Quantitative Growth Analysis Research Articles

Arabidopsis floral buds are locked through stress-induced sepal tip curving.

In most plant species, sepals-the outermost floral organs-provide a protective shield for reproductive organs. How the floral bud becomes sealed is unknown. In Arabidopsis, we identified a small region at the sepal tip that is markedly curved inward early on and remains curved even after anthesis. Through modelling and quantitative growth analysis, we find that this hook emerges from growth arrest at the tip at a stage when cortical microtubules align with growth-derived tensile stress. Depolymerizing microtubules specifically at young sepal tips hindered hook formation and resulted in open floral buds. Mutants with defective growth pattern at the tip failed to curve inwards, whereas mutants with enhanced alignment of cortical microtubules at the tip exhibited a stronger hook. We propose that floral buds are locked due to a stress-derived growth arrest event curving the sepal tip and forming a rigid hook early on during flower development.

Efficacy of combinational therapy using blue light and benzoyl peroxide in reducing Cutibacterium acnes bioburden at the deltopectoral interval: a randomized controlled trial.

The purpose of this study was to compare the efficacy of blue light therapy (BLT) and 5% topical benzoyl peroxide (BPO) gel in combination with standard chlorhexidine (CHX) preparation in eradicating Cutibacterium acnes at the deltopectoral interval measured by positive, quantitative culture findings. Adult male volunteers were randomized to 1 of 3 treatment groups: BPO, BLT, and BPO followed by BLT. Contralateral shoulders served as matched controls. Volunteers randomized to BPO applied the gel for a total of 5 treatments. In the BLT group, a single 23-minute treatment was administered at an estimated irradiance of 40 mW/cm2 (radiant exposure, 55.2 J/cm2). In the BPO-BLT group, volunteers received both treatments as described earlier. After treatment with either BPO, BLT, or both, a single swab culture was taken from the treatment shoulder. Next, control and treatment shoulders were prepared with CHX, and cultures were taken from each shoulder. Cultures were sent for anaerobic quantitative growth analysis with both polymerase chain reaction and Sanger sequencing confirmation of presumptive C acnes colonies. This study enrolled 60 male volunteers, 20 per group, with no loss to follow-up. After treatment but prior to CHX administration, all culture samples in the BPO group and BLT group grew C acnes. Prior to CHX, 16 samples (80%) in the BPO-BLT group grew C acnes. On quantitative analysis, the BPO group and BPO-BLT group had significantly less growth of C acnes compared with the BLT group after treatment but prior to CHX (P < .05 for each). Following CHX administration, the BPO and BPO-BLT groups had significantly fewer positive culture findings (odds ratios of 0.03 and 0.29, respectively) and less quantity of growth compared with their control arms (P < .05). This was not seen in the BLT group. For quantitative between-group analysis, no significant synergistic effects were seen with BPO-BLT compared with BPO alone (P = .688). There was no difference in side effects between groups. The combination of topical BPO and CHX was effective at eliminating C acnes in most cases. BLT alone did not demonstrate effective antimicrobial properties against C acnes at the radiant exposure administered in this study. Combining BPO and BLT did not lead to significant synergistic antimicrobial effects. Both BPO and BLT are safe with few, transient side effects reported. More work is needed to determine whether BLT at higher radiant exposures or serial treatment results in bactericidal effects against C acnes invivo.

GROWTH DYNAMICS OF SESAME CULTIVARS

ABSTRACT Sesame is a plant with high morphological and physiological complexity, with great variability in growth habit. Quantitative growth analysis is an accessible and accurate tool for evaluating plant development and the contribution of different physiological processes to plant performance. In view of this, the purpose of this study was to evaluate the growth of sesame cultivars in two cropping seasons in the conditions of Mossoró-RN. Two experiments were conducted in Horta Didactics of UFERSA. The experimental delineation in each time was a randomized complete block design with four replications. The treatments were arranged in split plots where each experimental plot contained different sesame cultivars, CNPA G2, CNPA G3 and CNPA G4, and the subplots represented seven collection times, 21, 35, 49, 63, 77, 91 and 105 days after sowing (DAS). The growth of the sesame cultivars was slow at the beginning of the crop cycle, intensifying at the beginning of flowering (after 35 DAS). Among the physiological indexes studied, CNPA G4 cultivar was more efficient in relation to growth and varied depending on the cropping season.

Quantitative growth analysis of pulp necrotic tooth (post‐op) using modified region growing active contour model

In the field of dentistry, prospective clinical study reports affirm the need for approximate growth analysis of endodontic tooth post treatment. There is no difference in the frequency, appearance or extent of root resorption in the teeth. It is necessary to elucidate the role of endodontic treatment in the root resorption. Differences between the two samples (radiographs), which are taken with specified period of intervals, in terms of the frequency of growth changes in treated teeth is needed to observe accurately. This study mainly aims at this requirement by utilising slightly modified region-based growing active contour model for quantitative growth analysis of tooth. Recall radiographs of endodontic regeneration involving immature permanent teeth with pulp necrosis have been considered as input in this research. Image enhancing techniques such as dilation and erosion of mathematical morphology are then performed sequentially to emphasise the outlying pixels. Finally, the criterions which include the root length, apical diameter and the dentinal wall thickness are calibrated and given in experimental results. The visual sample results and along with its measurements proved the efficiency of the proposed algorithm.

Post calibration of the two-dimensional electron cyclotron emission imaging instrument with electron temperature characteristics of the magnetohydrodynamic instabilities.

The electron cyclotron emission imaging (ECEI) instrument is widely used to study the local electron temperature (Te) fluctuations by measuring the ECE intensity IECE ∝ Te in tokamak plasmas. The ECEI measurement is often processed in a normalized fluctuation quantity against the time averaged value due to complication in absolute calibration. In this paper, the ECEI channels are relatively calibrated using the flat Te assumption of the sawtooth crash or the tearing mode island and a proper extrapolation. The 2-D relatively calibrated electron temperature (Te,rel) images are reconstructed and the displacement amplitude of the magnetohydrodynamic modes can be measured for the accurate quantitative growth analysis.

Growth, Quantitative Growth Analysis, and Applications of Graphene on γ-Al2O3 catalysts.

The possibilities offered by catalytic γ-Al2O3 substrates are explored, and the mechanism governing graphene formation thereon is elucidated using both numerical simulations and experiments. The growth scheme offers metal-free synthesis at low temperature, grain-size customization, large-area uniformity of electrical properties, single-step preparation of graphene/dielectric structures, and readily detachable graphene. We quantify based on thermodynamic principles the activation energies associated with graphene nucleation/growth on γ-Al2O3, verifying the low physical and chemical barriers. Importantly, we derive a universal equation governing the adsorption-based synthesis of graphene over a wide range of temperatures in both catalytic and spontaneous growth regimes. Experimental results support the equation, highlighting the catalytic function of γ-Al2O3 at low temperatures. The synthesized graphene is manually incorporated as a ‘graphene sticker’ into an ultrafast mode-locked laser.

Broad metabolic sensitivity profiling of a prototrophic yeast deletion collection

BackgroundGenome-wide sensitivity screens in yeast have been immensely popular following the construction of a collection of deletion mutants of non-essential genes. However, the auxotrophic markers in this collection preclude experiments on minimal growth medium, one of the most informative metabolic environments. Here we present quantitative growth analysis for mutants in all 4,772 non-essential genes from our prototrophic deletion collection across a large set of metabolic conditions.ResultsThe complete collection was grown in environments consisting of one of four possible carbon sources paired with one of seven nitrogen sources, for a total of 28 different well-defined metabolic environments. The relative contributions to mutants' fitness of each carbon and nitrogen source were determined using multivariate statistical methods. The mutant profiling recovered known and novel genes specific to the processing of nutrients and accurately predicted functional relationships, especially for metabolic functions. A benchmark of genome-scale metabolic network modeling is also given to demonstrate the level of agreement between current in silico predictions and hitherto unavailable experimental data.ConclusionsThese data address a fundamental deficiency in our understanding of the model eukaryote Saccharomyces cerevisiae and its response to the most basic of environments. While choice of carbon source has the greatest impact on cell growth, specific effects due to nitrogen source and interactions between the nutrients are frequent. We demonstrate utility in characterizing genes of unknown function and illustrate how these data can be integrated with other whole-genome screens to interpret similarities between seemingly diverse perturbation types.

Inducible Repression of Multiple Expansin Genes Leads to Growth Suppression during Leaf Development

Expansins are cell wall proteins implicated in the control of plant growth via loosening of the extracellular matrix. They are encoded by a large gene family, and data linked to loss of single gene function to support a role of expansins in leaf growth remain limited. Here, we provide a quantitative growth analysis of transgenics containing an inducible artificial microRNA construct designed to down-regulate the expression of a number of expansin genes that an expression analysis indicated are expressed during the development of Arabidopsis (Arabidopsis thaliana) leaf 6. The results support the hypothesis that expansins are required for leaf growth and show that decreased expansin gene expression leads to a more marked repression of growth during the later stage of leaf development. In addition, a histological analysis of leaves in which expansin gene expression was suppressed indicates that, despite smaller leaves, mean cell size was increased. These data provide functional evidence for a role of expansins in leaf growth, indicate the importance of tissue/organ developmental context for the outcome of altered expansin gene expression, and highlight the separation of the outcome of expansin gene expression at the cellular and organ levels.

Spatio‐temporal quantification of differential growth processes in root growth zones based on a novel combination of image sequence processing and refined concepts describing curvature production

Differential growth processes in root and shoot growth zones are governed by the transport kinetics of auxin and other plant hormones. While gene expression and protein localization of hormone transport facilitators are currently being unraveled using state-of-the-art techniques of live cell imaging, the quantitative analysis of growth reactions is lagging behind because of a lack of suitable methods. A noninvasive technique, based on digital image sequence processing, for visualizing and quantifying highly resolved spatio-temporal root growth processes was applied in the model plant Arabidopsis thaliana and was adapted to provide precise information on differential curvature production activity within the root growth zone. Comparison of root gravitropic curvature kinetics in wild-type and mutant plants altered in a facilitator for auxin translocation allowed the determination of differences in the location and in the temporal response of curvature along the growth zone between the investigated plant lines. The findings of the quantitative growth analysis performed here confirm the proposed action of the investigated transport facilitator. The procedure developed here for the investigation of differential growth processes is a valuable tool for characterizing the phenomenology of a wide range of shoot and root growth movements and hence facilitates elucidation of their molecular characterization.

Towards plant systems biology – novel mathematical approaches to enable quantitative analysis of growth processes

Towards plant systems biology – novel mathematical approaches to enable quantitative analysis of growth processes

Productivity of young shaded oaks ( Quercus robur L.) as corresponding to shoot morphology and leaf anatomy

During a 2 year field experiment, pedunculate oaks ( Quercus robur L.) were grown from acorns under different and changing light intensities. The four light intensities studied were full daylight and 50, 25 and 10% of full light intensity. Half of the oaks, subjected to experimental full shade (10% relative light intensity) in the first year of growth were then grown under 25% relative light intensity in the second year. Results of quantitative growth analysis (Evans, 1972) reveal a high shoot productivity of the 2-year-old oaks down to 25% relative light intensity. Oaks subjected to the permanent full shade treatment survived but suffered from heavy growth depressions. Content of the storage carbohydrate ‘starch’ is extraordinarily high in 1-year-old oaks. Storage capacity of the root (rates of starch partitioning associated with root dry mass) was at its minimum in oaks grown under 10% relative light intensity. Selected parameters of leaf transection showed distinct transition from ‘sun-leaves’ to ‘shade-leaves’ in oaks subjected to 25% relative light intensity. The transposed oaks (first year 10% relative light intensity, second year 25% relative light intensity) ‘re-gained’ a considerably high shoot productivity. The selected anatomical parameters of the transposed oaks were determined by the light conditions prevailing in the previous year, with the exception of striking increases of inner and outer leaf surfaces.

A Comparison of the Growth of the C4GrassSpartina anglicawith the C3Grass Lolium perenne at Different Temperatures

Dunn, R., Thomas, S. M., Keys, A. J. and Long, S. P. 1987. A comparison of the growth of the C4 grass Spartina anglica with the C3 grass Lolium perenne at different temperatures.—J. exp. Bot. 38:433-441. S. anglica is one of the few C4 species which occurs naturally in cool temperate zones. It is known to attain photosynthetic rates which equal or exceed those of C3 grasses over the temperature range typical of the spring and summer in cool temperate climates. This study examines whether S. anglica can also attain comparable growth rates at these temperatures. Seedlings of S. anglica and L. perenne cv. S23 were grown in controlled environments at 10,15,20 and 25 °C. Quantitative growth analysis was conducted by taking frequent harvests to determine the progressions of leaf area and plant weight of individual plants with time. Quadratic regressions were found to describe these progressions well. Instantaneous derived growth parameters were calculated from the fitted regressions. Both absolute and relative growth rates of S. anglica were significantly lower than for L. perenne, this being largely attributable to a lower ratio of leaf area production per unit of plant dry weight. Although the amount of dry matter invested into leaves was similar, the leaf area per unit of leaf dry weight was lower in S. anglica. In comparison to L. perenne, the rate of dry matter accumulation per unit of leaf area ( VLR) was higher in S. anglica at 25 °C and initially equal at 10 °C. Prolonged exposure to 10 °C steadily reduced ULR in S. anglica which approached zero at 80 d. Although growth in S. anglica is reduced more by low temperature than it is in L. perenne, by comparison to other C4 species the assimilatory

Effect of Contrasted Planes of Nutrition on the Carcass Composition of the East African Dwarf Goat

THE classic studies of Hammond1 on the mutton qualities of sheep initiated a great volume of work on the problems associated with the production of high-quality meat. The chief technique used in this field has been that of ‘quantitative growth analysis’. By this means, changes due to different genetic factors between breeds within a species1,2 and changes due to different patterns of growth have been studied, and the results interpreted in terms of the theories of allometric and heterogenic growth and centripetal development first postulated by Brody4 and Huxley5.

Growth analysis of the domestic fowl II. Effect of plane of nutrition on carcass composition

1. Two sample cockerels from each plane of nutrition treatment were killed and dissected at 0, 4, 10, 15 and 24 weeks of age. Details of the dissection technique are given.2. All organs and tissues were weighed both wet and oven-dried. The total dry-matter content of the birds increased from 21% at hatching to 32% at 24 weeks.3. The chief age changes in the proportions of the major joints of the bird consist of a marked increase in relative mass of wing, and a lesser increase in the leg joints. The early maturing head and neck joints decrease in relative mass by approximately onehalf. There are no treatment differences in the gross proportions of the birds calculated on the basis of weights of the major joints.4. The advantages and disadvantages of the various methods of presenting quantitative growth analysis data are discussed. Reasons are given for employing several different methods in this work.5. The amount of fat in the carcasses analysed varies considerably between individual birds. There are no consistent age or treatment effects on the fat contents of the cockerels. The interpretation of McMeekan's dissection analysis data is discussed, and reasons are advanced for conducting future experiments of similar nature on the basis of a fatfree carcass. It is argued that adipose deposits should not be considered in the same category as body organs and tissues.