ALBERT

Description: The ozone profiles obtained from 24 balloon soundings at Uccle (50 deg 48 min N, 4 deg 21 min E) made with electrochemical ozonesondes were used as correlative data for SAGE II ozone profiles retrieved within a distance of at most 600 km from Uccle. The agreement between the two data sets is in general quite good, especially for profiles nearly coincident in time and space, and during periods of little dynamic activity over the area considered. The percent difference between the ozone column density of the mean balloon and SAGE profile is 4.4 percent (-3.3) percent in the altitude region between 10 and 26 km. From a statistical analysis it appears that there is a small but meaningful difference between the mean profiles at the level of the ozone maximum and around the 30-km level. An error analysis of both data sets give similar results, leading to the conclusion that these differences are instrumentally induced. However, differences between the mean profiles in the lower stratosphere are probably real and due to the high ozone variability in time and space in that altitude region.

Description: Walfraven photometry of established and probable members of the Orion OB1 association is presented. Effective temperature, surface gravity, luminosity and mass are derived for all stars, using atmosphere model by Kurucz (1979). Absolute magnitudes are calculated using the Straizys and Kuriliene (1981) tables. Distance moduli and visual extinctions are determined. A comparison of the visual extinctions to IRAS 100 micrometers data shows that the near edge of the Orion A and B clouds lies at a distance of approximately 320 pc, while the far edge is at approximately 500 pc. A method for deriving the ages of the subgroups by comparing theoretical isochrones to the observations in the log g, log T(sub eff) plane is presented. The derived ages suggest, contrary to earlier studies, that subgroup 1b is younger than 1c, which can possibly be explained by past geometries of the system of stars and gas. The initial mass function for Orion OB1 is derived with the aid of the Kolmogorov-Smirnoff test. Through extensive simulations, we show that it is very difficult to derive accurately the Initial Mass Function (IMF) from the available data. To within somewhat weak limits the IMF is found to be of the form xi(log M) = AM(exp -1.7 +/- 0.2) for all subgroups. The energy output of the subgroups in the form of stellar winds and supernovae is calculated and compared to the observed size and expansion velocity of the Orion-Eridanus bubble. It is shown that the energy output of the association can account for the morphology and kinematics of the interstellar medium (ISM).

Description: The effect of microgravity on the recruitment patterns of the soleus, gastrocnemius, and tibialis-anterior muscles was investigated by comparing electromyograms (EMGs) of these muscles of Rhesus monkeys implanted with EMG electrodes, taken before and after a 14-day flight on board Cosmos 2044. It was found that the EMG amplitude values in the soleus muscle decreased after the spaceflight but returned to normal values over the 2-wk recovery period. The medial amplitudes of gastrocnemius and tibialis anterior were not changed by flight. Joint probability density distributions displayed changes after flight in both the soleus and gastrocnemius muscles, but not in tibialis anterior.

Description: The neural circuitry of the lumbar spinal cord can generate alternating extension and flexion of the hindlimbs. The hindlimbs of adult cats with complete transection of the spinal cord at a low thoracic level (T12-T13) can perform full weight-supporting locomotion on a treadmill belt moving at a range of speeds. Some limitations in the locomotor capacity can be associated with a deficit in the recruitment level of the fast extensors during the stance phase and the flexors during the swing phase of a step cycle. The level of locomotor performance, however, can be enhanced by daily training on a treadmill while emphasizing full weight-support stepping and by providing appropriately timed sensory stimulation, loading, and/or pharmacologic stimulation of the hindlimb neuromuscular apparatus. Furthermore, there appears to be an interactive effect of these interventions. For example, the maximum treadmill speed that a spinal adult cat can attain and maintain is significantly improved with daily full weight-supporting treadmill training, but progressive recruitment of fast extensors becomes apparent only when the hindlimbs are loaded by gently pulling down on the tail during the stepping. Stimulation of the sural nerve at the initiation of the flexion phase of the step cycle can likewise markedly improve the locomotor capability. Administration of clonidine, in particular in combination with an elevated load, resulted in the most distinct and consistent alternating bursts of electromyographic activity during spinal stepping. These data indicate that the spinal cord has the ability to execute alternating activation of the extensor and flexor musculature of the hindlimbs (stepping) and that this ability can be improved by several interventions such as training, sensory stimulation, and use of some pharmacologic agents. Thus, it appears that the spinal cord, without supraspinal input, is highly plastic and has the potential to "learn," that is, to acquire and improve its ability to execute full weight-supporting locomotion on a treadmill belt.

Description: S3 Data Acquisition and Control System, (S3DACS) monitors, controls, and records information acquired during tests and presents it in various formats for easy access by large number of users. Results automatically stored. Data used in computations, and selectively presented in tabular, graphical, or electronic form. Reports show current or historical events. Network software written in FoxPro/LAN 1.02 and 80386 Assembler.

Description: Homogeneous Walraven (VBLUW) photometry is presented for 5260 stars in the regions of five nearby southern OB associations: Scorpio Centaurus (Sco OB2), Orion OB1, Canis Major OB1, Monoceros OB1, and Scutum OB2. Derived V and (B - V) in the Johnson system are included.

Description: Report describes experimental and theoretical study of effect of thermal convection on shape of interface between solid and liquid succinonitrile, clear commercially available plastic, in Bridgman (directional-solidification) apparatus in vertical and horizontal orientations.