Growth Duration Research Articles

Formation mechanism of bi-modal cell structure polystyrene foams by synergistic effect of CO2-philic additive and co-blowing agent

A new method was developed for the formation of bi-modal cell structure polystyrene (PS) foams by synergistic effect of CO2-philic additive (PDMS) and co-blowing agent (alcohol). The results showed that PDMS and alcohol synergistically increased the solubility and diffusion coefficient of CO2 into PS and reduced the desorption rate from PS. The blowing agent formed a high-concentration area in the PDMS (6000 g/mol) phase to promote bubble nucleation and growth in advance. The moderate size and number of cells were pre-formed, slowing the CO2 desorption and increasing the duration of bubble growth, so that bi-modal cell structure PS foams with high cell density and volume expansion ratio were obtained. Moreover, the solution and diffusion behavior of CO2 and the cell morphology could be easily tuned by changing the composition of complex additives, which might be a promising strategy for preparing bi-modal cell structure in different foaming processes.

Linear growth of lateral shoots of plants belonging to the genus <i>Crataegus</i> L. and the influence of the temperature factor during introduction in the Arctic zone of the Russian Federation (Kola Peninsula)

This study is devoted to assessing the patterns of seasonal growth of lateral shoots of introduced Crataegus L. species beyond the Arctic Circle (using the example of the Kola Peninsula). The paper presents the timing of the onset and end of the linear growth of shoots, the duration of the shoots growth, the influence of the thermal regime on the duration and intensity of the growth of shoots belonging to some species of hawthorn. The beginning of linear growth of shoots in introduced hawthorn species on average occurs on June 1. The sequential series of hawthorn species according to the timing of the onset of linear growth of shoots from early to late is as follows: C. sanguinea, C. flabellata, C. maximowiczii, C. laevigata, C. dahurica, C. russanovii. The average duration of shoot growth for 20182020 was 38 days. The shortest increase was observed in 2019 for C. russanovii, the maximum increase was recorded for C. maximowiczii plants in 2018. The differences in the annual growth of shoots of the studied hawthorn species are due to the intensity, not the duration of growth. C. sanguinea, C. maximowiczii belong to the group of species with the highest requirements for heat accumulated by the end of the shoot growth period, C. dahurica plants were characterized by the least accumulation of positive temperatures.

Towards a Standardized Procedure for the Production of Infective Spores to Study the Pathogenesis of Dermatophytosis.

Dermatophytoses are superficial infections of human and animal keratinized tissues caused by filamentous fungi named dermatophytes. Because of a high and increasing incidence, as well as the emergence of antifungal resistance, a better understanding of mechanisms involved in adhesion and invasion by dermatophytes is required for the further development of new therapeutic strategies. In the last years, several in vitro and in vivo models have emerged to study dermatophytosis pathogenesis. However, the procedures used for the growth of fungi are quite different, leading to a highly variable composition of inoculum for these models (microconidia, arthroconidia, hyphae), thus rendering difficult the global interpretation of observations. We hereby optimized growth conditions, including medium, temperature, atmosphere, and duration of culture, to improve the sporulation and viability and to favour the production of arthroconidia of several dermatophyte species, including Trichophyton rubrum and Trichophyton benhamiae. The resulting suspensions were then used as inoculum to infect reconstructed human epidermis in order to validate their ability to adhere to and to invade host tissues. By this way, this paper provides recommendations for dermatophytes culture and paves the way towards a standardized procedure for the production of infective spores usable in in vitro and in vivo experimental models.

Growth of Neanderthal infants from Krapina (120-130 ka), Croatia.

Modern humans have a slow and extended period of childhood growth, but to what extent this ontogenetic pathway was present in Neanderthals is debated. Dental development, linked to the duration of somatic growth across modern primates, is the main source for information about growth and development in a variety of fossil primates, including humans. Studies of Neanderthal permanent teeth report a pace of development either similar to recent humans or relatively accelerated. Neanderthal milk teeth, which form and emerge before permanent teeth, provide an opportunity to determine which pattern was present at birth. Here we present a comparative study of the prenatal and early postnatal growth of five milk teeth from three Neanderthals (120 000-130 000 years ago) using virtual histology. Results reveal regions of their milk teeth formed quickly before birth and over a relatively short period of time after birth. Tooth emergence commenced towards the earliest end of the eruption schedules displayed by extant human children. Advanced dental development is consistent with expectations for Neanderthal infant feeding.

Biomechanical properties of the growing and decaying roots of Cynodon dactylon

Root growth and decay may affect root reinforcement to soil erosion and stability. We measured the effects of growth and decay on the tensile strength of Cynodon dactylon roots considering different causes of mortality common to agricultural land conversion (i.e. burning and herbicide application). We applied three treatments to C. dactylon grass: (i) growth duration (60, 120 and 180 days), (ii) decay duration after burning (30, 60, 120, 180 and 360 days) and (iii) decay duration after herbicide application (15, 30 and 60 days). The diameter, tensile strength and cellulose and lignin contents of root samples (n = 303) in different treatments were measured. Tensile strength–diameter relations followed a negative power law regardless of treatment (R2 > 0.6). The increase in median tensile strength values due to grass growth was consistent with the increase in cellulose and lignin contents. Root decay by herbicide application caused significantly greater and faster reduction in tensile strength than burning treatment because of the faster reduction of cellulose and lignin contents. Root decay due to different causes of plant mortality can increase susceptibility to erosion and slope instability during the conversion of agricultural land. Measures on slope safety and erosion are vital when using herbicides for weed clearance in farmlands due to the faster deterioration of root chemical composition and root tensile strength (compared with burning).

Modeling of zircon nucleation and growth rates using crystal size distributions in a cooling magmatic intrusion

With a rapid increase in the use of zircons for geochronology and in situ isotopic and chemical analyses it is important to quantify growth rates and nucleation rates of zircons in natural magmatic systems. Here we present a mathematical model of the nucleation and growth of a population of zircon crystals in a cooling magmatic intrusion and apply nucleation laws to derive zircon crystal size distributions (CSD) and particle number density (n per cm3 of melt) from first principles. The model is based on a numerical solution of the one-dimensional diffusion equation that accounts for the nucleation and growth of individual crystals and the dependence of the equilibrium concentration of Zr on temperature. As experimental studies of zircon nucleation at natural concentration levels of Zr are nearly impossible, we rely on measured CSDs of age-invariant (within error of the method <±5ky) zircon populations in rapidly quenched eruptive products of known crystallization duration to calibrate our model. The CSDs of zircon crystals are calculated at different rates of cooling of the magma chamber and are compared to measurements. The combination of the zircon growth software with measurements of zircon CSDs and particle number density permits direct estimation of the zircon nucleation rates and their evolution with time in cooling magmatic systems. We observe a delayed zircon nucleation of 500–2000 years after the melt becomes zircon saturated. Zr supersaturations that drive grown in simulations range from 1 to ∼30ppm and vary non-monotonically as crystallization proceeds. Initially, the nucleation rates increase exponentially from 10−3 to ∼1crystals/cm3/yr but then decrease by an order of magnitude as the distance between zircons decreases. Growth rates stay in 10−15cm/s range for the most duration of zircon growth. The ratio of growth to nucleation rates in our model also varies insignificantly and is used to estimate crystallization time based on the CSD slope, which decreases with the increased duration of cooling. Flatter slopes correspond to longer crystallization durations as is also noted for major phases. Due to non-monotonic variations in growth and nucleation rates with time, the observed deficiency of small zircons resulting in concave up CSD shapes can be reproduced from first principles assuming monotonic cooling of the magmatic system. Variations in the mode of cooling from linear to monotonic during conductive heat loss of a cooling intrusion, and minor coeval precipitation (<10vol%) of major phases has little impact on zircon CSD and its evolution. This study has implication to individual zircons IDTIMS dates and demonstrates that most zircons crystallize much later than magma becomes saturated with Zr, despite sometimes having nominally long tail crystallization rate in the inherited cores. For natural CSDs from eight different eruptions randomly selected zircons predate eruption age only by ∼300–1000years.

Increasing multiple cropping for land use intensification: The role of crop choice

Land use intensification increases crop production without reclaiming new cropland from natural ecosystems. In addition to the yield-improving approaches, scientists began to assess the multiple cropping potential as an alternative for intensification. These existing assessments largely focused on the number of multiple cropping frequency (MCF) while ignoring the crop growth duration (GD) required by a complete cropping circle, which may bring uncertainty on the estimates. In this study, we aim to address such uncertainty by comprehensively considering the relation between MCF and GD. Selecting Jinxian county, Jiangxi Province, as a study area, we use time-series remote sensing imageries to observe MCF and GD, and to estimate the region’s annual growing season (GS) by aggregating the crop-specific GDs corresponding to the MCF. We further apply scenario analysis to understand how crop choice. i.e. longer GD v.s. shorter GD, would influence the exploitation of GS and thus the multiple cropping potential. Results show that without considering GD, 33.63% croplands have the potential to harvest another time and 64.84% cropland could have two-extra harvests, which would result in the harvested area increased by + 163.31%. However, if GD is considered, this potential is estimated much lower in overall and is varied greatly across crop selection scenarios. In the most close-to-reality scenario, roughly 40% croplands have no potential to make extra harvest, because the GS in many areas have been largely exploited and the remaining GS is insufficient to sustain another complete crop growth. Our study shows that crop choice plays an important role in measuring and exploiting the multiple cropping potential, which provides implications for China’s “agricultural supply-side structural reform” through sustainable land use intensification.

Remote Impacts from El Niño and La Niña on Climate Variables and Major Crops Production in Coastal Bangladesh

El Niño and La Niña Southern Oscillation (ENSO) are major drivers that affect climatic variables in many countries. Therefore, ENSO mediated variation in climatic factors have significant consequences for crop production. We studied ENSO mediated variations in temperature and rainfall in the five coastal districts of Bangladesh during 1951–2017, and the impacts on major crops production were analyzed using growing degree day (GDD) index. Statistical analyses were performed on different climatic parameters in relation to ENSO events and locations. Results indicate that ENSO events had significant influence on monthly, seasonal and annual temperature and rainfall amounts (p &lt; 0.05). Specifically, maximum temperature under ENSO phases were higher during Kharif-I and Kharif-II seasons than neutral years. In contrast, the minimum temperature was higher in neutral years than ENSO events during Rabi season. Averaged across stations, annual mean maximum temperature was 0.5 and 0.23 °C higher during El Niño and La Niña compared to neutral years. Rainfall was higher during neutral years compared to El Niño and La Niña. These changes in seasonal temperature variably changed crop GDD in different locations and thus, crop growth duration and crop yield. Therefore, this study provides a general understanding to ENSO mediated impacts on coastal agriculture in Bangladesh.

Key genes and mechanisms underlying natural variation of silique length in oilseed rape (Brassica napus L.) germplasm

Silique length influences seed yield in oilseed rape. It shows extensive variation in germplasm resources, and identifying the underlying genes and regulatory mechanisms would advance breeding for the trait. In the present study, a genome-wide association study (GWAS) using 331 core accessions planted in 10 environments revealed 13 loci associated with silique length on chromosomes A01, A04, A07, A09, and C03, explaining 6.2%–19.2% of phenotypic variance. Physiological analysis showed that silique length variation was attributable to differences in silique growth rate and/or duration before four weeks after flowering, with levels of endogenous phytohormones (auxin, ethylene, and GA24, GA12, and GA44) playing an important role. Cytological analysis showed that silique length variation was due mainly to differences in cell number followed by cell size. Transcriptomic analysis of two pools of silique walls with opposite length extremes revealed 3248 differentially expressed genes (DEGs). These DEGs were enriched in several pathways (such as cell wall, cell division, and hormone metabolism) associated with cell proliferation and expansion and silique development. Integrating GWAS, RNA-seq, and functional annotation results revealed 15 candidate genes for the major associated locus qSL.A09-3. Of these, BnaA9.ARF18 and BnaA9.CYP78A9 were validated by haplotype analysis followed by candidate gene association. Sequence variation in the coding region of BnaA9.ARF18 and expression of BnaA9.CYP78A9 in silique walls were strongly associated with silique length. Our results provide an explanation for the natural variation of silique length in oilseed rape germplasm and offer useful information for its improvement.

Quantification of the pluriannual dynamics of grapevine growth responses to nitrogen supply using a Bayesian approach.

The effect of nitrogen (N) nutrition on grapevine carbon (C) dynamics has been well studied at the annual scale, but poorly addressed at a pluriannual timescale. The aim of this study was to quantify, in an integrated conceptual framework, the effect of N nutrition on potted grapevine growth and storage over 2 consecutive years. The consequences of using destructive measurements were investigated using a hierarchical Bayesian model. The rate and duration of leaf growth were both positively impacted by the chlorophyll content of the leaves, but they were negatively impacted by the initial carbohydrate measurements, raising a distortion in the estimation of initial reserves. The C production per unit of global radiation depended on the leaf area dynamics. The allocation of dry matter mainly relied on the phenological stage. The present study highlights the importance of using appropriate statistical methods to overcome uncertainties due to destructive measurements. The genericity of the statistical approach presented may encourage its implementation in other agronomy studies. Based on our results, a simple conceptual framework of grapevine pluriannual growth under various N supplies was built. This provides a relevant basis for a future model of C and N balance and responses to N fertilization in grapevine.

Preparation and characterization of colloidal Pd17Se15 nanoparticles from a novel Pd(II) pyridyl selenoether molecular precursor

An air and moisture stable Pd(II) complex with a pyridyl based selenoether ligand was synthesized and characterized with microanalysis, UV–Vis and NMR spectroscopy. The molecular structure of the complex was established by single crystal XRD analysis. The complex upon thermolysis in oleyl amine (OAm) at higher temperatures about 270 °C afforded Pd17Se15 nanoparticles of average dimensions around 14–19 nm. Phase purity, crystal structure and morphology of nanomaterials were assessed by pXRD, EDS and electron microscopy. Growth duration of nanoparticles was found to have profound effect on the particle size of Pd17Se15 nanoparticles. Time dependent studies indicate that the preparation of Pd17Se15 nanoparticles from molecular precursor proceeds via the involvement of Pd nanoparticles.

Early sowing increases grain yield and cooking and eating quality of machine‐transplanted rice in eastern China

AbstractIn this study, field experiments were conducted in 2 yr with two rice varieties to compare use of light and temperature resources, crop growth characteristics, yield traits, and cooking and eating quality of machine‐transplanted rice (Oryza sativa) in rice–wheat (Triticum aestivum) double cropping system among five sowing dates. The results showed that the total growth duration, total cumulative temperature, and total cumulative solar radiation and total biomass production from transplanting to maturity decreased with the delay in sowing date. The first sowing date (22 May) had a 1.8–11.7% higher total biomass production and 0.2–16.7% higher grain yield than the other four sowing dates (29 May, 5 June, 11 June, 18 June) across two cultivars and 2 yr. Early sowing increased leaf aera index at heading and maturity, daily mean temperature, cumulative temperature, use efficiency of cumulative temperature and solar radiation, crop growth rate, leaf area duration, and biomass production during jointing to heading and heading to maturity. Early sowing increased gel consistency, reduced amylose and protein content and increased the taste value of cooked rice. When the sowing date was delayed, rice starch Rapid Viscosity Analyzer (RVA) profile parameter, including the peak viscosity and breakdown value decreased, and the setback value increased. These results suggest that early sowing can improve use of temperature and light resources, crop growth characteristics, starch RVA spectrum characteristics, reduce rice protein content, and consequently increase biomass production, grain yield, and improve cooking and eating quality of machine‐transplanted rice in eastern China.

(Invited) Recent Progress in Large Area MOCVD Growth of 2D Materials

Metal-organic chemical vapor deposition (MOCVD) has developed to a mature production technology for state-of-the-art (opto)electronic devices such as LEDs, lasers, solar cells and transistors. Current multi-wafer MOCVD systems allow for scalable processes with precise control of growth parameters ensuring excellent uniformity of deposition rates, dopant concentrations and layer thicknesses. All of these properties are of crucial importance for reproducibly obtaining high-quality ultra-thin films required for next-generation nano-electronic devices. One of the most promising materials for the fabrication of such devices are layered transition-metal dichalcogenides (TMDCs), e.g. molybdenum disulfide (MoS2) or tungsten disulfide (WS2), graphene (Gr) or hBN. Due to their 2D structure, these materials possess unique optical, electrical and magnetic characteristics, and monolayers are considered as material system for several future applications. Moreover, the properties and functionality of a single monolayer can be even further improved by forming heterostructures of several two-dimensional materials. Such complex structures which require control on the atomic level strongly limit the number of available fabrication options, especially for volume production, leaving MOCVD as the most reliable industrial deposition method.In this work, we present wafer-scale MOCVD of high-quality monolayers of MoS2, WS2, hBN and graphene (Gr) on single-crystalline C-plane (0001) sapphire deposited in commercial AIXTRON reactors. Our upscaling effort from 2 inch wafer up to growth on 200 mm wafer supports the industrial demand. Molybdenum hexacarbonyl, tungsten hexacarbonyl and di-tert-butyl sulfide are employed as precursors. By optimizing growth conditions, fully-coalesced MoS2 and WS2 samples without parasitic carbon-related Raman peaks were obtained. XPS analysis indicates only Mo-S and W-S bonds for MoS2 and WS2 samples, respectively, with no indications of any side reactions with either the substrate, impurities or oxygen and demonstrates a high layer quality suitable for research on all kind of devices including advanced transistors and memresistive devices. Samples were characterized using Raman/photoluminescence spectroscopy, SEM and AFM to understand the correlation of growth parameter and material properties. As an example a WS2 growth duration series at 700°C temperature was performed. The intensity ratio of about 2 for the Raman E2g/A1g peaks for the optimized WS2 samples suggests deposition of monolayer WS2 with some admixture of bilayer, as confirmed by AFM. The WS2 monolayer film growth has been successfully upscaled from 2” to 200mm sapphire wafers. hBN thin films have been also grown from borazine precursor both on 2” and 200 mm sapphire substrates. Thickness uniformity of 9 nm hBN films was 3% on 200 mm wafers, as determined by XRR. High-quality monolayer graphene layers grown from CH4/H2 on 2” and 200mm sapphire wafers demonstrated good performance by Raman (2D/G peak ratio >1.5 and low D/G peak ratio (<0.25), as well as low sheet resistance (~1300-1500 Ohm/sq). The grown films had smooth surface morphology with the expected graphene wrinkles visible by AFM). These results demonstrate the applicability of AIXTRON systems for the growth of TMDC, hBN and graphene films on large size substrates. The growth could be easily upscaled from 2” to 200 mm wafer growth with only minor adjustment of the growth parameters. More details on the growth process and material properties as well as results on hBN/Gr, TMDC/Gr and TMDC/hBN heterostructures will be discussed in detail. Figure 1

The evolution of properties with deposition time of vertical graphene nanosheets produced by microwave plasma-enhanced chemical vapor deposition

In our studies, the vertical graphene nanosheets (VGN) of various heights and densities were grown on fused silica substrates by microwave plasma-enhanced chemical vapor deposition technique at different growth durations from 20 to 140 min to follow the evolution of VGN properties on the deposition time. The feedstock of the working gases and applied microwave power was kept constant focusing solely on the influence of the deposition duration. The properties and quality of VGN samples were explored by methods of scanning electron microscopy, atomic force microscopy, Raman scattering spectroscopy, and transient absorption spectroscopy (TAS). A clear correlation between the TAS results and the defectiveness and disorder of VGN layers defined by Raman scattering spectroscopy illustrates that the TAS technique can be efficiently used to describe the quality of graphene nanostructures. Increasing the deposition duration optimal growth conditions were determined ensuring the highest quality of the graphene while further increase resulted in deposits of different carbon allotropes.

Evolutionary and plastic variation in larval growth and digestion reveal the complex underpinnings of size and age at maturation in dung beetles.

Age and size at maturity are key life‐history components, yet the proximate underpinnings that mediate intra‐ and interspecific variation in life history remain poorly understood. We studied the proximate underpinnings of species differences and nutritionally plastic variation in adult size and development time in four species of dung beetles. Specifically, we investigated how variation in insect growth mediates adult size variation, tested whether fast juvenile growth trades‐off with developmental stability in adult morphology and quantified plastic responses of digestive systems to variation in food quality. Contrary to the common size–development time trade‐off, the largest species exhibited by far the shortest development time. Correspondingly, species diverged strongly in the shape of growth trajectories. Nutritionally plastic adjustments to growth were qualitatively similar between species but differed in magnitude. Although we expected rapid growth to induce developmental costs, neither instantaneous growth rates nor the duration of larval growth were related to developmental stability in the adult. This renders the putative costs of rapid growth enigmatic. We further found that larvae that encounter a challenging diet develop a larger midgut and digest more slowly than animals reared on a more nutritious diet. These data are consistent with the hypothesis that larvae invest into a more effective digestive system when exposed to low‐quality nutrition, but suggest that species may diverge readily in their reliance on these mechanisms. More generally, our data highlight the complex, and often hidden, relationships between immature growth and age and size at maturation even in ecologically similar species.

Hydrothermal growth optimization of vertically aligned ZnO nanowire arrays and their dye-sensitized solar cell performance under air/oxygen environments

In this work, the hydrothermal growth parameters of vertically aligned ZnO nanowire arrays on FTO substrates were optimized for best surface coverage and minimal stacking and entanglement between nanowires for dye-sensitized solar cell (DSSC) application. The concentration of seed layer solution was found to be essential in reducing the stacking effect of adjacent nanowires. The growth temperature study has revealed a remarkable existence of a temperature window in the range 90 °C–110 °C, beyond which the nanowire lengths start to decline. We attributed the nanowire length regression above 110 °C to the enhanced homogeneous nucleations in the growth solution. Nanowire entanglement started to be observable at ∼100 °C for a growth duration of 2 h. DSSCs were fabricated using the grown ZnO nanowire arrays that are post-annealed under air and pure oxygen gas environments. Oxygen post-annealing resulted in a remarkable decrease in the open circuit voltage (VOC), which we attributed to the large impact of band bending.

Large-scale comparison of biomass and reproductive phenology among native and non-native populations of the seagrass Zostera japonica

Large-scale analysis along latitude or temperature gradients can be an effective method for exploring the potential roles of light and temperature in controlling seagrass phenology. In this study, we investigated effects of latitude and temperature on seagrass biomass and reproductive seasonality.Zostera japonicais an intertidal seagrass with a wide latitudinal distribution expanding from tropical to temperate zones in its native range in Asia, with an additional non-native distribution in North America. We collated available data on phenological traits (timings of peak biomass or reproduction, durations of biomass growth and reproductive season, and maximum biomass or reproductive ratio) from publications and our own observations. Traits were compared among geographic groups: Asia-tropical, Asia-temperate, and North America-temperate. We further examined relationships between traits and latitude and temperature for 3 population groups: Asian, North American, and all populations. Our analysis revealed significant variation among geographic groups in maximum biomass, peak reproductive timing, and maximum reproductive ratio, but not in other traits. Maximum biomass and peak reproductive timing for Asian and all populations were significantly correlated with latitude and temperature. Maximum biomass was highest at mid-latitudes or intermediate temperatures and decreased toward distribution range limits, and peak reproductive timing occurred later in the year at higher latitudes or cooler sites. North American populations showed shorter growth durations and greater reproductive ratios at higher latitude. Different responses observed for North American populations may reflect effects of introduction. Our study demonstrates potential variation among geographic regions and between native and non-native populations.

Dating folding beyond folding, from layer-parallel shortening to fold tightening, using mesostructures: lessons from the Apennines, Pyrenees, and Rocky Mountains

Abstract. Dating syntectonic sedimentary sequences is often seen as the unique way to constrain the initiation, duration, and rate of folding as well as the sequence of deformation in the shallow crust. Beyond fold growth, however, deformation mesostructures accommodate the internal strain of pre-folding strata before, during, and after strata tilting. Absolute dating of syn-folding mesostructures may help constrain the duration of fold growth in the absence of preserved growth strata. Absolute dating of mesostructures related to early-folding layer-parallel shortening and late fold tightening provides an access to the timing and duration of the entire folding event. We compile available ages from the literature and provide new U–Pb ages of calcite cements from veins and faults from four folds (Apennines, Pyrenees, Rocky Mountains). Our results not only better constrain the timing of fold growth but also reveal a contraction preceding and following folding, the duration of which might be a function of the tectonic style and regional sequence of deformation. This study paves the way for a better appraisal of folding lifetime and processes and stress evolution in folded domains.

Структура та морфогенез пагонів видів роду Viburnum L. у Правобережному Лісостепу України

The research was conducted on the structure and characteristics of the growth of shoots of the genus Viburnum L. There are significant differences in the structure and dynamics of growth within the genus, so the determination of the structural features of the shoots of species of the genus Viburnum is relevant. The research of the dynamics of shoot growth was carried out according to the method of A.A. Molchanov and V.V. Smirnov (1967). The species studied by us belong to three sections of the genus Viburnum; the peculiarities of buds structure generally determine the structure of the shoots in the species of each section. It was found that the type of each of the three sections of the genus is characterized by a special structure of the shoots. It has been studied the rhythm of growth and development of native and introduced species of the genus Viburnum L. The terms of shoots growth of the species of the genus were analyzed, and the length of the annual growth of shoots was determined. Phenological date of the beginning and end of shoot growth was established. It was revealed that the onset of individual phenophases quite clearly correlates with the sum of effective temperatures above 5 ° C. The species of the genus Viburnum are characterized by the following types of shoots: tillering, stem, generative. Intensive growth of shoots of all studied species occurs in May - mid-June. In the species of the section Lantana, there are 2 peaks of shoot growth - May and mid-July. According to the duration of growth of shoots, viburnum can be divided into two groups: 1) with a short period of growth (65 - 75 days): V.opulus L., V.sargentii Koehne, V.prunifolium L., V.rufidulum Raf., V.lentago L; 2) with a long period of growth (100 or more days): V.lantana L., V.carlesii Hemsl., V.veitchii C.H. Wright, V.rhytidophyllum Hemsl., V.buddleifolium C.H. Wright, V.burejaeticum Rgl. et Herd. The data obtained demonstrated that the greatest annual growth of all Viburnum species was recorded at the age of 4-7 years. A decrease in the annual growth of axial shoots states the need for works on preliminary rejuvenation of the bush.

Determinants of Share Value Creation among Listed Companies in the Frankfurt Stock Exchange, Germany: Literature and Theoretical Examination

The main purpose of any firm is to enhance its shareholders’ wealth. Investors, management and other stakeholders need to be aware of the company’s performance to enable them make informed decisions about the future. The creation of shareholder value is becoming increasingly challenging as owners and managers are forced to make appropriate financial decisions that contribute to the management of operations that create value and also identify activities that destroy value. In addition it is necessary to implement effective instruments which are able to evaluate real value created. Value creation occurs in a company when its business is able to generate returns above the demands of investors or returns of capital invested are more than the cost of a company’s capital. Most financing decisions are dictated by necessity which requires in-depth analysis of financing options, costs attracted and long-term implications. A firms’ shareholder value creation is based on firms’ earnings ability and firms return on its net worth. A firm financing policy may be to choose from alternative sources, which may be internal or external. Internal financing includes use of retained earnings while external financing constitutes borrowing by issuing debt instruments and issue of new shares. The skills to identify financial variables which have the greatest impact on value creation in an organization can facilitate establishment of criteria for appropriate strategies. The study found that the main measures to quantify shareholder value creation in Germany financial sector and among listed companies are&nbsp;earnings per share (EPS), return on equity (ROE), return on assets (ROA) and dividend per share (DPS). the determinants of value creation were found to include growth rate, operating profit margin, income tax rate, working capital investment, fixed capital investment, cost of capital and value growth duration. The study recommends that the regulatory authorities in German financial sector particular should design a policy that will motivate building materials firms to be paying dividend to their shareholders on regular basis. This will increase the shareholders' value due to the nature of relation between the variables which is positive.&nbsp; Keywords: Share, Value, Creation, Listed companies, Frankfurt, Stock, Exchange. &nbsp;