降水量下限引种区沙地樟子松幼林种群树高分布偏斜度和不整齐性

对降水量下限引种区沙地樟子松自然稀疏前人工林种群树高分布偏斜度和不整齐性的研究表明,种群高生长的不整齐性和分布的不对称性在林分自疏前随着林分发育而下降,造成高生长事整齐性变化的因素主要有年龄,初始生长状况,种群密度,对土壤水分的竞争和沙丘部位的差异;沙丘部位对林分不整齐性的影响作用要大于密度。     

Height and weight growth patterns of school age deaf children

Distance and velocity curves for height and weight were analyzed in a mixed longitudinal sample of American White, American Negro and Mexican-American deaf children 6 through 17 years of age. The heights of deaf boys and girls are, on the average, consistently below an accepted pediatric standard from six through ten years of age. Between 11 and 17 years, deaf White and Negro boys approximate the standard, while White and Negro girls are at or slightly below the standard. Deaf Mexican-American children are consistently below the height standard. For body weight, deaf boys are at or slightly below the standard from 6 to 11 years, and are at or slightly above the weight standard from 12 to 17 years of age. White and Negro deaf girls generally approximate the weight standard from eight years of age on. Mexican-American deaf girls are consistently below the standard until 13 years of age, while between 14 and 17 years they are at or above the standard. Height and weight velocity curves for deaf children parallel closely the incremental standards of Falkner ('62). The height velocity curve, however, appears to peak, on the average, about one year earlier in deaf children.     

Some secular changes in the growth of American-born and native Japanese children

Three hundred and sixteen (35%) of the American-born Japanese children whose height, weight, and skeletal age were recorded in 1956–57 were reexamined as young adults between 1968 and 1974, when they were found to be taller, heavier, and shorter legged than men and women in Japan who were born in the same years as they. These differences between the American-born and the native Japanese adults were relatively smaller than they had been during childhood, due to both an acceleration in the growth rate of the native Japanese and a concomitant decline in that of the American-born Japanese during the intervening years. A comparison of our 1956–57 data with Kondo and Eto's findings in Los Angeles in 1971 shows that there has been very little increase in the size of California-Japanese children since 1956. The curves of average heights of native Japanese children 6 to 20 years of age, at 10-year intervals from 1900 to 1970, disclosed the changing rate at which they grew during different decades of that period. Those curves and other data discussed in this paper provide additional evidence of the biological superiority of the human female as compared with the male.     

The evolution of adult height in Europe: A brief note

This paper presents new evidence on the evolution of adult height in 10 European countries for cohorts born between 1950 and 1980 using the European Community Household Panel (ECHP), which collects height data from Austria, Belgium, Denmark, Finland, Greece, Ireland, Italy, Portugal, Spain, and Sweden. Our findings show a gradual increase in adult height across all countries. However, countries from Southern Europe (Greece, Italy, Portugal, and Spain) experienced greater gains in stature than those located in Northern Europe (Austria, Belgium, Denmark, Finland, Ireland, and Sweden).     

Phenological features in relation to growth forms and biomass accumulation in an alpine meadow of the Central Himalaya

Phenological records of 50 plant species were made during 1988–89 in an alpine meadow (30° 10-30° 13 N lat. and 79° 39-79°-41 E long.) of Central Himalaya located between 3100–3750 m elevation. The growth initiation occurred when temperature began to rise continuously and the resulting in snowmelt. The peaks of the various phenophases succeeded one after another in time, within a period of about four months (from May to September) which is longer than the period reported for the alpine sites of higher latitudes. The period of growth initiation appeared to be related to growth form, the species showing earlier growth initiation (when temperatures were lower) deployed leaves to lower heights, close to the ground. A majority of forbs completed growth cycle earlier than the grasses. For example, one group represented by Trachydium roylei reached peak growth a few weeks before did another group of species, represented by Danthonia cachemyriana, which is indicative of niche separation of the respective group of species. Activities of accumulation of live and dead shoot biomass were clearly separated in time in most communities, the former occurring from May to August, and the latter mainly in September. Nomenclature: Osmaston (1926).     

The contribution of adrenal and gonadal androgens to the growth in height of adolescent males

Gonadal androgens are known to regulate the rate of growth in height during adolescence, particularly in males, but little is known of the role of adrenal androgens in this process. In a prospective multiple regression model we show that both adrenal and gonadal androgens contribute to the increasing rate of growth in height prior to peak height velocity and the decreasing rate of height growth in later adolescence. Since adrenal androgen secretion begins in mid-childhood, long before gonadal maturation and the secretion of testicular androgens, these findings may prove helpful in explaining population variation in adolescent growth.     

The Estimation of Skewness and Kurtosis of Random Effects in the Linear Model

Generalising the ANOVA method of estimating variance components in mixed linear models a simple procedure is presented to estimate skewness and kurtosis of the distributions of the random effects of the model. For the model II of a one-way classification this procedure is demonstrated explicitly.     

Quantitative changes in the frequency and distribution of the C-cell population in the rat thyroid gland with age

Summary The development of calcitonin cells (C-cells) was investigated in rat thyroid glands from birth to 120 days, using an immunoperoxidase technique and a point-counting method. The proportion of C-cells to follicular cells was 4.5% on the day of birth and increased progressively to 10.4% by 120 days. The highest density of C-cells was noted in the mid-region of the lobes along a longitudinal axis. The caudal and cephalic regions of the lobes contained smaller numbers of C-cells. The C-cells tended to be more numerous in the posterior aspects of the lobes. Although the numbers of C-cells in 120-day-old animals were markedly increased as compared to animals at the time of birth, the cell distributions within the glands were similar at all ages.     

Sexual dimorphism in the emergence of deciduous teeth: its relationship with growth components in height

Sexual dimorphism in the emergence of the deciduous dentition of French-Canadian children may be explained by differences in recumbent length. Relative to the chronological age scale, boys are longer and their teeth emerge earlier than girls. Recumbent lengths attained at the exact age of emergence, as estimated by fifth-order polynomials fitted to each subject's serial data, are comparable between the sexes. Multi- and univariate analyses of variance show no significant sex differences in the lengths attained at the age of emergence of the deciduous teeth. These findings suggest that clinical standards for emergence of deciduous teeth scaled relative to length rather than chronological age are more accurate and efficient.     

A new measure of growth efficiency: Skull base height

Skull base height increases significantly with better nutrition and health conditions, as seen in comparing 163 nineteenth to twentieth century dissecting-room skeletons (Terry Collection) with 237 modern American middle-class adults (forensic and willed skeletons). The increase parallels the change in pelvic inlet depth index, known to respond sensitively to nutrition, and in stature, and is over six times greater than the general skull size change. Skull base height (porion-basion) is easy to measure with depth gauge and sliding caliper, or by subtraction, and is in adults a sensitive indicator of childhood growth stress.     

Genetic dissection of height in maritime pine seedlings raised under accelerated growth conditions

Random Amplified Polymorphic DNAs (RAPDs) were used to investigate quantitative trait loci (QTL) for traits related to height growth on 126 F₂ seedlings of maritime pine (Pinuspinaster Ait). The haploid megagametophyte was used to determine the maternal genotype of each F₂ individual. The seedlings were raised for 2 years in a greenhouse under accelerated growth conditions consisting of intense fertilization combined with continuous light treatments. Total height was measured at different developmental stages, and height growth components were measured after the second growth period. QTLs were identified for each trait. For total height, QTLs of different developmental stages were located on distinct linkage groups. However, rather than a complete temporal change in QTL expression, our results showed that maturation may induce a progressive shift of the genetic control of height growth. This may provide an explanation for a low juvenile-mature phenotypic correlation previously reported for height. Height growth components related to the initiation (controlled by the apical meristem) and elongation of shoot cycles (controlled by the subapical meristem) were mapped to different chromosomes, suggesting that the activity of these meristems is controlled by separate genetic mechanisms.     

Economic disadvantage modifies the association of height with low mood in the US, 2004: The disappointment paradox

INTRODUCTION: Taller stature is associated with greater health potential reflected by reduced risks for coronary heart disease (CHD) and depression. Previous studies demonstrated that the reduced CHD and depression risks associated with tall stature were eliminated by financial disadvantage in adult life. HYPOTHESIS: The reduced risk of depression, defined as low mood, associated with taller stature is eliminated by adult financial adversity. This study also attempts to replicate earlier findings, that the reduced risk of CHD associated with taller stature is eliminated by adult financial adversity. METHODS: The Behavioral Risk Factor Surveillance System is an ongoing survey of the adult population of the US conducted by state health departments and the Centers for Disease Control and Prevention, providing a representative sample of 45,210 adults resident in USA in 2004 with data on low mood and CHD. Low mood was defined by self-reported low mood for more than 15 days in the previous month and CHD by a diagnosis of angina or coronary heart disease. Short stature was defined as the lower 20% of sex-standardised heights and economic disadvantage as household income below $15,000 per annum. RESULTS: Tall stature was associated with a statistically significant reduced risk for low mood in the entire population. After stratification by economic disadvantage, taller individuals in the higher income stratum maintained a statistically significant reduced risk of low mood, with an odds ratio (and 95% confidence interval) of 0.90 (0.90, 0.91) after adjustment for potential confounding factors and application of the survey weighting. In contrast, taller stature represented a raised risk for low mood in the lower income stratum, with a statistically significant odds ratio of 1.27 (1.26, 1.28) with weighting. This effect modification was confirmed by interaction testing, producing an odds ratio for interaction of 1.39 (1.37, 1.39; p<0.001). This phenomenon was most profound among white males, with an odds ratio for interaction of 2.20 (2.16, 2.25). Effect modification by economic disadvantage was also observed for the association of height with CHD, producing an odds ratio for interaction of 1.57 (1.56, 1.59; p<0.001). CONCLUSIONS: Although taller stature indicates better heath potential in terms of low mood and CHD, this potential is eliminated by economic disadvantage in later life. Indeed, taller stature is associated with an increased risk among those who experience economic disadvantage. Possible explanations are that childhood adversity reducing height may confer resilience against some forms of adult adversity. Alternatively, as taller stature signals greater childhood advantage, then financial adversity may represent a form of disappointment among this group: the disappointment paradox.     

Sphingolipid distribution changes with age in the human lens

The formation of an internal barrier to the diffusion of small molecules in the lens during middle age is hypothesized to be a key event in the development of age-related nuclear (ARN) cataract. Changes in membrane lipids with age may be responsible. In this study, we investigated the effect of age on the distribution of sphingomyelins, the most abundant lens phospholipids. Human lens sections were initially analyzed by MALDI mass spectrometry imaging. A distinct annular distribution of the dihydrosphingomyelin, DHSM (d18:0/16:0), in the barrier region was observed in 64- and 70-year-old lenses but not in a 23-year-old lens. An increase in the dihydroceramide, DHCer (d18:0/16:0), in the lens nucleus was also observed in the older lenses. These findings were supported by ESI mass spectrometry analysis of lipid extracts from lenses dissected into outer, barrier, and nuclear regions. A subsequent analysis of 18 lenses ages 20–72 years revealed that sphingomyelin levels increased with age in the barrier region until reaching a plateau at approximately 40 years of age. Such changes in lipid composition will have a significant impact on the physical properties of the fiber cell membranes and may be associated with the formation of a barrier.     

Longitudinal analysis of adolescent growth in height,fatness, and fat patterning in rural South African black children

Adolescent growth in height, fatness, and fat patterning was investigated in a sample of 79 rural South African black children studied longitudinally from 6–18 years. Data were analyzed relative to peak height velocity (PHV) to identify the phenomenon of “compensatory” growth in height during adolescence and to describe changes in fatness and fat patterning. Compensatory growth following PHV was clearly observed relative to NHANES data for African-Americans in that Z-scores for height at the start of the adolescent growth spurt were greater than those at the end of the spurt. Statistically significant differences in fatness and centralization between males and females did not occur until about 2 years after PHV was attained. Centralization of fat occurred in both sexes but moreso in males. The lack of centralization in females was due to relatively greater triceps skinfold velocities. The rapid gain in post-PHV fatness in females may represent a physiological adaptation to an energetically sub-optimal environment, buffering the energetic costs of reproduction. © 1994 Wiley-Liss, Inc.     

General body growth in children with cleft palate and related disorders: age differences

Clefts of the lip and palate, separately or in combination, are among the most frequent congenital defects seen today. Their etiology is heterogeneous and may include hormonal factors, which suggest the possibility of growth effects. Whether affected children are smaller than others has not been determined. We recently showed that growth status is associated with type of cleft. We hypothesized genetic alterations in metabolic pathways that alter prenatal growth, producing clefts; some of these alterations also alter postnatal growth. Since the levels of growth-regulating hormones change during ontogeny, we expected age differences in the degree of growth deficit seen. To test this hypothesis, we examine here the cross-sectional means and distributions of standard deviation (z) scores for height and body mass indices (BMIs) for 144 children with the diagnoses unilateral cleft lip and palate (uCLP) and isolated cleft palate (iCP). We find that alteration in growth status is associated with age group as well as sex and diagnosis.     

High-frequency reconstruction of mid-summer temperature from annual height increment of Scots pine at the northern timberline since 1846

Annual height increments of 35 Scots pine (Pinus sylvestris L.) trees from the northern timberline (68°30′N, 27°30′E, 220 m a.s.l., Laanila, North Finland) and monthly climate data from two meteorological stations, Sodankylä (from 1908 to present) and Ivalo (from 1958 to present) were used in climate and growth comparisons. The measured growth series were standardized using 67% splines. A height-increment chronology was built by averaging the indices. This chronology was further divided into high- and low-frequency components using reciprocal filters. Among the temperature variables, mean July temperature of the previous year correlated most significantly with height growth. We compared several simple linear reconstruction models based on the three height-growth chronologies (the unfiltered, high-pass and low-pass filtered chronologies) individually as predictors of the mean July temperature. The high-frequency reconstruction showed superior model performance in calibrations. However, only calibrations using climate data from the nearest Ivalo station were time stable and showed reasonable reconstruction skill. The coefficient of determination (R²) in the final model during calibration period (1958–1998) is 0.67.     

Influence of testicular hormones on the somatostatin-GH system during the growth promoted transition to puberty in sheep

The aim of the present study was to investigate whether the growth promoted transition to puberty in lambs involved changes in the effects of testicular hormones on somatostatin in hypothalamic neurons and GH secretion. The study was performed in infants (9-week-old) testis-intact (TEI) and orchidectomized (ORCHX) at the sixth week of age, and pubertal lambs (16-week-old) TEI and ORCHX at the 12th week of age (n = 20). In TEI lambs, the changes included a pubertal increase in immunoreactive somatostatin in the periventricular nucleus and median eminence with simultaneous neuropeptide depletion in the median eminence, and a decrease in the percentage of the hypophyseal area (PA) occupied by GH-immunoreactive cells (P < 0.05). The mean concentration of GH in the peripheral blood plasma was greater (P < 0.001) in early infancy (5 wk), because of the greater (P < 0.0001) pulse amplitude, and then uniformly low until puberty. The postnatal increase in the body weight (BW) was prominent (P < 0.01) in middle-late infancy (9-12 wk) because of the large daily live-weight gain. After orchidectomy somatostatin was abundant. This effect on nerve terminals in the median eminence was greater (P < 0.01) in infancy and lesser (P < 0.05) in puberty. Conversely, the PA occupied by GH cells was lower in the ORCHX pubertal lambs compared to TEI lambs (P < 0.05). The GH concentration and pulse characteristics were less (P < 0.05) in the infantile and pubertal ORCHX lambs compared to the TEI lambs. However, this effect was weak (P < 0.05) until middle infancy because of no influence on the GH basal concentration, and strong (P < 0.001) after late infancy. The BW did not differ (P > 0.05) between TEI and ORCHX lambs. Findings suggest activation of GH negative autofeedback loop in middle infancy. Testicular factors may play an inhibitory role in regulating somatostatin accumulation and a stimulatory role in GH secretion until puberty. The start of puberty is related to an attenuation in the stimulatory role of gonadal factors in regulating somatostatin depletion in nerve terminals associated with an intensification of the stimulatory role of gonadal factors in regulating GH secretion. From a somatic perspective of growth rate, these mechanisms do not seem to be important. Thus, testicular factors modulate mechanisms within the somatostatin-GH system to integrate somatotropic and gonadotropic functions at the time of growth-promoted sexual maturation in sheep.     

Inferring the economic standard of living and health from cohort height: Evidence from modern populations in developing countries

Average adult height is a physical measure of the biological standard of living of a population. While the biological and economic standards of living of a population are very different concepts, they are linked and may empirically move together. If this is so, then cohort heights can also be used to make inferences about the economic standard of living and health of a population when other data are not available. We investigate how informative this approach is in terms of inferring income, nutrition, and mortality using data on heights from developing countries over the last 50 years for female cohorts born 1951–1992. We find no evidence that the absolute differences in adult height across countries are associated with different economic living standards. Within countries, however, faster increases in adult cohort height over time are associated with more rapid growth of GDP per capita, life expectancy, and nutritional intake. Using our instrumental variable approach, each centimeter gain in height is associated with a 6% increase in income per capita, a reduction in infant mortality of 7 per thousand (or an 1.25 year increase in life expectancy), and an increase in nutrition of 64 calories and 2 grams of protein per person per day relative to the global trend. We find that increases in cohort height can predict increases in income even for countries not used in the estimation of the relationship. This suggests our approach has predictive power out of sample for countries where we lack income and health data.     

Clinical standards for growth in height of Belgian boys and girls,aged 2 to 18 years

The present paper presents the first clinical standard for growth in height of Belgian boys and girls, based on purely longitudinal data. Growth charts are provided with centiles of height for age along with growth curves of the typical early, average and late maturing child in the population. These new standards show the classical features of cross-sectional standards, but above that, they also provide information about the variability in individual growth patterns, as a result of variation in maturation. Average adult height is 176.6 cm (SD=6.3 cm) in boys and 163.3 cm (SD=5.7 cm) in girls. The representativity of these new standards with respect to the actual Belgian population has been by comparison with recent cross-sectional data, collected on a large number of subjects. These standards should be applied in all situations where interest lies in the evaluation of the normality of a child's growth pattern over some length of time and will therefore find their usefulness in clinical follow-up studies of growth.     

Boron deficiency inPinus radiata D. Don and the effect of applied boron on height growth and nutrient uptake

Summary Severe dieback observed inP. radiata D. Don plantations during dry years in Southeastern Australia was found to be due to boron deficiency. Borax applied in spring (August 1982) at rates of 50, 100 and 150 kg ha^–1 resulted in a marked increase in foliar B and an alleviation of B deficiency symptoms. During the dry summer following the application of borax no further dieback was observed and height growth of fertilized trees was significantly improved. Correction of B deficiency enhanced the uptake of P by the trees.