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A laboratory study is described of the effect of ageing on the removal of fatty oils from wool yarn. When newly oiled yarn was scoured in package form, high and unevenly distributed oil residues were obtained, but scouring improved as the oil oxidized on the ageing of the yarn. The effect of ageing was of much less significance when the yarn was scoured in hank or fabric form because satisfactory scouring was obtained when the yarn was new. This improvement in package-scouring is associated with the droplet size of the emulsion formed during scouring. Unoxidized oil produces relatively large droplets, a large proportion of which are retained by the yarn during circulation of the liquor, which results in high and uneven residues. Oxidized oil produces many small droplets that are not retained by the yarn, so that low oil residues are thus obtained. In hank- and fabric-scouring, the liquor is not recirculated and hence the droplet size of the emulsion is of little importance.

(1974). The Effect of Temperature and Regain Changes on the Ageing of Wool Fibres. The Journal of The Textile Institute: Vol. 65, No. 1, pp. 55-57.

In a previous paper it was shown that if a high phosphorus-containing stainless steel is quenched directly from solution treatment temperatures of 1100 and 1300°C to ageing temperatures in the range 400 to 750°C, a complex series of precipitates and quenching defects is formed. The present paper describes a transmission electron microscope study of some of these defects. Specifically, an attempt has been made to characterize their nature and geometry using diffraction contrast analysis.

The development of sharp yield drops in Cu 3 Au on ordering has been discussed in the preceding paper. The examination of possible mechanisms responsible for the discontinuous yielding led to the conclusion that the single dislocation yield model was not responsible for the yielding. Both the model of pinning of superlattice dislocations in the cube plane configuration and the APB pinning model gave reasonably good agreement with experimental results and it was therefore not possible to decide which mechanism was operating. It has now been established that yield drops also develop when ordered-strained material is aged prior to final testing. The single dislocation model would predict no strain-ageing yield drop, since superlattice dislocations would be present as a result of the initial straining. Furthermore, the kinetics obtained for onset of the strain-ageing yield at various temperatures are inconsistent with the cube-plane configuration model. An APB pinning mechanism gives better agreement than either of the other mechanisms. It has also been inferred that the mechanisms responsible for yield drops in ordered material and ordered strain-aged material are identical.

The paper describes changes in the interrenal gland of a laboratory-bred population of Lebistes reticulatus (Peters) throughout life. Changes in the volume of the interrenal tissue, the height of the interrenal cells, and interrenal nuclear volume were measured; and detailed recordings of cytological characteristics were kept. Differences were found between female and male fish. In young female Lebistes the interrenal tissue was disposed in long cords of cuboidal or polygonal cells, with sparse cytoplasmic granulation. With increasing age there was a tendency for the volume of the interrenal gland to increase, whilst there was a steady fall in cell height and also a decline in the volume of the nucleus. There was a marked increase with age in cytoplasmic granulation of the interrenal cells, with nuclear changes apparent in the increased staining reaction and pycnosis of the nuclei. In young male Lebistes the arrangement of the interrenal gland, which occurred more anteriorly than in female fish, was principally in groups of polygonal cells containing pale-staining granules. With advancing age there was a marked increase in the volume of the gland, whilst the volume of the cell nucleus fell. There was no change in interrenal cell height with age, and only a slight increase in cytoplasmic granulation. Interrenal cells with pycnotic nuclei were more numerous in old male fish than in old females. Chromaffin tissue occurred as small groups of pale-staining cells surrounded or bordered by interrenal cells. There was no evidence of any marked change in the amount of chromaffin tissue with age; great individual variations were found throughout life. Chromaffin cells with an unusually large basophilic nucleus were recorded in old fish of both sexes. The general impression was one of decreasing interrenal activity with age; the increased granulation was considered to be associated with degeneration and pycnosis of cells, rather than with increased secretory activity. The appearance of the gland in old age was similar to that found in hypophysectomized fish, and it was suggested that the ageing changes in the interrenal tissue of Lebistes may reflect a gradual decrease in the secretion of adrenocorticotrophic hormone by the ageing pituitary gland.

Reciprocal hybrids of two highly inbred strains of Drosophila melanogaster , Gabarros 4 and Abeele, were cultured, at a preimaginal population density of 30 eggs per standard vial at the temperatures of 16, 19, 22, 25, 28 and 31°C. Afterwards for every preimaginal temperature considered and for the whole life, the daily egg-production of females of known size and duration of development was counted, at 25°C. Life-span was also recorded. The mean total fecundity does not vary in function of the preimaginal temperature, exception made for the extreme 31°C. The mean daily egg-production, the size and the duration of development decrease with the increase in preimaginal temperature. Life-span at 25°C is prolonged when that temperature is decreased; life-span is thus positively correlated with size and duration of development. In a previous experiment, the life-span at 25°C of hybrids cultured at 25°C and at various preimaginal population densities was positively correlated with duration of development and negatively with size. The regressions longevity-duration of development observed in both experiments are of an identical sign; they differ however significantly. It is therefore concluded that longevity is not determined solely by preimaginal duration of development and that more of one developmental factor must be involved. The next paper in the series will compare and discuss the results of both experiments.

That progressive increases in the time required to initiate certain enzyme inductions in rat liver in vivo may be used as a biochemical parameter of ageing was reported previously. The present paper indicates that a second biochemical manifestation of mammalian senescence may be a modification in the regulation of DNA synthesis and cell division in vivo. Administration of isoproterenol to 2-month-old rats initiates a single, tissue-specific burst of DNA synthesis, mitosis and division of certain salivary gland cells. Upon administration of identical body weight dosages of isoproterenol to older rats, it is evident that: 1. the time required to initiate DNA synthesis increases progressively and is directly proportional to the chronological age of rats from 2 to at least 24 months; 2. the delayed onset of DNA synthesis may be accompanied by a decreased magnitude of response; and 3. the ability to stimulate cell division may be abolished. These impairments probably are not attributable to changes in either the transport or pool size of deoxynucleotide precursor or in the immediate binding of isoproterenol. It seems likely, therefore, that age-dependent changes in the metabolism of RNA, protein and/or isoproterenol are responsible.

In the previous two studies it was shown that, beginning with maturation, definite progressive morphologic and physiologic changes took place in the egg, both within and without the body, such as (i) an increase in volume of the egg, (2) a loss of sur rounding jelly layer, (@) a retardation in the rate and change in the manner of forming the fertilization membrane, (@) a retarda tion and inhibition in cleavage. These changes served as measur able and corroborative evidences of the physiologic condition or vitality of the eggs of a female at any time, and served to measure the deterioration or loss of vitality with age. There were other symptoms or evidences of physiologic de terioration, especially in late stages of ageing, or overripening, which will be discussed briefly in this paper. These changes include: (i) Agglutination of eggs, (2) fusion of eggs, (3) abnormal cleavage, (4) separation of blastomeres and (@) cytolysis of the eggs. The same technique, the same nomenclature, the same pre cautions and the same three species of sea urchin were used as in Parts I. and II. For details of these I must refer to these studies.

It is said that the cold-rolled Al-Mg alloy sheets decrease their tensile strength during ageing. In this paper, the result of study on various effects of ageing on Al-2-8%Mg alloy sheets is reported.The decrease of hardness and tensile strength of Al-2-8%Mg alloy sheets was recognized from the preliminary experiment.In order to prevent the decrease of hardness and tensile strength, the authors studied two methods of (1) heat treatment, and (2) addition of the third element.The results obtained were as follows.(1) The annealing of 100°C ×1hr. stabilized tensile strength of these alloy sheets, and reduced the rate of increase of elongation.(2) The addition of 1.0%Cr and 1.0%Mn seemed to repress somewhat the decrease of tensile strength and the increase of elongation.

The experiments in this paper were planned to study the mechanisms of release of ovipositional behaviour in bombyx mori . For this purpose, egg-laying and the spontaneous discharges of motor neurons in G IX were compared between mated and virgin females. The spontaneous discharges of motor neurons in G IX were recorded extracellularly from the nerve bundles of the isolated G IX bathed in a mixture of Ringer's solution and body fluid. The mating stimulated egg-laying so definitively that within 24 hr from the removal of males the mated females laid most of the eggs stored in the genital organs. Ageing of the moth accelerated the egg-laying of the virgins: the number of unfertilized eggs laid by virgins within 2 days from emergence was 10 to 20 per cent of the number of fertilized eggs laid by the mated females within 24 hr, but the number of unfertilized eggs laid within 7 days by the virgins reached 60 to 70 per cent. On the other hand, mating activated the spontaneous discharges of motor neurons in G IX. Moth age had a slight effect on the spontaneous discharges of motor neurons in G IX of the virgins. In recording the spontaneous discharges of motor neurons in G IX, the only changed factor was the body fluid outside the ganglion itself. Therefore, it was postulated that mating changed the humoral condition of the female. This change may stimulate the motor neurons in G IX, and then the egg-laying of mared females may be activated.

The paper studies the influence of ageing on the electroluminescence of ball milled powders of zinc sulphide and it is shown that partial recovery of the electroluminescence (EL) brightness of ball milled samples occurs. The EL brightness of a non-milled sample did not change with ageing. The recovery of EL ball milled samples is explained by the recovery of the EL barriers by diffusion of the copper ions which were dispersed over the crystallites of the EL powders by ball milling.

In order to eliminate maximum in the hardness-time curve of Corson alloy aged at 500°, an attempt is madee so that the matrix of solid solution may be made more viscous by an addition of elements. As the adding elements, Al, Fe, Co and Cr were selected, the amount for Al being 1_??_10% and others for less than 5% each. Although the object can be attained to a certain extent by a mere addition of Al, further improvement was made by additions of Fe and Co besides Al. Cr was not as much effective as was Fe and Co. Those alloys, which do not show the maximum by ageing at 500°, also showed the maximum by ageing at 550°. This phenomenon seems, to play an important role in the age-hardening theory, but it will be related in a later paper and here are given only mechanical properties of Corson alloy and modified Corson alloys by Fe or Co, an example of which is given below:- _??_.

Changes in the giant mitochondria (sarcosomes) in the flight muscles of the ageing housefly Musca domestica L. have been quantitatively determined and the results incorporated in the present paper. Variations in mitochondrial size and number are both sex-related and age-dependent. In the male fly both mean size as well as the total number of mitochondria per fly increase up to the beginning of the second week and then begin to decline by the end of the second week. In the female, the maximum size and number are also reached by the third day and remain unchanged until the end of the third week, at which time both size and number then show a dramatic decline. From observations of specific changes in the populations of differently sized sarcosomes, it is inferred that multiplication, growth, and lysis of mitochondria are continuous processes throughout the life-span of the flies, but that their rates differ with age. In the male fly these changes in size and number of the mitochondria are preceded by the loss of wings and a decline in ATP-ase and in alpha-glycerophosphate dehydrogenase activities, whereas in the female fly such mitochondrial variations occur with the decline in the physical and biochemical functions of flight.

An attempt is made here to explain the observed phenomena in the yielding and ageing of mild steel, described in two previous papers, in the general terms of a grain-boundary theory. On this hypothesis, a satisfactory explanation of the variation of the lower yield point with grain size may be developed. It is shown that strain-ageing must involve two processes: a healing of the grain-boundary films, coupled with a hardening in the grains themselves. A discussion of the possible nature of the grain-boundary film is also undertaken.

The present paper is in two main parts: (1) a general discussion of the population factors which have led to a focusing of attention upon ageing with some reference to recent advances in gerontology and (2) a consideration of the actuarial implications of current gerontological research.

I. Summary The present paper is based on the examination of lower jaws from some 3000 individuals of Hippopotamus amphibius L. which were collected in the course of cropping operations in the Queen Elizabeth Park, Uganda between 1961 and 1966. It extends an earlier study by W. M. Longhurst, who described 20 relative age groups based on tooth replacement and wear. The age groups, slightly modified, are described and illustrated here and should serve as a useful field guide. Mean chronological ages from 0–43 years have been allocated to the groups. Checks which confirm the validity of the ages allotted are presented and discussed. These include correlation with the mandibular age group of six known-age animals; findings on the age-related incidence of rinderpest-neutralising antibodies; the orderly progress of fusion of the mandibular symphysis and rate of loss of the first premolar. Growth layers present in the teeth are discussed. The growth of the eye lens is also described. After an initial phase of rapid growth the lens continues to grow throughout life and follows a rectilinear pattern from an estimated age of eight years onwards. This is expected from the findings of similar studies on other species for which known-age specimens are available. Variability of lens dry weight at age is relatively small and indicates that the estimated ages are reasonably precise. Growth of the mandible is analysed and is not inconsistent with the ages allotted. A marked sex difference in mandible weight at age allows the sex of found jaws to be determined at ages above eight years. The growth of the teeth is described. Both canines and incisors show well-marked sex differences in growth rate and size. The post-canine teeth do not show sex differences. Cycles of growth, wear and resorption of these teeth are discussed and it is concluded that mechanical senescence of the teeth is a major factor in mortality at ages above 30 years. Growth in body length is briefly discussed and provides further confirmation of the validity and precision of the age criteria. Growth equations are presented. Finally a survivorship curve derived from the ageing of 207 jaws assumed to represent natural deaths is presented. Population models are constructed from the survivorship curves by calculation of estimated natality rates (obtained by applying data on age at first breeding and annual pregnancy rate to the survivorship data) and life tables are constructed. The shape of the survivorship curve and the percentage recruitment agree with expectation and provide further evidence of the consistency of the age criteria.

When plant storage tissue is cut into thin disks it rapidly develops a high capacity to absorb phosphate from dilute solutions. The recent trend has been to attribute the development of this ability to the increased metabolic activity of bacteria known to be containing the tissue. Data presented in this paper shows that bacterial contamination of the tissue does contribute to the apparent uptake of phosphate by the disks. However, during the ageing process the number of bacteria decrease and therefore contribute less to the total uptake in the aged tissue. If the tissue is prepared and maintained in a sterile condition it is still able to develop a high capacity for phosphate absorption during ageing.

This paper is concerned with the integration of research on ageing with Eysenck's personality theory and in particular the personality dimension of introversion-extraversion. It is argued that older people behave like extraverts on a number of laboratory tests but like introverts in their behaviour patterns. A solution is offered for these paradoxical tendencies.

The problem of separating the effects of secular trend and age-associated loss on adult stature was investigated by using tibia length as a reference. Anthropometric stature and radiogrammetric tibia measurements were made on 288 Southwestern Ohio adults. Estimated statural loss was calculated by use of regression equations for the age of maximum statural attainment and age specific tibia lengths. To test the validity of the approach, these results were then compared with actual longitudinally-derived statural loss values for females in the same population. Measured and estimated loss values were in good agreement and it is suggested that the method proposed in this paper can be a useful tool in partitioning the statural variation due to secular trend and ageing in adult cross-sectional surveys.

In the young, to what extent can sequelae of ageing be delayed? In the adult, among whom degenerative conditions or diseases are already clearly apparent, can these changes be slowed down, or even arrested? Still further, if heroic endeavours be made, is it all feasible to put the clock back a little and cause stigmata to regress? These questions have occupied man’s contemplation, imagination, and ingenuity since early times, when the desire for long life was very much heightened because of its brevity from famine, pestilence and war. Down through the ages, the search for an “elixer of life” by alchemists and others was vigorously pursued. In our generation, ageing and its diverse ramifications have been studied extensively, especially by experiments on animals. The results of observations have been discussed and speculated upon in numerous papers, reviews, books, symposia, and seminars.

All men are mortal and nowadays an increasing proportion are being given the opportunity to die a natural death, which could be defined as one which is preceded and eventually provoked by the increasing vulnerability of old age. Everyone resents old age to some degree and the myth of an elixir of youth has been extant for centuries. Every advance in medicine and biology in the last hundred years has been scrutinized for its bearing on the understanding of senescence and the amelioration of the indignities of old age. In the field of microbiology and immunology, Metch-nikoff was preaching the virtues of changing the bacterial flora of the large bowel in the 1890s and the most recent discussion of genetic and immunological aspects of ageing is probably in a paper of mine published in August 1970.

Szent-Gyorgi and coworkers reported the existence, in various vegetable and animal tissues, of cellular growth inhibitors, glyoxal derivatives with the general formula R-CO-CHO. They appear to act by way of an interference with protein synthesis, by forming a bound between the inhibitor and -SH groups of cellular compounds essential to normal protein synthesis. In the present paper we investigated the inhibitor concentration in the liver and brain of rats as a function of age and of treatment with Folcysteine, which release in the body active -SH groups. Our results indicated significant differences between the concentration of the inhibitors in the hepatic tissue of rat of different ages. In old animals the concentrations are about 62 percent greater than in young. In brain, the inhibitor concentration differences are much smaller, but still significant. This phenomenon might be involved in protein synthesis modification in old age and in a biochemical mechanism of the ageing process.

introduction The secretions of the thyroid gland tend to accelerate skeletal ageing while lack of the secretions tends to retard this ageing (Silberberg and Silbergerg, 1943, and others). The time of appearance of secondary ossification centers, a stage of skeletal ageing, seems to agree with this concept, for such centers are accelerated in their appearance in rats injected with thyroxin (Noback, Barnett and Kupperman, 1949) and delayed in their appearance in thiouracilinjected rats (Noback, Barnett and Kupperman, 1949), in human cretins (Means, 1937; Caffey, 1945; Albright, 1947; and others), and in thyroidectomized rats (Scow, Becks, Simpson, Asling and Evans 1948). The purpose of this paper is to consider the relation of the thyroid gland to the time of appearance of primary ossification centers of membrane and cartilage bones (which only appear during prenatal life) in rat fetuses.

In recent publications ( Bailey et al 1969 ; Bailey & Shimokomaki, 1971 ) we have reported studies of the age-related changes in the reducible cross-links of several types of collagens. It was shown that with all the tissues studied there was a decrease with age in the amounts of all these intermolecular cross-links, presumably by conversion of the aldimine bond to a more stable non-reducible form. Since these changes inversely paralleled the rate of growth, the process was considered an essential step in the maturation of collagen. In addition, it was found that two of the reducible components, designated Fraction A, increased with age. This phenomenon was apparent not only in the different tissues examined, but also in different species of animal and in man. Thus, an increase in Fr. A appears to be a general characteristic of ageing and it was for this reason that further studies of the nature of these components have been carried out. This paper briefly describes their isolation and identification from mature bovine skin.

Summary. The influence of age on fertility was investigated in male and female C57/BL Icrf a' mice, ranging in age from 1\m=1/2\to 30 months. In males, the number of litters sired declined after about 24 months but there was no significant change in litter size. Most mice over 24 months old were sterile. The oldest male to sire a litter was 31 months old. The litter size in females followed the accepted pattern, declining from about 8 months: most mice were sterile by 12 months and the oldest mouse to produce a litter was 16 months old. The decline in fertility with increasing age in the female is well established (e.g. Jones & Krohn, 1961) but there is little information on the effects of age on breeding performance in the male. Although there is some evidence of declining fertility in bulls (Bishop, Campbell, Hancock & Walton, 1954), Finn (1964), using a non-inbred mouse strain (TO) found that the age of the sire had no significant effect on fertility as measured by litter size. In the present paper, the effects of age on the number of litters and on litter size in a colony of ageing mice are described. The mice used were C57/BL Icrf a', a mutant sub-line of C57BL mice established by Craigie (personal communication) in 1958 and since maintained in the ICRF laboratories. The mice were housed in pairs in an artificially lighted room (12 hr light and 12 hr darkness) and fed on a commercial pelleted diet (GR/R/3EK, Dixon's, Ware). Tap water was freely available. Five groups of males, 5, 18, 20, 24 and 30 months old, were used. Each was paired with a female of proved fertility. If the female died or became ill, it was replaced. The ages of the fifty-one females used ranged from 6 weeks to 7 months (eleven were 6 weeks old, seven were 3 months old, twenty-two were 4 months old and eleven were 5 to 7 months old). Three additional groups, each of six females aged 10, 17 and 25 months, were also used. These were paired with males of proved fertility, aged 7 months. The results are given in Tables 1 and 2. Table 1 gives litter size, number of litters and interval between litters for each group of males. To avoid the possible effects of declining fertility in the female, only the figures for the first 4 months of the breeding period are given. Litter size was not influenced by season. The oldest male to sire a litter was 31 months of age. Table 2 gives the litter size by

A recent analysis of blood pressure measurements collected during longitudinal studies of samples of the general population in South Wales suggested that ageing plays no direct role in determining blood pressure levels (Miall and Lovell, 1967). The increases in blood pressure occurring during intervals of 8 to 10 years were found to be significantly related to the average pressure attained?the higher the pressure the greater the increase in pressure in a given time? and were only indirectly related to age. One possible explanation for this finding, though not the only one, would be that above certain levels the pressure itself determines the subsequent rate of increase in pressure. Such a concept is generally accepted within the range of pressures which is designated as malignant hypertension. If it were found to be true also at lower levels, the hypothesis that a self-perpetuating mechanism is involved would require the influence of other factors to initiate the vicious circle. One such factor could be body weight. Alternatively, the relation between change in pressure and attained pressure might itself be due to an underlying dependence of change in pressure on body weight. In this paper we report further analyses in which we have explored the relationship between blood pressure, weight, and body build in subjects in the same two studies in Wales.

Ohnishi and Ohnishi (1962 a) have recently isolated from liver mitochondria a protein characterized by an ATPase activity and by physical properties similar to those of the actomyosin of muscle ( Ohnishi & Ohnishi 1962 b ). They suggested that this “contractile protein” constitutes part of a mechano-enzyme system in mitochondria which could be responsible for the swelling-contraction cycle occurring in these particles ( Lehninger, 1962 , Lehninger, 1962 ). It appeared desirable to repeat the experiments of Ohnishi and Ohnishi and to determine if the “contractile protein” possessed a specific activity in the mitochondrial swelling-contraction cycle. Experiments reported in this paper show that the protein fraction extracted from rabbit- or rat liver mitochondria according the procedure of Ohnishi and Ohnishi (1962 a) possesses some but not all of the properties of skeletal muscle actomyosin. However, this protein fraction was found to restore the ATP-induced contraction in mitochondria which had lost that property either after extraction by 0.6 M KCl or after ageing at 0° in isotonic sucrose.

The effect of ageing is studied for self-quenching GM counters of differently combined electrode diameters. The results obtained show that: 1) the basic factor contributing to the ageing of a counter is the change of the anode surface area; 2) this change appears in the discharge zone and is developed in three consecutive stages; (a) appearance of a fine powder, (b) appearance of spikes and flakes, and (c) formation of granules situated almost evenly along the anode length. 3) The anode surface could be brought to a state corresponding to a given stage, either through a definite number of recorded pulses, or by a certain intensity of the field, i.e., the change is dependent on the momentum of the products attacking the anode. The investigations are carried out with the purpose of confirming the role of the anode found in our previous papers - this role is basic for the operation of the counter.

This volume contains a miscellany of papers and the group discussions that followed them at the fifth Ciba Colloquium on Aging. Among the topics presented are the effect of parental age on the longevity of man and of racehorses; aging in bees, Drosophila, and other insects; aging in fish, both in nature and in captivity; the lifespan of and arteriosclerosis in birds; and the relation of the age of onset of degenerative disease to the lifespan of the rat and of man. It is, however, in the group discussions that the greatest interest lies. Through these discussions attention is drawn to the tremendous gaps in the knowledge of aging, which handicap man's attempts to postpone and ameliorate senescence. Important problems of the study of aging are those of time and cost; many experiments, to be conducted properly, need 30 to 100 years of research before conclusive data can be collected

M. NAVASHIN1 and his co-workers reported in a series of papers that plants produced from old seeds in Crepis show a great percentage of mutations. Similar observations were reported by Cartledge and Blakeslee2 and by Peto3 in America working with various plants. They confirmed the results found by Navashin and his co-workers. All these authors state that Navashin made this discovery. Hugo de Vries, however, in his “Mutationstheorie” (1901)4, reported that in one case five-year old seeds from Oenothera gave 40 per cent instead of 5 per cent mutations (p. 185). He interpreted this phenomenon by postulating a longer viability of the mutated seeds (p. 186).