Final Node Number Research Articles

A novel complex social network rumor stochastic model: Convergence in distribution to a final rumor size

We introduce a chain-binomial model in a heterogeneous complex social network (HCSN) to investigate the spread of a rumor. A novel formulation of the state of the Markov chain (MC) for the SEIR (susceptible-exposed-infected-removed) rumor epidemic model is obtained, where two discrete time measures represent individuals in their disease states both instantaneously, and also the total time duration in each state. The general MC is characterized in the HCSN, for both the mean-field and global levels of the network rumor epidemic dynamics. The convergence in distribution of the MC to the final size of the rumor epidemic random variable is fully characterized. Moreover, the algorithm to obtain the expected final number of nodes that ever hear the rumor is given. An example to demonstrate the algorithm is presented.

Sowing dates and node emission in buckwheat cultivars

The aim of this study was to determine the rate of node appearance (RNA), the final number of nodes (FNN) and the period of node emission (PNE) in two buckwheat cultivars (Fagopyrum esculentum Moench) for different sowing dates, and to check variability in the RNA, FNN and PNE between the cultivars and sowing dates. The IPR91-Baili and IPR92-Altar cultivars were evaluated for 29 and 31 sowing dates from October to May in the 2017/2018 and 2018/2019 agricultural years respectively. In each experiment, a completely randomised design with five replications was used. The number of nodes (NN) on the main stem was counted twice a week in each plant (replication), from emission of the first node until the end of the cycle. The linear regression (y = a + bx) of the number of nodes (NN, y) was adjusted for each plant based on the number of days after emergence (DAE, x). The rate of node appearance (RNA), in days node-1, was determined from the inverse of the slope of the linear regression between NN and DAE (RNA = 1/b). The RNA was calculated for the period of node emission (PNE, in days), i.e. from emergence to emission of the last node. The final number of nodes (FNN) was counted at the end of node emission. Variability was found in the rate of node appearance (RNA), the final number of nodes (FNN) and the period of node emission (PNE) between the cultivars and sowing dates. The rate of node appearance ranges between 2.20 and 8.23 days node-1, the final number of nodes between 2.20 and 17.20, and the period of node emission between 16.60 and 49.20 days. Plants of the IPR91-Baili and IPR92-Altar cultivars show better vegetative development (lower RNA, higher FNN and greater PNE) when sown in November, December, January and February, compared to those sown in October, March, April and May.

Phenology and productive performance of chamomile in sowing dates and spacing between plants

The present work has aimed to evaluate phenology and productive performance of chamomile in a subtropical weather region, sown in different dates and spacings in between plants. The experiment took place in Santa Maria – RS with four sowing dates in the year 2017 (18/03, 28/04, 30/06 and 31/08) and seven spacings along plants in rows (5, 10, 15, 20, 25, 30 and 40 cm), spaced 30 cm between each other. Phenological observations were made every two or three days in two plants per portion while also accounting for the number of nodes in the main stem. The harvest of chamomile floral chapters was performed manually from the beggining of flowering and repeated biweekly until plant maturation. Productivity of dry floral chapters as well as content and productivity of essential oils were evaluated. It was established that sowing dates affect the productivity of dry floral chapters, content and productivity of essential oil from cv. Mandirituba chamomile, with the sowings of March 18th and April 28th presenting the highest values for such variables. Increasing the space between plants from the 10 cm line to 40 cm in lines spaced in 30 cm has shown a linear tendency of decreasing the productivity of dry floral chapters. Spacings between plants did not affect the phenological development of chamomile, however, sowing dates interfered in the thermal time of six evaluated subperiods regarding plastochron and the final number of nodes.

Influence of Air Temperature in the Emission of Nodes, Ramifications and Flowers in Hybrids of Watermelon (Citrullus lanatus)

The culture of watermelon develops mainly under conditions of high temperature, being the temperature an element that directly affects the emission of vegetative and reproductive organs. There are no reports of the accumulation of temperature required for emission of branches, nodes and flowers. Thus, this experiment aimed to evaluate the rate of emission of vegetative and reproductive organs for hybrids of watermelon in relation to air temperature, using the hybrids of Manchester and Top Gun watermelons. The experiment was conducted in Federal University of Santa Maria, campus Frederico Westphalen-RS, from September to December 2014. Evaluations were conducted at every two days and it was determined the variables: nodes emission, final number of nodes on the main stem, number of primary and secondary ramifications and number of staminate flowers and open pistillate flowers related to accumulated thermal sum for the emission of such organs, and the ratio between the number of staminate flowers to the pistillate. The hybrids of watermelon present for plastochron of 18.8 °C node day, final number of nodes of the main ramification of 43 and number of primary and secondary ramifications of eight and 20, respectively. For the emission of staminate and pistillate flowers the hybrids need an accumulation 10.5 and 46.7 °C day, respectively. The number of staminate and pistillate flowers is 52 and nine, respectively, and the ration between flowers of 6.6:1.

Weed incidence and sowing time affect soybean development

Despite the economic importance of the effects of weeds on the plastochron and emission of nodes of soybean plants, it has not been studied in detail. The aim of this study was to provide information about the effects of weeds on the development of soybean plants by determining the plastochron and number of nodes of soybean plants of different cultivars sown at different times in soils with presence and absence of weeds. A field study was conducted during the 2013/2014 crop season including a phytosociological survey to identify the occurring weeds, and the determination of the plastochron and final number of nodes of soybean plants. Four botanical families of weeds were found infesting the soybean crops. The plastochron and final number of nodes of soybean were influenced by the cultivar, sowing time, and presence of weeds. The plastochron was higher when the plants were grown in the presence weeds due to the higher relative frequency, relative density, relative abundance, and importance value index of the Euphorbia heterophyla, Ipomoea purpurea, and Urochloa plantaginea species, which resulted in a slower development of the soybean plants, and lower number of nodes per plant.

Growth, Plastochron, and the Final Number of Nodes of China Pink Seedlings Grown on Different Substrates

ABSTRACT The objective of this work was to plot the growth curves and determine the plastochron and the final number of nodes of China pink seedlings grown on different substrates. Thus, 392 China pink seedlings were grown on seven substrates under greenhouse conditions, in Santa Maria in the state of Rio Grande do Sul, Brazil. The growth curves were plotted using the logistic model. The plastochron was estimated by the inverse of the angular coefficient of the simple linear regression between the number of accumulated nodes and accumulated thermal sum from the subsampling of the seedlings. In all substrates, the logistic model fit better for the variable number of leaves than for the plant height. The plants in substrates with 50% of soil plus 50% of rice husk ash, and 80% of rice husk ash plus 20% earthworm humus had the longest cycles with 74 and 65 days, respectively. They completed the cycles with a thermal sum of 1317.9 ºC day for number of leaves and plant height. The growth curves that were plotted by the logistic model and the plastochron of the China pink seedlings are dependent on the type of substrate used. The commercial substrate Mecplant® had the best results. The average final number of nodes of the main stem of the plants was 14 for all substrates.

Extending the evaluation of the SoySim model to soybean cultivars with high maturation groups

SoySim is a dynamic process-based model for soybean that requires fewer genotype-specific parameters compared to other soybean models such as the CROPGRO-Soybean model. The SoySim model was originally developed and evaluated using cultivars with maturity group (MG) ratings from 0.8 to 4.2 in temperate climate and mid latitudes. The objective of this study was to evaluate the SoySim model for simulating growth, development and yield of soybean cultivars with MG greater than 4.2 grown in the subtropics of Southern Brazil. The range of maturity groups used in this study was from 4.8 to 8.2, including indeterminate and semi-determinate soybean cultivars. Data for model evaluation were from well-managed twelve field experiments across the Rio Grande do Sul State, including on-farm experiments, during five growing seasons (2010/2011–2014/2015), with sowing dates before, during and after the recommended period, and yield ranging from 1.5 to 5.9Mgha−1. The errors in the prediction of final node number, R-stages, LAI and seed yield were high mainly for soybean cultivars with maturation group greater than 6, indicating weaknesses of the model in simulating growth and development of cultivars in environment outside the range where the model was calibrated. We conclude that there is a need to review parameters and relationships in the SoySim model to better describe the effect of environment factors, such as temperature and photoperiod, on growth and development of soybean cultivars with maturity group greater than 6, typically used in the tropics and subtropics.

Next generation crop models: A modular approach to model early vegetative and reproductive development of the common bean (Phaseolus vulgaris L)

The next generation of gene-based crop models offers the potential of predicting crop vegetative and reproductive development based on genotype and weather data as inputs. Here, we illustrate an approach for developing a dynamic modular gene-based model to simulate changes in main stem node numbers, time to first anthesis, and final node number on the main stem of common bean (Phaseolus vulgaris L.). In the modules, these crop characteristics are functions of relevant genes (quantitative trait loci (QTL)), the environment (E), and QTL×E interactions. The model was based on data from 187 recombinant inbred (RI) genotypes and the two parents grown at five sites (Citra, FL; Palmira, Colombia; Popayan, Colombia; Isabela Puerto Rico; and Prosper, North Dakota). The model consists of three dynamic QTL effect models for node addition rate (NAR, No. d−1), daily rate of progress from emergence toward flowering (RF), and daily maximum main stem node number (MSNODmax), that were integrated to simulate main stem node number vs. time, and date of first flower using daily time steps. Model evaluation with genotypes not used in model development showed reliable predictions across all sites for time to first anthesis (R2=0.75) and main stem node numbers during the linear phase of node addition (R2=0.93), while prediction of the final main stem node number was less reliable (R2=0.27). The use of mixed-effects models to analyze multi-environment data from a wide range of genotypes holds considerable promise for assisting development of dynamic QTL effect models capable of simulating vegetative and reproductive development.

Nodal counts during pelvic lymph node dissection for prostate cancer: an objective indicator of quality under the influence of very subjective factors

Study Type--Therapy (case series). Level of Evidence 4. What's known on the subject? And what does the study add? In lymph node dissections for cancer, the more extended the dissection, the higher the number of lymph nodes removed. In addition, the higher the number of nodes retrieved, the better the staging. This leads many investigators to set a threshold of a minimal number of nodes below which the dissection is considered inadequate. Although the minimal threshold concept is generally good, it is not based on very objective data. a number of factors might influence the final number of nodes removed: (i) the surgeon and the surgical technique; (ii) the pathologists and tissue processing technique; (iii) the patient; and (iv) the audit effect and feedback to the surgeons about the number of nodes removed. • To examine the number of lymph nodes removed over time for men undergoing a standard pelvic lymph node dissection (PLND) during radical prostatectomy. • In total, 2119 consecutive patients with clinically localized prostate cancer were scheduled for non-salvage radical prostatectomy between February 2005 and September 2009. • All patients underwent PLND, including the external iliac, hypogastric and obturator fossa nodal groups. • We tested whether the number of lymph nodes increased over time by including the date of each patient's surgery into a linear regression model using nonlinear terms. • From 2008 onward, there appears to be a large increase in the number of nodes removed. • Date of surgery was a significant predictor of the number of nodes removed (P < 0.001). • The anatomical template of dissection, the specimen submission and pathological assessment were reportedly unchanged. • The nodal yield increase in the later part of the study coincides with an increase in the academic interest in PLND and nodal metastasis in prostate cancer at the institutional level and worldwide. • Without any intentional change in surgical technique or pathological processing, the number of lymph nodes removed in our radical prostatectomy experience increased. • This change coincided with an increased academic interest in the subject and highlights the positive feedback effect. • The change also raises concerns about unaccounted for confounding factors that could affect multi-institutional datasets and surgical clinical trials.

Plastocrono e número final de nós de cultivares de soja em função da época de semeadura

O plastocrono, intervalo de tempo entre o aparecimento de dois nós sucessivos na haste principal da planta, e o número final de nós (NFN) são importantes variáveis do desenvolvimento de plantas. O objetivo deste trabalho foi determinar o plastocrono e o NFN de cultivares de soja (Glycine max (L.) Merrill) semeadas em diferentes épocas em um local de clima subtropical. Um experimento de campo foi realizado em Santa Maria, RS, no ano agrícola de 2005/2006, com três épocas de semeadura (09/11/2005, 09/12/2005 e 28/01/2006). Foram utilizadas 15 cultivares de soja recomendadas para as regiões Norte e Centro da Argentina, e Sul e Sudeste do Brasil. As variáveis medidas foram o número acumulado de nós (NN) e o NFN na haste principal. O plastocrono foi estimado pelo inverso do coeficiente angular da regressão linear entre o NN e a soma térmica acumulada a partir de emergência (temperatura base = 10°C). Semeaduras tardias resultaram em menor plastocrono e menor NFN, provavelmente devido ao menor fotoperíodo a que as plantas foram submetidas durante a fase de emissão de nós, uma resposta característica de plantas de dia curto.

Temperatura base, plastocrono e número final de nós no malmequer-do-campo

O malmequer-do-campo (Aspilia montevidensis) é uma planta herbácea perene, nativa do Sul e Sudeste do Brasil, cuja biologia tem sido pouco estudada. O objetivo deste trabalho foi determinar a temperatura base, o plastocrono e o número final de nós de A. montevidensis. Para tanto, foi conduzido um experimento em Santa Maria, RS, com seis épocas de cultivo (20/12/2005, 14/02/2006, 06/03/2006, 04/04/2006, 05/05/2006 e 08/06/2006) no delineamento inteiramente casualizado. A unidade experimental foi uma planta cultivada em vasos preenchidos com substrato comercial. O número de nós visíveis foi registrado na haste principal e nas hastes laterais de primeira e segunda ordem. A temperatura base de emissão de nós foi estimada pela metodologia do menor Quadrado Médio do Erro. A soma térmica diária foi calculada a partir do transplante e o plastocrono foi estimado para cada haste. A temperatura base estimada para emissão de nós de A. montevidensis foi de 0°C. O plastocrono e o número final de nós variam entre hastes e épocas de cultivo, com os menores valores de plastocrono e maiores valores de número final de nós observados na haste principal.

Understanding and modeling the effect of temperature and daylength on soybean phenology under high-yield conditions

Temperature and photoperiod can be used to simulate soybean ( Glycine max [L.] Merr) phenology because they serve as surrogates for complex biochemical pathways leading to the appearance of certain developmental stages at the whole plant level. We developed a soybean phenology model (SOYDEV) which utilizes non-linear temperature and photoperiod functions and separates floral induction and post-induction for simulating time of flowering. This model accurately simulated the dynamics of vegetative development, final node number and the occurrence of major reproductive stages such as flowering (R 1), beginning pod (R 3), mid-pod elongation (R 3.5), beginning seed (R 5), and physiological maturity (R 7) in a long-term field experiment (6 years) with the semi-determinate soybean cv. NE3001, as well as in a 2-year cultivar × sowing date experiment with 12 (2004) and 8 (2005) cultivars. With cultivar-specific model calibration, root mean square errors (RMSE) of major phenological stages simulated with SOYDEV averaged 1.8 days in the long-term experiment and 3.3 days in the cultivar × sowing date experiment. Data from the cultivar × sowing date experiment were used to develop empirical relationships for estimating key cultivar-specific model parameters from published soybean maturity group ratings (0.8–4.2). Compared to using nine cultivar-specific parameters derived from the full calibration, estimation of model parameters from readily available cultivar information such as maturity group rating only slightly decreased simulation accuracy, resulting in RMSE (across stages and cultivars) values of 3.6–3.8 days. The proposed SOYDEV model may be particularly suitable for practical model applications because of its reduced need for cultivar-specific calibration. Further evaluation of the model is required under a wider range of variety maturity group ratings and environments.

Agronomic and Phenological Differences of Soybean Isolines Differing in Maturity and Growth Habit

The effects of maturity genes (E genes) on flowering, maturity, and the seed filling period of soybean [Glycine max(L.) Merr.] have previously been described. However, little work has been done to quantify the effect of maturity and growth habit genes on morphological and phenotypic traits. This study quantifies the effects of maturity and growth habit genes on morphological and phenotypic traits to understand better how these genes may be most agronomically beneficial in northern short‐season breeding programs. Four near‐isogenic pairs consisting ofe1e3e4,e1e3E4,e1E3E4, andE1e3e4maturity gene combinations containing either indeterminate (Dt1) or determinate (dt1) stem termination type were grown near Woodstock, ON, in 1994 and 1995. When averaged across growth habit, the presence of an additional dominant maturity gene significantly increased the time to the start of the seed filling period (SSFP) and days to maturity. Lines with dominant E genes exhibited increased height, final node number, and lodging, and decreased harvest index. Indeterminate growth habit caused increased days to SSFP in 1995, and increased days to maturity, height, and lodging and decreased harvest index in both years. A positive relationship between whole‐plant seed filling rate (SFR) and yield occurred in theDt1lines in both years and occurred in thedt1lines in 1994. There was a positive relationship between whole‐plant seed filling period (SFP) and yield in thedt1lines in 1995. TheE1dt1line consistently had the highest seed filling rate of any isoline. The data indicated that theE1dt1combination may have unrealized potential in short‐season breeding programs.

The evolution of tolerance to damage in Gentianella campestris: natural selection and the quantitative genetics of tolerance

In the framework of phenotypic plasticity, tolerance to browsing can be operationally defined as a norm of reaction comparing plant performance in undamaged and damaged conditions. Genetic variation in tolerance is then indicated by heterogeneity in the slopes of norms of reaction from a population. We investigated field gentian (Gentianella campestris) tolerance to damage in the framework of phenotypic plasticity using a sample of maternal lines from natural populations grown under common garden conditions and randomly split into either a control or an artificial clipping treatment. We found a diversity of tolerance norms of reaction at both the population and family level: the impacts of clipping ranged from poor tolerance (negative slope) to overcompensation (positive slope). We detected heterogeneity in tolerance norms of reaction in four populations. Similarly, we found a variety of plastic architectural responses to clipping and genetic variation in these responses in several populations. Overall, we found that the most tolerant populations were late flowering and also exhibit the greatest plastic increases in node (meristem) production in response to damage. We studied damage-imposed natural selection on plasticity in plant architecture in 10 of the sampled populations. In general, there was strong positive direct selection on final number of nodes for both control and clipped plants. However, the total selection on nodes (direct + indirect selection) within each treatment category depended heavily on the frequency of damage and cross-treatment genetic correlations in node production. In some cases, strong correlated responses to selection across the damage treatment led to total selection against nodes in the more rare environment. This could ultimately lead to the evolution of maladaptive phenotypes in one or both of the treatment categories. These results suggest that tolerance and a variety of architectural responses to damage may evolve by both direct and indirect responses to natural selection. While the present study demonstrates the potential importance of cross-treatment genetic correlations in directing the evolution of tolerance traits, such as branch or node production, we did not find any strong evidence of genetic trade-offs in candidate tolerance traits between undamaged and damaged conditions.

APPLE BUD DEVELOPMENT AS INFLUENCED BY ROOTSTOCK

Apple flower formation was studied on mature `Starkspur Supreme Delicious' apple trees growing on 5 rootstocks: B.9, M.26 EMLA, M.7 EMLA, P.18, and seedling. In 1991 and 1992 buds were sampled from the previous seasons growth and dissected. In 1991 10-20% of the buds from trees on M.26 EMLA, P. 18 and seedling rootstocks formed flowers whereas flowers were evident in about 50% of the buds from B.9 and M.7 EMLA trees. In 1992 however, over 90% of buds from trees on all rootstocks formed flowers. Despite very different environmental conditions and degree of flower formation, flower differentiation occurred between 80-110 days after full bloom in both years and among all rootstocks. The critical number of nodes present in buds prior to the appearance of flowers was 18-19 and was not influenced by rootstock. Increases in node number over the course of a season was primarily due to increases in the number of bracts present in the bud. In 1991 (a season characterized by high temperatures and low rainfall) buds from trees growing on B.9 and M.7 EMLA rootstocks exhibited a higher final node number and a greater degree of flower initiation than buds from other trees, but no differences were observed during the more favorable conditions in 1992.

Maintenance of 2- and 3-edge- connected components of graphs I

In this paper, a data structure is presented to efficiently maintain the 2- and 3-edge-connected components of a graph, under insertions of edges in the graph. Starting from an ‘empty’ graph of n nodes, the insertion of e edges takes O( nlog n+ e) timein total. The data structure allows for insertions of nodes also (in the same time bounds, taking n as the final number of nodes). Moreover, at any moment, the data structure can answer the following type of query in O(1) time: given two nodes in the graph, are these nodes 2- or 3-edge-connected.

The Effects of Daminozide and Gibberellic Acid on Flower Initiation, Growth and Fruiting of Apple cv Golden Delicious

SummaryNodes were produced at the same rate in all buds of Golden Delicious apple until about 10 weeks after full bloom. Production then became slower and ceased at about 16 nodes in buds which remained vegetative. In buds destined to become floral, primordium production suddenly became faster, leading to a final node number of about 21. This increased rate of node production was detected one to two weeks before the first visible signs of flower differentiation. Applying 550 ppm GA3 or 2000 ppm daminozide at 14 or 39 days after full bloom did not influence the rate of node production, but GA3 decreased, and daminozide increased, the proportion of floral buds. The early application of daminozide increased the crop in the year of application, because it reduced June drop, and in the next year because it enhanced flower number. In the third year, however, fewer blossoms were produced, a reduction not fully explained by the heavier crop and reduced tree growth in the previous year.