Ceramic microstructure detected by NMR relaxation and imaging of fluids in the pores

NMR Relaxation and Imaging have been applied to study preparation processes of ceramic porous samples. Relaxation analysis gives a clear characterization of the materials, with high sensitivity. Differences in the method of preparation and steps as low as 25 degrees C in the firing temperatures are well detectable. Furthermore, the images permit distinguishing the different samples. The effects of the contrast in relaxation times dominate those due to the different porosities of the samples. Scanning Electron Microscopy confirms the interpretation that the changes in relaxation times are due to different pore space structures associated with the different firing temperatures. The higher the firing temperature, the larger are the pores and the higher is the amount of compact, sintered matrix, leading to higher relaxation times.     

Structure-activity of type I interferons

Type I IFNs constitute a family of proteins exhibiting high homology in primary, secondary, and tertiary structures. They interact with the same receptor and transmit signals to cellular nucleus through a similar mechanism, eliciting roughly homogeneous biological activity. Nevertheless, the members of that family, IFN alpha species, IFN beta and IFN omega, due to local differences in the structure sometime show distinct properties. From the reported data it results that even minute changes or differences in the primary sequences could be responsible for a significant variety of biological actions, thus inducing to the hypothesis that Type I IFNs, rather than to be the result of a redundant replication during the evolution play definite roles in the defense of living organisms to foreign agents.     

DNA synthesis of human, mouse, and rat mammary carcinomas in vitro: influence of insulin and prolactin

Carcinomatous mammary tissues, derived from six spontaneously arising mouse mammary tumors, six DMBA-induced rat mammary tumors, and 26 biopsy specimens of human breast tumors, were processed into slices and each tumor was inidvidually cultured for two days in Medium 199. The influence of bovine insulin (5.0 mug/ml) and ovine prolactin (10.0 mug/ml) on H3-thymidine incorporation into DNA was determined on the cultured tumor slices. Insulin consistenly (p less than 0.05-0.01) increased the incorporation of H3-thymidine into DNA of the organ cultures of mouse, rat, and human mammary carcinoma slices. The stimulatory effect of insulin was quantitatively more prominent in the mouse tumor slices than in the rat or human slices. The addition of prolaction to the insulin-containing culture medium further increased significantly (p less than 0.001) the incorporation of H3-thymidine into DNA of rat mammary carcinoma slices but had no significant effect on cultures of either mouse or human mammary carcinomas. The addition of prolactin to insulin and hydrocortisone-enriched medium containing slices of 20 individually cultured human breast carcinomas did not significantly influence the mean incorporation of H3-thymidine into DNA. However, a very small fraction (approximately equal to 15%) of these human breast carcinomas responded to prolactin by increasing the incorporation of H3-thymidine into DNA to a degree quantitatively comparable to the prolactin-sensitive, DMBA-induced rat mammary carcinoma. These results suggest that a very small fraction of human breast malignancies may respond to the growth-stimulatory effects of prolactin, but that the vast majority mimic more closely the prolactin-independent mouse mammary carcinoma.     

Partial replacement of chicken semen by turkey semen in artificial insemination of chickens

Chicken semen undiluted, diluted with a diluent containing fructose and/or mixed with turkey semen was used to inseminate Leghorn hens. In two of three experiments there was an improvement in fertility from insemination by mixed semen as compared to semen diluted to the same extent with the diluent.     

Measurement of thrombus formation on intravascular catheters

War is a complex social situation due to the interplay of multiple factors. Economical and political ones are of utmost importance, but human attitudes and motivations must be also taken into account. Being desirable to modify human transactions in such a way that they do not interfere with the basic right of everyone to a condition of physical and mental well-being, war must be abolished. The author contends that an understanding of behaviour through Psychology can be helpful in that aim. Aggression is considered the principal psychological cause of war. It is worth while to differentiate between aggression as an instrument for attaining a special end, and as pure hostility. Only in the first form, it is held here, does it play an important role in war. Psychogists must deal also with a wide range of states of mind that can be "served" by aggression: feelings of inferiority or insecurity, fear, greed, projections, compensations, rationalizations, etc. Scientific approach is not the only one Physiology brings to war prevention. It is equally important the wide dissemination of its conclusions among the general public. Information on the dynamics that prompt people to decide war would make it easier to control. This applies not only to political or military leaders, but also to civil populations. Concerning those two possible contributions of psychologists, scientific and educative, it is suggested the extensive use of psychodramatic techniques. Their richness lie in the lifelike experiences they convey to the participants, and particular aptitude to promote changes of attitudes. Investigation and information on the psychological processes related to war should be undertaken by international organizations of social scientists, acting simultaneously in several countries. Some of the initial steps they could further: 1) that prevention of war be a current subject matter in psychological courses; 2) that the World Health Organization take interest in this subject; 3) that psychologists participate in international political and economical bodies in order to clarify the psychological factors leading to war.     

Fatty Acids Released from Milk Fat by Lipoprotein Lipase and Lipolytic Psychrotrophs

ABSTRACT: The ability of 13 different strains of psychrotrophs to release free fatty acids in milk was evaluated by using GC analysis. The 13 strains could be categorized into 3 groups: Group 1 consisted of bacteria that grew well and released large quantities of free fatty acids, group 2 consisted of bacteria that grew well but released low amounts of free fatty acids, and group 3 consisted of bacteria that did not grow well nor released large quantities of fatty acids. In group 1, 3 strains were determined to be highly lipolytic, releasing short‐chain fatty acids in amounts greater than reported threshold values. Group 3 consisted of 2 strains, which did not grow well in heat‐treated milk, and the subsequent release of free fatty acids was minor during the 10‐d monitoring time. The other 8 strains tested showed no specific pattern of fatty acid release and quantities of short‐chain fatty acids were not large, despite the ability to grow to high numbers in the treated milk. This work indicates that the lipolytic activity of psychrotrophs common in raw milk is specific to the species and a general prediction of free fatty acid release may not be possible.