Middle Developmental Stages Research Articles

リンゴ果実の発育に伴うカテキン類およびプロシアニジン類の含量・組成の変化

リンゴ'つがる'および'ふじ'の果肉のカテキン類, プロシアニジン類および数種の主要フェノール物質を比色法, TLC法およびHPLC法により分析し, 果実の発育中の含量・組成の変化を調べた.1. 両品種の果肉のポリフェノール成分はプロシアニジンポリマーが最も多く, 酢酸エチルで抽出される比較的低分子のフェノール物質においては, 主要な成分はクロロゲン酸, 他のヒドロキシ桂皮酸エステル類, (+)-カテキンおよび(-)-エピカテキン, プロシアニジンオリゴマーおよびフロリジンであった.2. 受粉後30日(以下, 30 DAP)から成熟期にかけての果実肥大に伴い, 果肉100gFW当たりのカテキン類とプロシアニジン類の総量(総カテキン単位含量)は減少したが, 1果当たりの総カテキン単位含量は両品種ともに果実発育中に増加した.3. 30 DAPの果実におけるカテキン・プロシアニジン類の構成は両品種ともにオリゴマーは少なく, 単量体とポリマーの占める割合が高かった.また, 両品種ともに1果当たりのカテキン単量体およびプロシアニジンオリゴマー含量は果実発育中期に多くなり, 以降, 成熟期にかけて減少し, ポリマーについては成熟期まで増加する傾向が認められた.4. 品種間差異として, 'ふじ'においては(+)-カテキンおよびプロシアニジンB1の含量が'つがる'に比べてやや多く, また, 'ふじ'は'つがる'よりクロロゲン酸含量が顕著に多く含まれ, 発育中に増加した.以上より, リンゴ'つがる'および'ふじ'果実のフェノール物質は組成成分の含量に若干違いが認められたが, 両品種ともに発育中においてカテキン・プロシアニジン類が生合成され, 発育中期には単量体およびオリゴマーが増加し, これらの成分は成熟期にかけてプロシアニジンポリマーに変化するものと考えられた.

Communication and the evolution of ecosystem

In the theory of natural evolution, the evolution of ecosystem took up the middle stage of development. Prior to this was a long but simple physical evolution and following that has been the complex and rapid social evolution. Research in the different stages of evolution used to concentrate on different fields separately whereas today the study of general evolution is conducted by a comprehensive way that transcends different fields of studies. One of them is the practice of dealing evolution and development in various spheres in the light of information and communication. The concept of information and communication was first put forth by C. E. Shannon in 1948 in his mathematical and stereotypical concepts, the primary aim of which was a fundamental theoretical study of the communication technology of the human society. People then were scarcely aware of its extensive influence and tremendous development later. When we today look at the history of the natural and ecological evolution from an entirely new angle, it is not difficult to find an evolutionary history of information and communication along with the natural evolution and that in ecological evolution, information and communication are no longer dependent variables modified and propelled by the independent variable of natural evolution. On the contrary, it has begun to act a new role of evolution, or we may say that information and communication are taking up a “master's” position in the evolution of the ecosystem.

Heart rate in developing ostrich embryos

1. A non-invasive condenser microphone was used to detect cardiogenic, acoustic pressure changes (acoustocardiogram, ACG) over the eggshell in order to determine embryonic heart rate (HR) of ostriches in a commercial hatchery. 2. HR measured for 36 eggs at 36.3C was maintained at about 185 bpm during the middle stage of development (days 19 to 23) and then decreased with embryonic development. 3. The daily changes in HR were not related to egg mass, but HR of high water vapour conductance (GspH2O) eggs was found to decrease less during the last stages of incubation relative to low and medium GspH2O groups. 4. The averaged HR at 80% of incubation period was close to the value predicted from the allometric equation determined previously for embryos of domesticated precocial birds.

Multiple Equilibrium, Variability, and the Development Process

Per capita output is more volatile in middle-income economies than in both low-income and high-income economies. In this paper, we address this fact in a two-periods overlapping generations model with two productive sectors (a developed sector and a subsistence sector) and a credit sector. In the second period, agents can choose to operate the developed technology. To do so, they can borrow resources to pay an entry cost. Due to the presence of an extemality in the developed sector, as the fraction of managers in this sector increases, its productivity also increases. We show that, if the model economy is in the early or in the mature stages of development, there is a unique equilibrium. However, when the economy is in the middle stages of development, multiple equilibrium arise since the extemality affects the performance of the credit market. The multiplicity of equilibria disappear when the credit market is perfect or it does not exist. Moreover, we fmd that in economies with imperfect credit markets, per cap ita output volatility tends to be higher than in economies with perfect or non-existent credit markets.

Multiple Equilibrium, Variability, and the Development Process

Per capita output is more volatile in middle-income economies than in both low-income and high-income economies. We examine this pattern in a two-period overlapping generations model with two productive sectors (a developed sector and a subsistence sector) and a credit sector. In the early and mature stages of development, there is a unique equilibrium, because labor and credit markets are cleared by a unique set of prices. In the middle stages of development, however, the model shows that markets can be cleared by a multiple set of prices. This multiplicity of equilibria arises as productive externalities are reflected in credit markets.

Compartments and appendage development in Drosophila.

The appendages of Drosophila develop from the imaginal discs. During the extensive growth of these discs cell lineages are for the most part unfixed, suggesting a strong role for cell-cell interactions in controlling the final pattern of differentiation. However, during early and middle stages of development, discs are subdivided by strict lineage restrictions into a small number of spatially distinct compartments. These compartments appear to be maintained by stably inheriting states of gene expression; the compartment-specific expression of two such 'selector'-like genes, engrailed and apterous, are critical for anterior-posterior and dorso-ventral compartmentalization, respectively. Recent work suggests that one purpose of compartmentalization is to establish regions of specialized cells near compartment boundaries via intercompartmental induction, using molecules like the hedgehog protein. Thus, compartments can act as organizing centers for patterning within compartments. Evidence for non-compartmental patterning mechanisms will also be discussed.

Immunohistochemical studies on the development of the hypothalamo-hypophysial system in Xenopus laevis.

Few attempts have been made to clarify the relational development of the hypothalamo-adenohypophysial and -neurohypophysial systems in species higher than amphibians. The appearance and topographical distribution of endocrine and neuroendocrine cells and fibers in these systems were immunohistochemically examined in the larvae of Xenopus laevis from immediately before hatching (stage 32, Nieuwkoop and Faber's classification) to the end of metamorphosis (stage 66). (1) Each endocrine cell differentiated until the middle premetamorphic period. MSH cells initially appeared in the posterior half of the pituitary anlage at stage 35/36, followed by the differentiation of GH cells at stage 39 in the middle part, PRL cells at stage 46 in the anterior half of the pituitary anlage, and LH cells at stage 50 in the posterior two thirds of the pars distalis. With the progression of development, the cells which differentiated at early stages shifted from their initial positions; MSH cells, to the pars intermedia; and GH cells, to the posterior half of the pars distalis. 2) Oxytocin and vasopressin fibers were observed at stage 47/48 in the median eminence, and converged to the pars nervosa at later stages. 3) Neuroendocrine fibers innervated the median eminence during the middle premetamorphic to prometamorphic period: SOM fibers, at stage 45; CRH, 47/48; GRH, 48; dopamine, 58; and LHRH, 60. The cells containing these hormones were observed in the (presumptive) preoptic and/or infundibular nuclei. These results suggest the following three chronological steps in the development of hypothalamo-hypophysial systems and their target organs: independent development of target organs at early developmental stages; appearance of hypophysial hormones to control the development of target organs at middle developmental stages; appearance of hypothalamic hormones to control the function or maturation of the hypophysis at late developmental stages.

Embryonic Heart Rate in Altricial Birds, the Pigeon (Columba domestica) and the Bank Swallow (Riparia riparia)

Ballistocardiography or impedance cardiography was used to measure on a daily basis the heart rate (fH) of embryos of altricial pigeons (Columba domestica) and bank swallows (Riparia riparia). The patterns of fH changes during development were investigated. Embryonic fH of domestic and homing pigeons increases slowly during the middle stages of development and then increases sharply toward the end of incubation. Fantail pigeons show a diferent pattern of embryonic fH change; that is, fH remains constant until 1-2 d prior to external pipping and increases thereafter. Heart rate of the bank swallow increases continually throughout the last half of the incubation period. The developmental patterns of fH changes in pigeons and swallows generally are diferent from those of most precocial birds, in which embryonic fH decreases during the last stages of prepipping development.

ORCHID?A computer simulation of the reliability of an NDE inspection system

CANDU pressurized heavy water reactors contain several hundred horizontally-mounted zirconium alloy pressure tubes. Following a pressure tube failure, a pressure tube inspection system called CIGARette was rapidly designed, manufactured and put in operation. Defects called hydride blisters were found to be the cause of the failure, and were detected using a combination of eddy current and ultrasonic scans. A number of improvements were made to CIGARette during the inspection period. The ORCHID computer program models the operation of the delivery system, eddy current and ultrasonic systems by imitating the on-reactor decision-making procedure. ORCHID predicts that during the early stage of development, less than one blistered tube in three would be detected, while less than one in two would be detected in the middle development stage. However, ORCHID predicts that during the late development stage, probability of detection will be over 90%, primarily due to the inclusion of axial ultrasonic scans (a procedural modification). Rotational and axial slip could severely reduce probability of detection. Comparison of CIGARette's inspection data with ORCHID's predictions indicate that the latter are compatible with the actual inspection results, though the numbers are small and data uncertain. It should be emphasized that the CIGARette system has been essentially replaced with the much more reliable CIGAR system.

Effect of Soil Moisture on Oviposition, Water Absorption, and Survival of Southern Masked Chafer (Coleoptera: Scarabaeidae) Eggs1

Eggs of Cyclocephala immaculata Olivier absorb water from the soil, increasing ca. threefold in weight during the first 10 days of embryonic development. Eggs developed normally at soil moistures of 12.5% and above, but shriveled and died in drier soils. Length of incubation period, survival, and final egg weight did not differ at soil moistures within the range required for survival; however, few eggs were laid in dry soil or when soil moisture approached field capacity. Oviposition in soil moisture gradients indicated that the depth at which eggs are laid can vary in response to moisture levels. The chorion of the egg is covered densely and uniformly by minute tubercles, but specialized hydropyles are absent. The eggs are most susceptible to desiccation when newly laid or close to hatching, but are relatively resistant during the middle stage of development. These differences are associated with changes in the thickness of the serosal cuticle.

Starch and total water-soluble carbohydrates in the developing fruits of early- and late-maturing peach cultivars

SummaryMore starch and total water-soluble carbohydrates accumulated in the whole fruit and flesh of cv Sharbati (late) than in cv Flordasun (early). Whereas the starch content increased progressively in Flordasun flesh throughout development, it declined markedly in Sharbati flesh during the middle developmental stage. The total watersoluble carbohydrates decreased during this stage in the whole fruit and the flesh of both cultivars.

Respiration and ripening patterns in the life cycle of the mango fruit

SummaryAlphonso mangoes picked at any stage of maturity (starting from fruit-set) and stored at room temperature show typical respiratory changes characteristic of a fully matured mango. Fruits picked during the earlier and later stages of development show respiration climacteric within 6–10 days. During the middle stages of development the preclimacteric trough continues to extend and the climacteric occurs after 10 days. Fully mature, tree-ripe mangoes do not show a respiratory climacteric during post-harvest storage.Chemical constituents, such as titratable acids, apparent ascorbic acid, carbohydrates and carotenoids, estimated both at harvest and in ripe fruits from different pickings show changes similar to those characteristic of a fully matured ripening fruit.Possibilities of reducing losses from pre-harvest fruit drop and post-harvest decay by resorting to early harvesting are discussed.

Respiratory properties of chicken embryonic blood during development

Blood P O 2 , P CO 2 and pH and Hct of chorioallantoic vein and artery in chicken embryos were simultaneously measured, and [HCO 3 −3], total-CO 2 content in plasma and base excess were determined graphically by plotting P CO 2 , pH and calculated Hb on the Siggaard-Andersen alignment nomogram. The experiment was carried out daily from the eighth day of incubation to the 18th day. P CO 2 , [HCO 3 −], CO 2 content and base excess gradually increase with time, while blood P O 2 and pH decrease during development. The differences of these parameters between vein and artery are rather large in comparison with those in the adult human being; especially they are large in the middle stage of development and they become small with time. The changes in respiratory parameters determined have close correlation with the developing embryonic weight. It is suggested that the embryo encounters respiratory alkalosis with metabolic acidosis in the middle stage of development, and then the acid-base status approaches normal level with time.

Development of oil in the seed of Asclepias syriaca L.

Seed of Asclepias syriaca L. was gathered at intervals during the growing season. Analyses of the seed, the oil, and the fatty acids were made, the latter by gas chromatography. About 75% of the total oil was formed in the first 5 weeks after flowering and the remaining 25% over the final 7 weeks. There was a sudden change in fatty acid composition at a middle stage of development, resulting in a fall in the percentage of hexadecenoic and octadecenoic acids and a rise in linoleic acid. Thereafter the changes were small except that linoleic showed a further increase in proportion to the total fatty acids.The weight of individual fatty acids per 1000 seeds was calculated at each stage of development. Corresponding to the change in percentage composition, there was a sharp increase in the weight of linoleic acid per 1000 seeds and an actual decrease in the weight of hexadecenoic and octadecenoic acids, between the 5th and 7th week after flowering. Between the 7th week and maturity, linoleic acid increased considerably, hexadecenoic and octadecenoic acids increased slightly, and the others remained unchanged in amount. There was a net loss of hexadecenoic acid from the 5th week to maturity. It is postulated that 9-hexadecenoic acid was converted in the seed to 11-octadecenoic acid and that oleic acid was converted to linoleic acid.

THE DISTRIBUTION OF TIN-ORE DEPOSITS WITHIN FOLDED ZONES

The author makes an attempt to establish the general laws governing distribution in time and position of tin-bearing centers and areas in the course of the geological history of the earth; on the basis of methods of regional metallogenic analysis, developed in the U. S. S. R. by a group of scientists under the guidance of G. A. Bilibin. The author has considered the principal geotectonic and structural geological features and factors controlling the regular occurrence during a certain stage of development of a folded zone, of a certain type of tin-bearing intrusions and, hence, of a certain mineralogical-geochemical type of tin deposits. Considerable tin concentration evidently did not take place during the initial and early stages in development of folded zones. The middle stages of development, corresponding to the period of transformation of a geosyncline into a folded belt, were highly productive with regard to tin. Tin accumulations are associated with syntectonic batholithic intrusions of acid and ultra-acid “potassium” granites. Tin-bearing batholiths and their linear belts are controlled by regional ancient deepseated fractures, confined either to the points of anticlinorium contact (central upheavals) with the adjacent inner synclinoria or to the contact points of downwarpings with consolidated geoanticlinal zones. The late stages of development of geosynclinal regions corresponding to the period of consolidation of the folded territory also produced considerable tin concentrations. According to the depth of the controlling intrusions, the showings of tin occurrences belonging to the late stages of development are subdivided into two natural groups: the hypabyssal and the subvolcanic. Tin ore-bearing areas belonging to the late stages of development, are confined to the following two types of geotectonic environments: 1) the mobilized marginal parts of geosynclines in places of their contact with projections of platforms of intermediate massifs (blocks) and consolidated geoanticlinal structures. A number of large tin ore-bearing areas is confined to structures of late superimposed graben-like downwarpings (complicated by fractures) with a powerful development of terrestrial volcanism; 2) the inner portions of geosynclines, where the tinore-bearing areas are confined to structural facial zones of inner synclinoria, more frequently in places of contact of the latter with zones of central uplifts. The distribution of the world tin resources in the course of geological times is as follows: The Precambrian: 3. 3 percent (Nigeria, Rhodesia, Congo, Union of South Africa); The Caledonian folding: 6. 6 percent (Africa and Australia); The Variscian folding: 18.1 percent (Cornwall, Erzgebirge, the Pyrenees, Australia, Tasmania); The Kimmeridgian folding: 63.1 percent (South- Eastern Asia). Simultaneously with the growth of commercial tin concentrations from the Pre-Cambrian to the Mesozoic, complication of the nature of tin mineralization is observed; from tin-bearing pegmatites in the Pre-Cambrian to complex multicomponent deposits in the Mesozoic and the Cenozoic. Author

ON THE DEVELOPMENT AND STRUCTURE OF THE CELL WALL IN NITELLA

THE INTERNODE CELLS of the aquatic alga Nitella axillaris Braun provide unusually interesting material for the study of cell wall development. In about two weeks these cylindrical cells grow from microscopic size to a mature length greater than 2 cm. The final diameter is about 0.3 mm. Throughout this growth the cylindrical surface of the cell is freely exposed to the aqueous medium; contact with the rest of the plant is made only at the ends of the internode cell (fig. 4). This report will present structural information about these walls and relate this information to other descriptive facts of wall development in Nitella. The growth pattern of the cell surface has been described (Green, 1954). If a longitudinal row of small evenly-spaced marks is placed on a young cell, the marks will be displaced by the growth of the cell. The marks become distant from each other in a way which demonstrates an essentially even distribution of elongation. Since the wall is at all times a right cylinder, increase in girth must also be evenly distributed along the cell axis. The row of marks, while maintaining its regularity, is transformed into a helical configuration as the wall elongates, hence a type of spiral growth is found in this cell. The twisted state of any cell may be quantitatively determined from an examination of the two striations which are representative lines of twist. The striations are visible in the living cell as colorless streaks in an otherwise uniform green layer of stationary chloroplasts just interior to the wall. These striations are 1800 apart on the cell surface and each forms a regular Z-spiral helix (the striation en the near surface of an upright cell being parallel to the diagonal of an upright letter Z). This helix is also termed dextral. Each striation is almost parallel to the cell axis in the very young cell; the angle between a striation and the cell axis can become as great as 30? during the middle stages of development; the angle with the cell axis (/3) decreases to about 5? as maturity is reached. This normal development is diagrammed in fig. 4. Cells which cease to grow while in the highly twisted form maintain their twist permanently. Compressing or stretching such cells does not noticeably alter the twist. Further, growing walls in the twisted state show only a barely detectable