultaneous electropalatography and ultrasound. Tasks for discrete swallowing included 5 and 30 cc of water; tasks for sequential swallowing involved drinking 200 cc of water at normal and fast rates. Results showed little variation in propulsive contact pattern as a function of task or subject. However, the tongue demonstrated shorter movement duration and overlapping gestures during sequential swallowing. Thus, continuous drinking was performed without changes in motor strategies per se but with changes in the timing coordination of the "drink" and "swallow" action sequences. These findings support the theory that the deglutitive lingual motor program has both invariant and variant parameters, and that movement pattern and action sequence reflect fixed elements within the structure of the motor program, but movement timing can be modified according to the demands of the task at hand.     

Upper critical and irreversibility fields in selectively doped YBa2Cu3O7

The electrical resistivity of (Y_1–xPr_x)Ba₂Cu₃O_7–gd and YBa₂(Cu_1–xZn_x)₃O_7– thin films and (Y_1–x. Tb_x)Ba₂Cu₃O_7– thin films and single crystals has been measured as a function of 0xx_crit, 2KT300K and OTH20T. The samples were oriented withc-axis parallel to applied fields. Upper critical field H_c2 and irreversibility field H_irr values have been determined from these measurements. Increased Tb doping appears to shift H_irr to higher temperatures. This coupled with observed twin peaks in magnetization measurements reflects an enhancement of flux pinning. Unlike Tb which does not appear to alterT _c , Pr and Zn doping of this system tends to depress bothT _c and the slope of the mean field normal phase-mixed phase boundary line (dH _c2/dT).     

Decadal changes in the benthic invertebrate community in western Lake Erie between 1981 and 2004

Faunal surveys of western Lake Erie showed a dramatic change in the species composition and abundance of the invertebrate mud-bottom community. Abundances of formerly dominant ostracods, tubificid and naidid oligochaetes, and chironomids declined 85%, 87%, 80%, and 72%, respectively, between 1982 and 2003. The majority of the declines occurred between 1982 and 1993, when dreissenid abundances were increasing rapidly. Hexagenia nymphs became important members of the infaunal community after 1993. Faunal declines were uncorrelated to weather-related variables. The frequency and magnitude of thermal stratification with accompanying hypoxic conditions during the study period remained within the normal range of variation observed in western Lake Erie. Significant wind events and storm driven seiches that might cause benthos mortality were not correlated with the decadal patterns of faunal decline. Nor were the faunal declines associated with the historical decrease in organic loading, because most of the decrease occurred prior to the study period. Nearly all abundant species declined significantly between 1982 and 1993, but deposit-feeding fauna, eutrophic indicator species, small organisms, and nearshore mud-bottom stations adjacent to dreissenid mussel habitat were most severely affected. These patterns suggest that a systemic change in the trophic structure of western Lake Erie occurred, due mostly to the invasion of dreissenid mussels nearshore and an accompanying diversion of organic matter away from deeper offshore muds. Trophic group amensalism may operate differently in marine and freshwater habitats, although dreissenids may exert ecosystem effects in the Great Lakes similar to oysters in Chesapeake Bay.     

A simple method for collecting infective larvae of Litomosoides carinii

A disabling decrease in range of motion may be a sequelae of ankle trauma. This complication can result from secondary degenerative joint disease, osteochondrial fractures with loose bodies, or posttraumatic adhesive capsulitis. The latter entity is well recognized as a complication of shoulder injuries but is rarely described in other joints. Since adhesive capsulitis produces no specific plain film findings, the confirmation of this diagnosis depends on the usage of a contrast study. It is only recently that ankle arthrography has been utilized to differentiate between the various causes of a painful posttraumatic ankle. Once a diagnosis is established by arthrography, therapeutic efforts can be directed toward relieving the specific abnormality. Three cases of "frozen" ankles are presented. Two were the result of intracapsular fractures, while the third had previously sustained a severe injury of the soft tissue. The arthrographic findings included a decrease in the joint capacity, obliteration of the normal anterior and posterior recesses, and extravasation of contrast material along the needle track.