Current Views Concerning the Liquid State

Investigation of ether in the region of the critical point by the x-ray diffraction methods leads to a new conception of the liquid state. A review is made of authoritative views on the subject and these views discussed in the light of new evidence obtained by x-ray methods. It appears that existing definitions of the liquid state are not adequate and should be supplanted by ones more in conformity with the facts

The Dependence of Cybotactic Groups on Specific Volume

Additional x-ray diffraction data have been taken on ethyl ether in the region of the critical point. (Spangler, Abstract 24, Phys. Rev. 42, p 907, 1932) Series of diffraction curves at pressures of 39.2, 44.1, 49, and 55 kg/cm with temperatures ranging up to 235°C show, as in previous work, that the cybotactic groupings depend more on specific volume than on temperature. At each of the above pressures, the indications of groups disappear at about the critical specific volume regardless of the higher temperatures at higher pressures. The ionization currents were measured with a direct deflection amplifier employing an FP-54 tube instead of the customary electrometer. With this arrangement data could be taken much more rapidly and the fidelity of the results is, in the limit of observation, the same

Results of tests OA26 and IA16 in the NASA/ARC 3.5-foot hypersonic wind tunnel on an 0.015-scale model (36-OTS) of the space shuttle configuration 140A/B to obtain pressures for venting analysis

Tests were conducted, from November 15 to December 4, 1973, to obtain surface pressure data on an 0.015-scale replica of the Space Shuttle Vehicle 4. Data were obtained at Mach numbers of 5.3, 7.4, and 10.3, to support the venting analysis for both launch and entry conditions. These tests were the final tests in a series covering a Mach number range from 0.6 to 10.3. The model was instrumented with pressure orifices in the vicinity of the cargo bay door hinge and parting lines, and on the side of the fuselage at the crew compartment, and below the orbital maneuvering system pods at the aft compartment. The model was tested at angles of attack and sideslip consistent with expected divergencies from the nominal trajectory

Four Stokes parameter radio frequency polarimetry of a flare from AD Leonis

Observations of the four Stokes parameters of a 430 MHz flare from the UV Ceti-type star AD Leonis are presented. The maximum amplitude of the event was 0.52 flux units and the durations at one-half and one-tenth maximum were 12 and 40 seconds, respectively. The degree of circular polarization at maximum intensity was approximately 56 percent and was later observed to be as high as 92 percent. Linear polarization was also observed at a level of about 21 percent at flare maximum which allowed an upper limit of 440 radians - sq m to be placed on the rotation measure

Fruit Pest Events and Phenological Development According to Accumulated Heat Units

Mammals are "warm-blooded" and develop at a constant rate regardless of the environmental temperature, because they are able to maintain an internal temperature that allows their biochemical reactions to progress normally. Insects, which are "exothermic" (the same temperature as their environment; there is no such thing as "cold-blooded"), do not generate body heat, and are therefore limited in their development to periods of favorable external temperature. Below a certain temperature, which varies among species, the insect's biochemical reactions cannot proceed, and development stops. This temperature is known as the insect's developmental threshold ordevelopmental base. By charting the ambient temperature, it is possible to keep track of insect development, which is directly proportional to the amount of time accumulated above the developmental threshold (up to some maximum not often reached during the season). We arbitrarily divide this time into heat units, or degree-days (DD)

Computer Simulation of Cytoskeleton-Induced Blebbing in Lipid Membranes

Blebs are balloon-shaped membrane protrusions that form during many physiological processes. Using computer simulation of a particle-based model for self-assembled lipid bilayers coupled to an elastic meshwork, we investigated the phase behavior and kinetics of blebbing. We found that blebs form for large values of the ratio between the areas of the bilayer and the cytoskeleton. We also found that blebbing can be induced when the cytoskeleton is subject to a localized ablation or a uniform compression. The results obtained are qualitatively in agreement with the experimental evidence and the model opens up the possibility to study the kinetics of bleb formation in detail.Comment: To appear in Physical Review

Emotional and Adrenocortical Responses of Infants to the Strange Situation: The Differential Function of Emotional Expression

The aim of the study was to investigate biobehavioural organisation in infants with different qualities of attachment. Quality of attachment (security and disorganisation), emotional expression, and adrenocortical stress reactivity were investigated in a sample of 106 infants observed during Ainsworth’s Strange Situation at the age of 12 months. In addition, behavioural inhibition was assessed from maternal reports. As expected, securely attached infants did not show an adrenocortical response. Regarding the traditionally defined insecurely attached groups, adrenocortical activation during the strange situation was found for the ambivalent group, but not for the avoidant one. Previous ndings of increased adrenocortical activity in disorganised infants could not be replicated. In line with previous ndings, adrenocortical activation was most prominent in insecure infants with high behavioural inhibition indicating the function of a secure attachment relationship as a social buffer against less adaptive temperamental dispositions. Additional analyses indicated that adrenocortical reactivity and behavioural distress were not based on common activation processes. Biobehavioural associations within the different attachment groups suggest that biobehavioural processes in securely attached infants may be different from those in insecurely attached and disorganised groups. Whereas a coping model may be applied to describe the biobehavioural organisation of secure infants, an arousal model explanation may be more appropriate for the other groups