Individual Growth Patterns Research Articles

Effects of corn (Zea mays L.) on the local and overall root development of young rubber tree (Hevea brasiliensis Muel. Arg)

Understanding better the interactions between root systems in associated crops is significant for basic knowledge in plant science and to help designing cropping systems. Current research on inter-specific root interactions concentrates on static descriptions of the horizontal extension of root systems or on the dynamics of provoked root encounters. This study considers detailed observations of the dynamics of inter-specific root interactions, in the vertical plane, at both the whole root system and the individual root levels. Corn and young rubber trees were grown in association in artificial conditions that excluded the possibility of competition for resources, using rhizoboxes, i.e. thin containers with a transparent wall. The paper presents novel approaches, such as the study of root system growth trajectories, to document root system development in terms of overall growth rate, colonization of soil space and individual root growth patterns. It was found that (i) corn roots developed towards rubber roots until a contact was established, (ii) rubber roots expanded faster and more vertically in association with corn, (iii) the expansion rates of both root systems varied concomitantly and (iv) inter-specific root encounters resulted in reduced elongation rates in both species. Implications of these results for corn/rubber inter-cropping are discussed. This work advocates in favour of a better understanding of under-ground facilitative effects between species. If understood enough to be manipulated, such knowledge might become a powerful tool for the design of more sustainable and efficient cropping systems.

A new method for evaluating forest thinning: growth dominance in managed Pinus resinosa stands

Growth dominance is a relatively new, simple, quantitative metric of within-stand individual tree growth patterns, and is defined as positive when larger trees in the stand display proportionally greater growth than smaller trees, and negative when smaller trees display proportionally greater growth than larger trees. We examined long-term silvicultural experiments in red pine ( Pinus resinosa Ait.) to characterize how stand age, thinning treatments (thinned from above, below, or both), and stocking levels (residual basal area) influence stand-level growth dominance through time. In stands thinned from below or from both above and below, growth dominance was not significantly different from zero at any age or stocking level. Growth dominance in stands thinned from above trended from negative at low stocking levels to positive at high stocking levels and was positive in young stands. Growth dominance in unthinned stands was positive and increased with age. These results suggest that growth dominance provides a useful tool for assessing the efficacy of thinning treatments designed to reduce competition between trees and promote high levels of productivity across a population, particularly among crop trees.

Role of Bacteria Isolates in the Spoilage of Fermented African Oil Bean Seed Ugba

Study was carried out to determine the spoilage association of traditionally fermented ugba, product of African oil bean seed. Samples were collected from three markets within Enugu metropolis in Eastern Nigeria. Microbial population of ugba was isolated, characterized and identified. Effect of time on product quality, total viable cell count and individual growth pattern of isolates was evaluated. Microorganisms isolated were Proteus sp., Klebsiella sp., Staphylococcus epidermidis, E. coli, Bacillus licheniformis and Bacillus subtilis. Initial viable cell count increased from 4.6 x 10(8) -6.2 x 10(8), 6.0 x 10(9) -6.9 x 10(9) and 3.9 x 10(8) -5 x 10(8) cfu g(-1) by the 4th day for samples from Mayor, Kenyatta and Garki markets, respectively. Organoleptic changes in texture and colour were seen to be a factor of time of storage. A decline in growth of Proteus sp., E. coli, Klebsiella sp. and S. epidermidis by the 4th day of storage was observed for all samples. Viable cells of B. licheniformis increased from 6.1 x 10(7) -17.7 x 10(7) cfu g(-1), 13.9 x 10(8) -20.0 x 10(8) and 8.7 x 10(7) -15.5 x 10(7) by the 4th day of storage for samples from Mayor, Kenyatta and Garki markets respectively. Growth of B. subtilis increased from 9.2 x 10(7) -19.9 x 10(7), 14.9 x 10(8) -21.2 x 10(8) and 11.5 x 10(7) -17.2 x 10(7) cfu g(-1) for samples from Mayor, Kenyatta and Garki markets respectively. Our results indicate that ugba spoilage is primarily a result of the continued activity of African oil bean seed fermentative organisms B. subtilis and B. licheniformis.

Effects of temperature and growth hormone on individual growth trajectories of wild‐type and transgenic coho salmon Oncorhynchus kisutch

In this study, individual growth patterns of wild-type and growth-enhanced coho salmon Oncorhynchus kisutch at 8, 12 and 16 degrees C water temperature were followed. Despite large differences among individuals in growth rates, there was generally little variation in the shape of the growth curves among O. kisutch individuals of both genotypes and at all temperatures. Typically, individuals that were relatively large initially were also relatively large at the end of the growth period. The limitation in variation was more pronounced in the growth-enhanced O. kisutch than in the wild type, where the relative size of some individuals reared at 12 and 8 degrees C changed by the end of the trial. As a warmer temperature seems to decrease the plasticity of growth trajectories in wild-type fish, it is possible that global warming will influence the ability of wild fish to adapt their growth to changing conditions.

Growth and productivity of black spruce (Picea mariana) belonging to the first cohort in stands within and north of the commercial forest in Quebec, Canada

• The managed area of the North-American boreal forest has been studied extensively. However, because of their inaccessibility, the growth and dynamics of trees at higher latitudes remain unknown, so precluding the possibility of quantifying their productive and economic potential and, if any, their exploitation. • The aim of this paper was to assess individual growth patterns in dominant black spruces (Picea mariana (Mill.) B.S.P.) belonging to the first cohort and to compare growth dynamics within and north of the commercial forest in Quebec, Canada. • Compared with stands located on 49th parallel, stands on 51st parallel showed thinner tree rings and 15% less growth in height, resulting in a 35% reduction in the stem volume attained at the age of 125 years (170 and 110 dm3 for dominant trees in stands within and north of the commercial forest, respectively). At maturity, the annual increment in stem volume in northern stands was 28% lower than that measured in southern stands. • These findings represent important information on tree growth in stands of high-latitude boreal forests and should be taken into account when evaluating the profitability of exploiting the remotest Canadian forests. Confirmation by more extensive and spatially-exhaustive inventories is desirable.

Individual growth pattern and variability in Serranus scriba: a Bayesian analysis

Abstract Alós, J., Palmer, M., Balle, S., Grau, A. M., and Morales-Nin, B. 2010. Individual growth pattern and variability in Serranus scriba: a Bayesian analysis. – ICES Journal of Marine Science, 67: 502–512. Variability in growth patterns at an individual level in Serranus scriba is described using a Bayesian approach for a generalized von Bertalanffy growth model that accommodates one change in growth rate at a specific point during the lifespan. The approach enables individual growth curves to be inferred, even in a species with a relatively short lifespan and no commercial value, i.e. limited sample sizes available, but potentially endangered by recreational fishing. The change in growth rate may be the result of differing allocation of energy between reproductive and somatic activities at different ages. Overall, the approach presented provides adequate input for future implementation of population dynamics models that take into account individual variability, e.g. individual-based models, even for species for which limited data are available.

A distance-independent basal area growth model for oriental spruce (Picea orientalis (l.) Link) growing in mixture with oriental beech (Fagus orientalis Lipsky) in the Artvin region, North-East Turkey

In this study, we developed an individual tree basal area growth model for oriental spruce (Picea orientalis (L.) Link) growing in mixture with oriental beech (Fagus orientalis Lipsky) in the Artvin, Turkey. In our modeling approach, the basal area growth variables were divided into 4 main groups, which included size, competition, site and mixture. The parameters of these variables were biologically consistent with general growth trends of forest growth models and we found them each to be statistically significant at the probability level of 0.05. Our model explained 62.4% of the basal area growth variation of oriental spruce with a standard error of 0.836 cm2. Furthermore, we found that the absolute and relative (%) biases and the root mean square error (RMSE and RMSE%) of the 5 year basal area growth of oriental spruce were 0.00823 cm2, 0.1353%, 0.8234 cm2, 33.39% respectively. We evaluated this model by plotting the biases with respect to considerable regressor variables. These graphical analyses of the model biases showed no meaningful and evident trend of bias values along with these independent variables. Our model provides a clear frame of reference for understanding about the individual tree basal area growth patterns of for oriental spruce growing in mixture with oriental beech. This model further shows that the parameter of the mixture proportion (BP) for oriental beech trees in the mixture model component was positive, indicating that basal area growth of spruce increases as the proportion of beech in the forest mixture goes up if other variables remain constant. This positive effect of admixture may be due to the facilitation process occurring in oriental spruce stands mixed with beech trees. The facilitation pattern of beech trees in mixing spruce stands suggests that poor or degraded forest sites may be improved by mixing beech trees for forest areas in this region. Key words: Oriental spruce, oriental beech, Individual tree basal area growth model, mixed species stands.

Reliability of growth prediction with hand-wrist radiographs

The aim of this study was to investigate the validity of hand-wrist radiographic analysis in estimating the amount of remaining craniofacial growth. The material compromised cephalograms of 22 males and 27 females with a Class I malocclusion. The median age of the females at the beginning (T1) was 11 years 10 months and of the males 12 years 6 months and at the end (T2) of treatment 14 years 7 months and 15 years 3 months, respectively. Statural height was measured and a lateral cephalogram was obtained for every patient at T1 and T2. A hand-wrist radiograph was taken only at T1. The cephalograms were scanned and analyzed. Relative dimensional growth changes in statural height as well as of the length of the cranial base (N-S), the maxilla (Ptm-A), and the dimensions of the mandible (Co-Gn, Go-Gn, and Co-Gn) from T1 to T2 were determined and statistically compared (Pearson's correlation coefficients) with the growth prediction assessed with the help of hand-wrist radiographs according to Greulich and Pyle. The results showed a highly significant correlation between statural growth increases and growth prediction assessed from the hand-wrist radiographs (females: r = 0.68; males: r = 0.7). Concerning craniofacial structures, the increase in mandibular corpus showed the highest correlation with growth prediction (females: r = 0.21; males: r = 0.52), but this association would not allow a reliable growth prediction. There was no significant correlation between growth increases of the cranial base, the maxilla, the ramus, and the effective length of the mandible and growth prediction assessed with the help of hand-wrist radiographs. As each patient has an individual growth pattern and different craniofacial structures show individual growth potential, it is questionable if quantitative craniofacial growth prediction with the help of hand-wrist radiographs is reliable. However, in an individual case for the assessment of the timing of the growth process, a hand-wrist radiograph can contribute to treatment planning.

Potential of stem/progenitor cell cultures within polyester fleeces to regenerate renal tubules

The cell biological mechanism controlling the regeneration of renal tubules in renal failure after application of stem/progenitor cells is subject of actual research. Unsolved issues are the integration of stem/progenitor cells in a diseased organ environment, the differentiation into epithelial tissue and the formation of tubules in a spatial environment. Following this therapeutic strategy new biomaterials have to be found promoting spatial development of tubules. To obtain new information about the growth of tubules renal stem/progenitor cells from neonatal rabbit kidney were isolated and mounted in a tissue carrier between a selection of commercially available polyester fleeces. This procedure replaces coating by extracellular matrix proteins and creates an artificial interstitium supporting development of tubules. Perfusion culture was performed with chemically defined IMDM containing aldosterone as tubulogenic factor. Polyester fleeces were investigated by scanning electron microscopy. The spatial development of tubules was registered on whole-mount specimens and on cryosections labeled with SBA and antibodies indicating tubule differentiation. It is found that some polyester fleeces promote the spatial development of tubules between the fibers, whereat each of them produces its individual growth pattern.

Individual differences in trajectories of arithmetical development in typically achieving 5- to 7-year-olds

The arithmetical performance of typically achieving 5- to 7-year-olds ( N = 29) was measured at four 6-month intervals. The same seven tasks were used at each time point: exact calculation, story problems, approximate arithmetic, place value, calculation principles, forced retrieval, and written problems. Although group analysis showed mostly linear growth over the 18-month period, analysis of individual differences revealed a much more complex picture. Some children exhibited marked variation in performance across the seven tasks, including evidence of difficulty in some cases. Individual growth patterns also showed differences in developmental trajectories between children on each task and within children across tasks. The findings support the idea of the componential nature of arithmetical ability and underscore the need for further longitudinal research on typically achieving children and of careful consideration of individual differences.

Craniofacial Growth Patterns in Patients with Congenitally Missing Permanent Teeth*

Aim of this study was to investigate any correlations between the congenital absence of certain permanent teeth and individual craniofacial growth patterns. The lateral cephalograms of n = 101 patients (65 female und 36 male) with various congenitally missing teeth were analyzed according to Hasund [11] prior to orthodontic treatment. Cephalometric data to determine the craniofacial growth pattern comprised GntgoAr, NSBa, ML-NSL, NL-NSL, MLNL angles and the index between upper and lower facial heights. Correlations between the type of missing teeth and growth pattern were examined. Group distribution was A = all patients with missing teeth (n = 101), P = missing second premolars (n = 49), S = missing upper lateral incisors (n = 30), X = various missing teeth (n = 22). We included a control group for each of these groups using data from Riolo et al.'s [22] growth study. Group A revealed an even distribution with n = 32 patients (31.7%) having a vertical growth pattern, n = 37 patients (36.6%) a neutral growth pattern, and n = 32 patients (31.7%) a horizontal growth pattern. The majority of patients (n = 20, 40.8%) in group P exhibited a horizontal growth pattern, whereas there were no significant correlations between the kind of congenitally missing teeth and growth patterns in groups S and X. Comparison of the mean values of groups P, S and X, revealed no significant differences. When comparing the control group to groups A, P and S, we noted significantly or highly significantly smaller gonial and basal plane angles. No significant differences were apparent concerning group X. This examination demonstrates no statistically-relevant correlation between craniofacial growth pattern and the congenital absence of certain permanent teeth, although horizontal growth is more frequent (but not significant) in patients with congenitally missing second premolars.

Age determination and growth by skeletochronology of Rana holtzi, an endemic frog from Turkey

We applied skeletochronology on phalanges to assess the individual age and growth patterns of a breeding population portion of Rana holtzi, an endemic frog from Turkey. Snout–vent length (SVL) ranged from 46.4 to 66.8 mm for males and 39.2 to 66 mm for females. Ages ranged from 4 to 6 years for males, and from 4 to 7 for females. Neither SVL nor age differed between the sexes. Both males and females showed high variability of growth patterns during ontogeny. The high frequency of double LAG (lines of arrested growth), observed mainly in the males, suggests that the frogs of our sample experienced frequent but not periodic growth arrests. We stress the practical value of skeletochronology for population survey on this interesting endemism which is at great risk of decline due to human causes.

T10-P-02 Mind, body, voice-a project for health

Objective the aim of this work is to show the educational projects and the activities realized in Volterra at the Unita Funzionale Salute Mentale Adulti (UFSMA) in behalf of social integration, finding and expression of affection and sexuality in disabled people. The project Fatti di Sport started in 2003 as a collaboration between Polisportiva Saline and its members and athletes, and the Mental Health service of USL5 of Pisa. Its aim was to promote patterns of individual growth and social integration, through sport. The project embraces many activities such as regional, national and international volleyball and five-a-side football tournaments, sailing manifestation and trekking. All the participants, without distinction, are members of the Polisportiva Saline. In 2002, as a consequence of the fulfilment of a music therapy project, the chorus Apparenti stonature, was established. Composed by operators and volunteers, the project aims to offer, through singing and sharing, a “second-reading” of daily experience, that involves mind, affections and senses. The training of professional figures working in the field of disability is fundamental: in June 2007 the Handicap and sexuality day of national study took place, paving the way to the training courses that will be realized from January 2008. Results Increase number participating in the project. Conclusions improving the quality of life and life skills.

Growth and development rates in a riparian spider are altered by asynchrony between the timing and amount of a resource subsidy

Rapid growth in response to increased prey abundance may be induced by environmental variability associated with resource subsidies. Spiders living in riparian areas are subject to frequent, episodic bursts of aquatic prey (subsidies). These periods of high resource abundance may occur at different points in recipient consumers' development through variation in emergence patterns of prey between years or across a landscape. We examine how variable timing of subsidy abundance intersects with life history scheduling to produce different growth and development outcomes for individuals within a population. Through a series of controlled feeding experiments, we tested the hypotheses that the spider Tetragnatha versicolor: (1) exhibits compensatory growth in response to subsidy variability, (2) that rapid increases in mass may result in a greater risk of mortality, and (3) that the timing of subsidy resources relative to the development schedule of this spider may produce different outcomes for individual growth patterns and adult condition. Spiders fed at very high rates grew fastest but also showed evidence of increased mortality risk during moulting. T. versicolor is capable of exhibiting strong growth compensation-individuals suffering initial growth restriction were able to catch up completely with animals on a constant diet utilising the same amount of food. Spiders that received an early pulse of resources (simulating an early arrival of an aquatic insect subsidy to riparian forests) did worse on all measures of development and fitness than spiders that received either a constant supply of food or a late pulse of resources. Importantly, receiving large amounts of food early in life appears to actually confer relative disadvantages in terms of later performance compared with receiving subsidies later in development. Subsidies may provide greater benefits to individuals or age cohorts encountering this resource abundance closer to the onset of reproductive efforts than subsidies arriving early in development.

Patterns of individual growth of gray garden slug Deroceras reticulatum

Individual growth of gray garden slug Deroceras reticulatum was studied under laboratory conditions in the period from collection to death. The studied population demonstrated different patterns of growth. Three groups of slugs were recognized: (1) slugs that reached the maximum weight after 4 months of raring, after which their weight rapidly decreased (the life span in culture was 6-7 months); (2) slugs that have not reached the maximum weight until death (the life span was 6-7 months); (3) slugs that reached the maximum weight after 7-8 months, after which their weight oscillated with a trend to decrease (the life span was about 10 months). The obtained data were approximated by the equation of finite growth.

Is reproductive failure responsible for reduced recruitment of intertidalMytilus edulis L. in the western Dutch Wadden Sea?

The musselMytilus edulis is an abundant bivalve in the Dutch Wadden Sea, both in intertidal areas as well as in subtidal culture plots. From mid 1980’s to late 1990’s, strong declines in mussel intertidal populations have been observed, both in terms of occupied area and in biomass. Despite the efforts since 1999 to preserve intertidal mussel beds, abundance and biomass of mussels in the Dutch Wadden Sea are at present still much lower than in the 1970’1s. In the present paper, we tested whether reproductive failure could have been the cause for the low recruitment ofM. edulis in the western Dutch Wadden Sea. Water temperature is an important factor influencing growth and reproduction in bivalves. The observed increase in mean temperature in the Dutch Wadden Sea during the last decades suggests that an effect of temperature on the population dynamics of mussels might be expected. Nevertheless, no significant relationship was found between body condition and mean winter temperature. Therefore, a decrease in body condition and, consequently, in reproductive output, due to increasing temperature, will not have been a cause for the observed low recruitment in recent years. The seasonal patterns of individual growth supported this view: most adults developed gonads during the spawning season suggesting that reproductive (gametogenic) failure was not a cause for the low recruitment. Nevertheless, reproductive investment by the mussel population studied was not optimal since complete spawning hardly occurred. In addition, the high gonadosomatic ratio at the end of the summer did not result in heavy spawning, suggesting resorption of gonadal tissue due to unfavourable environmental conditions (too high temperature and/or food limitation during summer). Reduced recruitment could be due to poor spawning but other factors that exert their influence after spawning (predation on larvae or postlarvae, lack of settlement substrate) or on the adult population (decrease in number of spawners) are also likely to be involved in the observed low recruitment during the last years.

Sexual size dimorphism, growth, and maturity of the fluvial eight-barbel loach in the Kako River, Japan

The maturation and growth pattern of the fluvial eight-barbel loach Lefua sp. (Japanese name: nagare-hotoke-dojo), an endangered species, was investigated using an individual identification-recapture method from 1995 to 1998 in an upper reach of a headwater tributary of the Kako River, Hyogo Prefecture, Japan. Based on observations of the gonads through the abdominal skin, the loach was estimated to breed mostly from May to July. All the males matured by age 1+, and all the females matured by age 2+. Gamete release in all individuals of both males and females was predicted from recaptured loaches during each breeding season. The standard length of mature females was significantly larger than that of males, showing sexual size dimorphism (SSD). The maximum sizes recorded were 75.4 mm SL for females and 61.2 mm SL for males. Both males and females of immature specimens grew mainly from May to November, including the breeding season, with no significant differences in growth rates between them. After sexual maturity, both males and females grew mainly from July to October (or November), after the breeding season, and the females exhibited higher growth rates than males. Therefore, SSD of the species seems to be attributable to the different growth rates after maturity. The longevity of the loach was estimated to exceed ten years based on individual growth patterns of various sizes during the survey period. It is likely that the loach has an iteroparous life history, breeding every year, and moderate growth rates after maturity.

Growth chart curves do not describe individual growth biology

Growth reference tables present statistical distributions of size for age of individuals within a sample or population. As summaries of phenotypic variability at the group level, they document that individuals grow by different rates during similar time frames. The data are commonly fitted by mathematical functions to produce the convex curves of percentile distributions useful for infant and childhood growth monitoring. In this form, the growth chart appears to be a frame of reference for judging how well an individual infant/child is progressing through time by comparison with peers across ages. This has led to the assumption that individuals should track in these channels during growth. The interpolated lines between the statistical distributions of size for age at the level of the population do not, however, represent how individuals grow. Growing is an individual process characterized by nonlinear episodic saltatory increments that result in shifting size relationships among similarly aged peers over short time intervals. Data from a prospective, longitudinal study of infants illustrate the poor performance of growth chart curves as representations of individual growth. Clarification of the paradigms supporting perceptions of normal growth patterns is useful both practically and theoretically: growth chart patterns have important clinical sequelae when this informs feeding recommendations. Further characterization of individual growth patterns will contribute to increased understanding of both individual growth biology and the nature of adaptability.

Epidemiology, genes and the environment: lessons learned from the Helsinki Birth Cohort Study

Nonoptimal growth during fetal life and infancy is associated with an increased risk of coronary heart disease and type 2 diabetes later in life. This early pattern of growth is associated with an increased disease risk especially when followed by a relative gain in body size later in childhood. Genetic factors are closely involved in growth and disease pathogenesis and gene-early life environmental interactions will be described affecting adult health outcomes. This overview will primarily focus upon findings from the Helsinki Birth Cohort Study consisting of 15846 subjects born 1924-1944 on whom growth data and information on adult health are available.

Population dynamics of naturalised Manila clams Ruditapes philippinarum in British coastal waters

The Manila clam Ruditapes philippinarum was introduced to Poole Harbour (lat 50°N) on the south coast of England in 1988 as a novel species for aquaculture. Contrary to expectations, this species naturalised. We report on individual growth patterns, recruitment, mortality and production within this population. On the intertidal mudflats the abundance of clams (>5 mm in length) varied seasonally between 18 and 56 individuals m−2. There appear to be two recruitment events per year and there were 6 year classes in the population. A mid-summer decline in abundance was partly due to increased mortality but probably also a result of down-shore migration in response to high water temperatures and the development of anoxic conditions. A winter fishery removes c 75% of clams of fishable size (maximum shell length ≥40 mm) and c 20% of the annual production. The fishery depresses the maximum age and size attained by the clams but appears to be sustainable. Clam mortality due to factors other than fishing is highest in late-winter to early spring. The growth of the clams is intermediate in comparison with many published studies but remarkably good given their intertidal position. As on the coasts of the Adriatic Sea, where the clam is also non-native, the Manila clam has thrived in a shallow, eutrophic, lagoon-like system on the English coast. While the Poole Harbour population is currently Europe’s most northerly reported self-sustaining, naturalised population, given forecasts of increasing air and sea temperatures it might be expected that this species will eventually spread to more sites around the coasts of Northern Europe with associated economic and ecological consequences.