A note on nonperiodic undamped oscillations,with special reference to brain waves

Nonperiodical sustained fluctuations of electrical potential are characteristic of the rhythms of cortical electric activities. A nonperiodical negatively or positively damped oscillation would be a general solution of any first order linear system of differential equations. Attention is called to a somewhat specialized type of a system of ordinary linear differential equations, which are used by Vito Volterra (Leçons Sur la Théorie Mathématique de la Lutte Pour la Vie, Paris, Gauthier-Villars, 1931) in his theory of interdevouring species. This system of linear equations leads to nonperiodicalundamped oscillations and admits several plausible interpretations in terms of possible biophysical reactions in the brain. A number of new problems is posed and discussed by this study.     

A note on the use of cross-linked starch in microbiology with special reference to detecting amylase production

Anilogel-E, a cross-linked starch, can be used with distinct advantages where native starch or soluble starch are conventionally used, e.g. in scoring for amylolytic organisms, as an ingredient of fermentation media, and in enhancing protoplast regeneration. It is particularly useful for the direct visualization of amylase producing micro-organisms on solid media, making prior replication of colonies unnecessary.     

A note on the use of cross-linked starch in microbiology with special reference to detecting amylase production

Anilogel-E, a cross-linked starch, can be used with distinct advantages where native starch or soluble starch are conventionally used, e.g. in scoring for amylolytic organisms, as an ingredient of fermentation media, and in enhancing protoplast regeneration. It is particularly useful for the direct visualization of amylase producing micro-organisms on solid media, making prior replication of colonies unnecessary.     

Beak marks on butterfly wings with special reference to Japanese black swallowtail

Birds are believed to be one of the principal predators of butterflies. The beak marks (BMs) left on the butterfly wings are useful indices of bird predation. We performed 84 collections in grasslands and woodlands during 2002–2006 in Ito, Shizuoka prefecture, and collected 893 specimens belonging to 48 species. In general, the larger was the body size the higher was the BM rate. There were two peaks in the BM rate and the peaks were higher by 13–14 % in autumn than in spring in both grasslands and woodlands. During 2007 and 2008, capture-mark-recapture surveys were conducted 82 times in a flight path of black swallowtail butterflies (BSBs). A total of 443 BSB were individually marked and released at a site 400 m away from the flight path after examining for BM, degree of wing damage, body size, sex and species. The BM% of BSB ranged from 40 to 46 %, which was the highest among the observed butterflies. The recapture rate was negatively correlated with the BM rate suggesting that the avian predation was strong enough to affect the survival rate of BSB adults. In addition, the BM rate showed a delayed positive response to BSB density in the previous month. Variation in the BM rate was analyzed with a multivariate model; it indicated that month and wing length were significant explanatory variables. In addition, the highest BM rate was observed at an intermediate wing size. These results strongly suggested that variation in the BM rate was caused by variation in avian life history and predator size. All the evidence suggested that an appreciable predation pressure by birds operated on BSB adult populations.     

Superovulation in nonseasonal Japanese native goats, with special reference to the developmental progression of embryos

Treatment for superovulation with pregnant mare serum gonadotropin (PMSG) and follicle stimulating hormone (FSH) was carried out in nonseasonal breeder Japanese goats which are widely used as a substitute model for cattle in various studies in Japan. The proportion of females that came into estrus (93 and 99%) and the interval between PGF(2) administration and estrus (1.5 to 2.0 days) did not differ between females treated with PMSG and those treated with FSH. The number of normal embryos recovered was significantly higher (P<0.01) in FSH-treated (9.4 +/- 5.6) femals than in PMSG-treated females (5.7 +/- 4.4). The developmental stage of embryos recovered from 1.0 to 8.5 at 0.5-d intervals after mating is also described. The development to the two-cell, four-cell, eight-cell, morula, blastocyst and zona-free blastocyst stage was first observed 1.5, 2.5, 5.0 to 5.5, 6.0 and 6.5 d, respectively, after human chorionic gonadotropin (hCG) injection.     

A note on the karyotypes and chromosome associations of the Hylobatidae, with special reference to Hylobates (Nomascus) concolor

The somatic chromosomes, obtained from short term leukocyte cultures, were studied of four species of the Hylobatidae: Hylobates lar, H. agilis, H. (Nomascus) concolor and Symphalangus syndactylus. In accordance with earlier observations by others, the diploid chromosome numbers were found to be 44 in both Hylobates lar and H. agilis, 52 in H. concolor and 50 in Symphalangus syndactylus. The chromosome associations observed in metaphase spreads are clearly different in the three types of chromosome complements. In Hylobates lar and H. agilis associations are found between both members of the marked chromosome pair. In Symphalangus syndactylus the only two acrocentric elements of the karyo-type, which are of medium size, associate frequently. In H. concolor finally, the members of three pairs of small acrocentrics are involved in chromosome associations. G-banding patterns (obtained by trypsin treatment) showed that in a male individual of this species also the small acrocentric Y chromosome sometimes participates in these associations. The evolutionary aspects of these observations are briefly discussed.     

Nutritional aspects of anastomotic operations with special reference to the sprue syndrome

Necessary but radical operation which results in short-circuits between various levels of the digestive tract, with or without resections of portions of the esophagus, stomach or intestine, frequently cures the condition for which the operation was done, but leaves the patient with difficult nutritional problems. These nutritional disturbances are usually associated with inability to maintain or gain weight as a result of badly regulated movement of food material through the altered digestive tract, and by the removal or diversion of important digestive secretions, such as those elaborated by the stomach, pancreas, duodenum and small bowel. Increased intestinal rate and diminished specific gastrointestinal secretions reduce the ability of the small bowel to properly absorb food, with resulting malnutrition, deficiency disease, and at times specific avitaminosis. Inability to absorb fat and fat-soluble substances is a constant feature of these conditions. Successful treatment of the nutritional problems involves constant, prolonged overfeeding of nonbulky foods, usually given in regular, frequently administered meals of small volume. Vitamin concentrates may occasionally be of some temporary assistance but are not needed if a balanced diet is given and may cause undesirable and sometimes dangerous symptoms. The use of supplemental substances, such as liver extract and a wetting agent, such as "Tween 80," to improve fat absorption have been demonstrated to be of value.The postoperative conditions described are fairly similar to the condition known as sprue, and it is possible that the general principles underlying the treatment of this disease apply to the entire group of post-operative nutritional disturbances alluded to.     

A cytogenetic study of a population of retarded females with special reference to the fragile(X) syndrome

Summary A cytogenetic survey of a population of 278 mentally retarded females on community placement is described. Thirty-five females had an aneuploid chromosome constitution and a single female was found to have the fra(X) syndrome. The frequency of the fra(X) syndrome among female retardates is discussed together with the apparent absence of de novo mutants among this class of fra(X) probands.