西安市青年学生胸骨长与身长的关系

本文对1980年测量的西安在校汉族青年学生1585名(男863,女722),年龄16-24岁,按年龄性别分组,计算了身长和胸骨长的均值、胸骨长占身长的百分数、身长与胸骨长的比值、身长、胸骨长指数,并提出了由胸骨长推算身长的回归方程。     

青年猫和老年猫视神经超微结构观察比较

目的探讨青年猫和老年猫视神经年龄相关的形态学变化及可能造成的生理影响。方法取4只青年猫(2-3岁,2-2.5kg)和4只老年猫(10-13岁,2.5-3.5kg)颅内相对应部分视神经,制作横向半薄切片和超薄切片,半薄切片用甲苯胺蓝硼砂溶液染色,光镜观察、测量视神经的直径(不含外层神经膜);超薄切片标本用醋酸和柠檬酸铅染色,电镜观察、计数视神经纤维密度、测量视神经纤维外径D(含髓鞘)和内径d(不含髓鞘),按一定分级范围算出各种直径的纤维及各种d/D比值的纤维所占百分比,分别画出直方图,对实验结果进行统计学分析并绘制纤维直径谱。结果与青年猫相比,老年猫视神经直径显著增大(P0.05);纤维数量显著下降(P0.05)。纤维直径谱分析结果显示,青、老年猫纤维直径分布范围相似,但老年猫纤维的峰直径及纤维平均直径比青年猫的显著减小(P0.05),老年猫视神经纤维的d/D比值亦明显降低。另外,老年猫视神经中部分轴突肿胀,髓鞘疏松、结构紊乱,板层脱离、空泡化,有的轴索髓鞘溶解。结论在衰老过程中,老年猫视神经纤维丢失,纤维直径减小,d/D比值下降,以及纤维髓鞘的松散解体,这些变化均可能导致视神经纤维对视觉信息的传导速度减慢,是老年个体视觉分析速度下降的重要原因。     

福建和溪亚热带雨林地表微生物的数量动态

分枯枝落叶层、腐解层和表土层（0—20cm深）三个层次研究福建和溪亚热带雨林的细菌、真菌和放线菌三大微生物类群的数量和月变化。结果表明：三个层次的微生物数量均以细菌最多,次为真菌,后为放线菌。比较三个层次,各微生物类群在各月份都是枯枝落叶层和腐解层数量较多。同一微生物类群在三个层次的数量均有明显而相似的季节变化;不同类群变化规律不尽相同,但基本只有一个高峰。细菌的高峰值在4月份,真菌约滞后一个月在5月份,放线菌则在8月份才出现高峰。各层次的细菌数和真菌数与月凋落物量、月降雨量和月平均气温各有显著的线性正相关（p＜0．01或0．05）,而放线菌则仅与月平均气温显著相关。     

THE NUMBER AND DISTRIBUTION OF PHYSICIANS IN CALIFORNIA

The ratio of physicians to general population in California has been approximately the same for many years, the influx of physicians having kept pace with the population trend.For many years California has licensed more physicians than any other state.The five medical schools in this state have been increasing the number of candidates admitted to the freshman class. Attempts are being made to increase the number of medical schools in this state to seven in anticipation of the future growth and medical needs of the population.The heaviest concentration of physicians is as always in the thickly populated areas as determined by the population physician ratio.A study of the detailed statistics presented in this paper should be of interest to all California physicians.     

CHANGES WITHIN METABOLIC COMPARTMENTS IN THE BRAINS OF YOUNG RATS INGESTING LEAD

—[2-¹⁴C]Glucose and [³H]acetate were injected simultaneously into 19-day-old rats suckling from mothers fed either a normal diet or a diet containing 4·5% lead acetate. Changes in the rate of conversion of both precursors into amino acids associated with the tricarboxylic acid cycle were observed. [^I4C]Glucose. In the brain of young rats ingesting lead, the specific radioactivity of glutamate, aspartate, γ-aminobutyrate and glutamine were all significantly lowered relative to that of glucose. Glutamine labelling was the most affected. [³H]Acetate. In comparison with controls, the total amount of ³H in either water or acid-soluble constituents of the brain was the same, but the ³H content of the amino acids was significantly reduced in the lead-treated rats. In both groups, glutamine had the highest specific radioactivity but the time courses of the labelling of glutamine were different. In the control the peak incorporation was reached during the first 5 min, whereas in the experimental animals this occurred at about 10 min after the injection of the precursor, and the specific radioactivity even at that time was less than in controls. When compared with controls, the depression in the labelling of glutamine was accompanied at 5 min by an increase in the specific radioactivity of aspartate. In the lead-treated rats the labelling of GABA was also slowed and the time course seemed to follow that of glutamine rather than glutamate. In spite of the differences in the metabolism of [³H]acetate, metabolic compartmentation of glutamate, assessed by a glutamine : glutamate specific radioactivity ratio higher than 1, was evident even in the brain of the lead-treated animals, although the values of the ratio at 5 and 10 min were less than in controls. There was no evidence of a diminished supply of substrates to the brain in lead intoxication. The overall changes would be consistent with a retardation in the biochemical maturation of the brain in terms of development of glucose metabolism and metabolic compartmentation.     

GROWTH OF THE BARLEY COLEOPTILE. I. ITS RELATIONSHIP TO CELL NUMBER AND LENGTH IN NORMAL AND γ-IRRADIATED SEEDLINGS

The number of cells per vertical column in barley coleoptiles differs in various growth classes; it is highest in tall coleoptiles, intermediate in medium ones, and lowest in short ones. In those that elongate early and grow rapidly, cells per column increased from 88–218 between 12 and 44 hr after the seeds were placed on water; in short coleoptiles they increased to only 85 per column after 115 hr because elongation and division are restricted in these. Cell number does not increase in coleoptiles from seeds irradiated with 250 krad. Variation in the growth pattern of irradiated coleoptiles was similar to that of normal ones, although the range in lengths was reduced. Although the number of cells is much higher in tall controls than in irradiated coleoptiles, the latter can become tall; therefore an increase in cell number during germination does not seem to be a prerequisite for tallness. Coleoptiles 32 mm long, from irradiated seeds, have the same number of cells per column as the shortest ones (6 mm) after 119 hr.     

VARIATION IN NUMBER OF APICAL RAMIFICATIONS AND VEGETATIVE CELL LENGTH IN FRESHWATER POPULATIONS OF CLADOPHORA (ULVOPHYCEAE,CHLOROPHYTA)1

Populations of Cladophora with two different levels of ploidy, n = 18/2n = 36 (18/36) and n = 24/2n = 48 (24/48), are present in creeks in the southern part of the province of Buenos Aires, Argentina. The goals of our study were to 1) relate the number of apical branches · mm^?2 in 18/36 and 24/48 populations with the water velocity at the collection site; 2) correlate the number of apical ramifications · mm^?2 in plants of the same population (24/48) growing in sectors with distinct water velocities; 3) compare cell length among populations with different ploidy levels, analyzing the sources of variation in different sectors of the same creek and in different plants of the same sector; and 4) analyze the sources of variation in cell length in 24/48 populations, including variations among different creeks. Our results suggest that 1) the number of branches · mm^?2 tends to increase with higher water velocity; 2) the 24/48 populations have more ramifications · mm^?2 than the 18/36 ones; 3) the length of vegetative cells is not an adequate criterion for differentiating between 18/36 and 24/48 populations; and 4) variations in vegetative cell length in 24/48 populations are highly significant among plants from different sectors of the same creek.     

CHANGES IN THE ANAEROBIC THRESHOLD IN AN ANNUAL CYCLE OF SPORT TRAINING OF YOUNG SOCCER PLAYERS

The aim of the study was to assess changes in the anaerobic threshold of young soccer players in an annual training cycle. A group of highly trained 15-18 year old players of KKS Lech Poznań were tested. The tests included an annual training macrocycle, and its individual stages resulted from the time structure of the sports training. In order to assess the level of exercise capacities of the players, a field exercise test of increasing intensity was carried out on a soccer pitch. The test made it possible to determine the 4 millimolar lactate threshold (T LA 4 mmol · l^-1) on the basis of the lactate concentration in blood [LA], to establish the threshold running speed and the threshold heart rate [HR]. The threshold running speed at the level of the 4 millimolar lactate threshold was established using the two-point form of the equation of a straight line. The obtained indicators of the threshold running speed allowed for precise establishment of effort intensity used in individual training in developing aerobic endurance. In order to test the significance of differences in mean values between four dates of tests, a non-parametric Friedman ANOVA test was used. The significance of differences between consecutive dates of tests was determined using a post-hoc Friedman ANOVA test. The tests showed significant differences in values of selected indicators determined at the anaerobic threshold in various stages of an annual training cycle of young soccer players. The most beneficial changes in terms of the threshold running speed were noted on the fourth date of tests, when the participants had the highest values of 4.01 m · s^-1 for older juniors, and 3.80 m · s^-1 for younger juniors. This may be indicative of effective application of an individualized programme of training loads and of good preparation of teams for competition in terms of players’ aerobic endurance.     

THE LEAF OF CALYCADENIA AND ITS GLANDULAR APPENDAGES

Carlquist , Sherwin . (Rancho Santa Ana Botanic Garden, Claremont, Calif.) The leaf of Calycadenia and its glandular appendages. Amer. Jour. Bot. 46(2) : 70-80. Illus. 1959.—Large tack-shaped glands are characteristic of the leaves of Calycadenia which are associated with the inflorescence. These glands may be divided into those which are terminal on leaves and those which occur laterally on the surface of the leaf. Lateral glands show stages early in their development which are identical with those of simpler trichomes of Madinae. Terminal glands, which possess more vascularization of the stalk, show a more modified form of development. Vascularization is not derived from protoderm, but from more deeply-seated cells. These cells are included in a zone of elongation which forms the stalk. Vascular bundles may extend to the base of glands which lack vascularization in their stalks. Tack-shaped glands are considered an advanced form of trichome in which internal tissues of the leaf are involved. Within the genus Calycadenia, ontogenetic and comparative studies suggest that the following characters are advanced: reduction to a single terminal gland, “inrolling” of margins to form a cylinder of bundles, concomitant with a central core of fibers or a pectic channel. Systematic distribution of gland occurrence and of types of foliar structure are given.