On the Age and Growth Rate of Giant Cacti: Radiocarbon Dating of the Spines of Cardon (Pachycereus Pringlei)

Radiocarbon ◽  
2016 ◽  
Vol 58 (3) ◽  
pp. 479-490 ◽  
Author(s):  
Mariana Delgado-Fernández ◽  
Pedro P Garcillán ◽  
Exequiel Ezcurra
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Annual Growth ◽  
Age And Growth ◽  
Limiting Factor ◽  
Annual Growth Rate ◽  
Columnar Cacti ◽  
Rate Versus ◽  
The Mean ◽  
Pachycereus Pringlei

AbstractAge estimation has been a limiting factor in the study of giant columnar cacti. In order to test the feasibility of using radiocarbon methods to estimate the age of the giant cardon cacti (Pachycereus pringlei), we selected six sites spanning the latitudinal and precipitation range of the species in the Baja California peninsula. In each site, we selected four individuals of different heights and sampled a spine from the lowest areole in the stem. The age of the spine was estimated using 14C dating, and the mean annual growth rate of the plant was calculated dividing the height of the lead shoot by the plant’s age. Mean annual growth rate was 0.098 m/yr, with values varying between 0.03 and 0.23 m/yr. Within the range of plants sampled, mean annual growth rates were significantly correlated with the height of the plant (r2=0.82, P<0.0001), and no other site-specific variable such as precipitation or latitude was a significant predictor of mean annual growth rates. A model integrating mean growth rate versus height showed that relatively small differences in growth rates between plants accumulate during the plants’ lifetime, so that plants of similar size may have very different ages. We conclude that 14C dating provides a robust method to explore the growth and demography of columnar cacti.

scholarly journals Phenology and growth indicators of honey trees and bushes in Uzbekistan

2021 ◽  
Vol 244 ◽  
pp. 02050
Author(s):  
J. M. Jumayev ◽  
M. Z. Kholmurodov ◽  
K. A. Khalilova
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Annual Growth ◽  
Annual Growth Rate ◽  
Flowering Period ◽  
Lycium Barbarum ◽  
Sophora Japonica ◽  
Symphoricarpos Albus ◽  
Trees And Shrubs ◽  
Growth Indicators

This article presents the results of research on the study of some bioecological properties of honey-producing trees and shrubs. The flowering period of the main trees and shrubs is March-June and allows to obtain a high amount of honey. During the summer months, Lycium barbarum, Symphoricarpos albus, Sophora japonica species continue to bloom until autumn. According to the data, the growth rates of all trees and shrubs were at the level of demand. In particular, when growing linden trees in the spring, their height increased from 190.5 cm to 230.5 cm in autumn. That was, it grew by 40 cm during one vegetation. The Ligustrum bush had the highest growth rate, with seedlings planted in spring averaging 90 cm in height and 155.8 cm in autumn, with an annual growth rate of 65.8 cm. These indicators depicted that the conditions in the experimental fields were suitable for the growth of trees and shrubs.

scholarly journals Analysis of Trends, Growth and Instability in Rice Production in Andhra Pradesh

2020 ◽  
pp. 40-46
Author(s):  
G. P. Sunandini ◽  
K. Solmon Raju Paul ◽  
Shakuntala Devi Irugu
Keyword(s):  
Growth Rate ◽  
Productivity Growth ◽  
Growth Rates ◽  
Sustainable Management ◽  
Andhra Pradesh ◽  
Management Practices ◽  
Annual Growth ◽  
Annual Growth Rate ◽  
High Productivity ◽  
The Past

The study has been taken up with the objective of investigating the trends, pattern of growth and the extent of instability in area, production and productivity of rice crop in Andhra Pradesh state over a period of five and half decades from 1959-60 to 2013-14. Compound Growth Rate and Coefficient of Variation were used to calculate the annual growth rate and instability. The area, production and productivity of rice in this period has increased by 25, 201 and 138 per cent respectively. In this period, the districts were categorised and grouped under different groups based on average productivity of rice. During the study period many of the districts moved from very low productivity to high productivity group. During 1960s, 17 districts are under very low productivity group (<1500 kg/ha) and in 2010s 13 districts are under high productivity group (>3000 kg/ha). During the period 2014-19 in the divided Andhra Pradesh contribution of different productivity groups to the states paddy production was calculated and concluded that 3 districts under high productivity group (>6000kg/ha) contributed 52 per cent of the production. During 2010s annual growth rates for area, production and productivity are 4.08, 4.02 and 1.21 respectively. In all the periods in the past five and half decades, production and productivity growth rates are higher than growth rate in area except in 2010s. Instability was higher in production and area than in productivity.  The annual growth rate and the instability of production and area are higher in 2010s. Suitable crop planning is to be initiated, adoption of sustainable management practices are to be intensified to maintain the growth rate and reduce the instability in area and production.

Two-year tree growth patterns investigated from monthly girth records using dendrometer bands in a wet evergreen forest in India

2000 ◽  
Vol 16 (3) ◽  
pp. 429-446 ◽  
Author(s):  
Raphaël Pélissier ◽  
Jean-pierre Pascal
Keyword(s):  
Growth Rate ◽  
Tree Growth ◽  
Growth Patterns ◽  
Annual Growth ◽  
Evergreen Forest ◽  
Annual Growth Rate ◽  
Growth Data ◽  
Growth Profiles ◽  
Dendrometer Bands ◽  
The Mean

With the aim of characterizing tree growth patterns, this paper re-examines the growth data of 100 selected trees belonging to 24 species that were recorded monthly in a 0.2-ha plot of a wet evergreen forest in the Western Ghats of India during the period 1980–82 using dendrometer bands. The mean growth profile, combining all of the selected trees, showed: (a) a significantly lower annual growth rate during the second year of survey which seemed to be negatively related to monsoon precipitation; (b) significant intra-annual growth variation clearly related to the regular alternation between a period of heavy rain and a quite long dry season of the monsoon climatic regime. Analysis of the variability of the individual smoothed growth profiles representing the 2-y trend of the growth data showed that: (a) the mean growth rate depended on a combination of an intrinsic endogenous variable (the structural class grouping species according to their maximum size), a tree size variable (tree diameter at breast height, dbh) and a neighbourhood variable (the number of taller neighbours in a 10-m radius); (b) the sudden change in growth rate from one year to the other was not predictable using these variables. The amplitude of the seasonal variations, investigated from the detrended growth profiles, appeared to be dependent on a combination of tree dbh and the number of taller neighbours in a 10-m radius. A co-inertia analysis of the smoothed and the detrended growth profiles indicated that the trees with fast growth also exhibited high seasonal variation. It is suggested that fast growing trees are those with favourable crown positions, which are consequently subject to high transpiration rates due to radiation and wind exposure.

scholarly journals Growth and Instability in Production and Export of Almond in Afghanistan

2021 ◽  
Vol 04 (04) ◽  
Author(s):  
Abdul Wahid Sultani ◽  
Keyword(s):  
United States ◽  
Growth Rate ◽  
Growth Rates ◽  
The United States ◽  
Annual Growth ◽  
Annual Growth Rate ◽  
World Production ◽  
Compound Annual Growth Rate ◽  
Year 2000 ◽  
High Instability

The almond is native to Iran and surrounding countries as well as Asia. In 2017, world production of almonds was 2.2 million tones, with the United States providing 46% of the total. According to FAO Afghanistan is one of the 10 top producers of almonds. The study examined the growth and instability of area, production, export and consumption of almond in Afghanistan from 2000 to 2017. Exponential function fitted to estimate compound annual growth rates (CAGR) in area, production, export and consumption of almond, and Cuddy – Della Valle indices are used in the study. The compound growth rates for area, production and productivity of almonds in Afghanistan were 5.77 %, 7.37 % and 1.52 % respectively. Area under almond crop exhibited medium (19,52) instability, where production and productivity shown high (50.05 and 49.01) instability respectively, during this period. Almond consumption grew by 6.75 per cent and export grew with compound annual growth rate of 6.12 per cent from the year 2000 to 2017.Both export and consumption of almond registered high instability in this period.

scholarly journals Dynamics of Canadian Trade Pattern: A Time-Series Analysis

2017 ◽  
Vol 9 (3) ◽  
pp. 115
Author(s):  
Hussein Al-Zyoud ◽  
Fathi Elloumi
Keyword(s):  
Growth Rate ◽  
Time Series ◽  
Growth Rates ◽  
Annual Growth ◽  
Series Data ◽  
Annual Growth Rate ◽  
Instantaneous Rate ◽  
Compound Annual Growth Rate ◽  
Long Run ◽  
Log Linear

This paper analyses the trends and directions of exports and imports of Canada using the time series data for the period 1981 to 2014. Instantaneous and compound growth rates are calculated by using the log-linear regression model in conjunction with an autoregressive integrated moving average (ARIMA) model for forecasting future exports and imports. The results of this study show that there is an increasing trend for both exports and imports. As far as the growth rates are concerned, the two estimated log-linear models depict a comprehensive annual picture of Canadian merchandise trade. The exports grow at an instantaneous rate of 4.46% and at a slightly higher than compound annual growth rate of 4.6%. The overall growth rate of imports is 5.41% and compound annual growth rate is 5.27%. The compound growth rate is marginally higher than the instantaneous growth rate.The results of the Johansen test for analyzing the long-run relationship between export, import and GDP have further demonstrated that the variables are co-integrated, and have established a long-run association among them.

Volumetric growth rates of untreated cavernous sinus meningiomas

2021 ◽  
pp. 1-8
Author(s):  
Carolina Gesteira Benjamin ◽  
Zane Schnurman ◽  
Kimberly Ashayeri ◽  
Eman Kazi ◽  
Reed Mullen ◽  
...  
Keyword(s):  
Growth Rate ◽  
Cavernous Sinus ◽  
Growth Rates ◽  
Growth Pattern ◽  
Observation Interval ◽  
Annual Growth ◽  
Patient Treatment ◽  
Annual Growth Rate ◽  
Mr Images ◽  
Volumetric Growth

OBJECTIVE Meningiomas that arise primarily within the cavernous sinus are often believed to be more indolent in their growth pattern. Despite this perceived growth pattern, disabling symptoms can arise even with small tumors. While research has been done on cavernous sinus meningiomas (CSMs) and their treatment, very little is known about their natural growth rates. With a better understanding of the growth rate of CSM, patient treatment and guidance can be can optimized and individualized. The goal of this study was to determine volumetric growth rates of untreated CSMs. METHODS Thirty-seven patients with 166 MR images obtained between May 2004 and September 2019 were reviewed, with a range of 2–13 MR images per patient (average of 4.5 MR images per patient). These scans were obtained over an average follow-up period of 45.9 months (median 33.8, range 2.8–136.9 months). All imaging prior to any intervention was included in this analysis. Volumetric measurements were performed and assessed over time. RESULTS The estimated volumetric growth rate was 23.3% per year (95% CI 10.2%–38.0%, p < 0.001), which is equivalent to an estimated volume doubling time (VDT) of 3.3 years (95% CI 2.1–7.1 years). There was no significant relationship between growth rate and patient age (p = 0.09) or between growth rate and patient sex (p = 0.78). The median absolute growth rate was 41% with a range of −1% to 1793%. With a definition of “growth” as an increase of greater than 20% during the observed period, 65% of tumors demonstrated growth within their observation interval. Growth rates for each tumor were calculated and tumors were segmented based on growth rate. Of 37 patients, 22% (8) demonstrated no growth (< 5% annual growth, equivalent to a VDT > 13.9 years), 32% (12) were designated as slow growth (annual growth rate 5%–20%, VDT 3.5–13.9 years), 38% (14) were found to have medium growth (annual growth rate 20%–100%, VDT 0.7–3.5 years), and 8% were considered fast growing (annual growth rate > 100%, VDT < 0.7 years). CONCLUSIONS This study evaluated CSM volumetric growth rates. A deeper understanding of the natural history of untreated CSMs allows for better counseling and management of patients.

Growth rate and chemical features of the massive calcium carbonate skeleton of Petrobiona massiliana (Baeriida: Calcaronea: Calcispongiae)

2009 ◽  
Vol 90 (4) ◽  
pp. 749-754 ◽  
Author(s):  
Julie Hermans ◽  
Philippe Dubois ◽  
Luc Andre ◽  
Jean Vacelet ◽  
Philippe Willenz
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Annual Growth ◽  
Epifluorescence Microscopy ◽  
Annual Growth Rate ◽  
Growth Mechanisms ◽  
Active Growth ◽  
Magnesium Calcite ◽  
Discontinuous Growth

In addition to the spicules typically produced by sponges, about twenty hypercalcified species belonging to both classes Demospongiae and Calcispongiae secrete a massive basal calcareous skeleton composed of calcite or aragonite. Skeletal growth rates and growth mechanisms are still poorly known in those hypercalcified Calcispongiae. In situ calcein staining experimentation on the Mediterranean calcisponge Petrobiona massiliana revealed a mean annual growth rate of the massive skeleton of 236 µm/y (±90). Scanning electron microscopy (SEM) revealed that some spicules are entrapped within the massive skeleton (a solid mass forming apical crests with multidirectional growth axes) during its formation. Whole actines were observed within the massive skeleton of fractured specimens, indicating that they do not dissolve after entrapping. Calcein incorporation bands seen through epifluorescence microscopy and SEM morphological observations of the skeletal surface revealed cone shaped protuberances corresponding to active growth areas. A spatially discontinuous growth was highlighted, but the annual growth rates were similar at the tip of crests and at the bottom of depressions separating them. The skeleton of P. massiliana is composed of magnesium calcite with strontium as the main trace element. Significant differences in skeletal chemistry of specimens collected in different Mediterranean locations revealed a possible temperature dependence of Mg/Ca. Although such temperature signature exists in the massive skeleton of P. massiliana, its use as an accurate environmental recorder is limited by several factors including multidirectional and spatially discontinuous growth.

Ageing Saudi Population in the Facebook Era

2018 ◽  
Author(s):  
Asharaf Abdul Salam
Keyword(s):  
Growth Rate ◽  
Saudi Arabia ◽  
Population Ageing ◽  
Annual Growth ◽  
Annual Growth Rate ◽  
Saudi Population ◽  
Aged Population ◽  
Facebook Usage

<p>Data pertaining to 1974, 1992, 2004 and 2010 Censuses in Saudi Arabia was collected. Some reviews and literature on population ageing in Saudi Arabia as well as Facebook usage obtained. Statistics pertaining to Saudi population was utilized.</p> <p>Aged population in 2010 estimated by assuming the annual growth rate of 1974-2004.</p>

scholarly journals Association between triglyceride-glucose index and risk of arterial stiffness: a cohort study

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Shouling Wu ◽  
Luli Xu ◽  
Mingyang Wu ◽  
Shuohua Chen ◽  
Youjie Wang ◽  
...  
Keyword(s):  
Growth Rate ◽  
Linear Regression ◽  
Arterial Stiffness ◽  
Multivariate Linear Regression ◽  
Annual Growth ◽  
Annual Growth Rate ◽  
Cross Sectional ◽  
Tyg Index ◽  
Longitudinal Association ◽  
The Cross

Abstract Background Triglyceride–glucose (TyG) index, a simple surrogate marker of insulin resistance, has been reported to be associated with arterial stiffness. However, previous studies were limited by the cross-sectional design. The purpose of this study was to explore the longitudinal association between TyG index and progression of arterial stiffness. Methods A total of 6028 participants were derived from the Kailuan study. TyG index was calculated as ln [fasting triglyceride (mg/dL) × fasting glucose (mg/dL)/2]. Arterial stiffness was measured using brachial-ankle pulse wave velocity (baPWV). Arterial stiffness progression was assessed by the annual growth rate of repeatedly measured baPWV. Multivariate linear regression models were used to estimate the cross-sectional association of TyG index with baPWV, and Cox proportional hazard models were used to investigate the longitudinal association between TyG index and the risk of arterial stiffness. Results Multivariate linear regression analyses showed that each one unit increase in the TyG index was associated with a 39 cm/s increment (95%CI, 29–48 cm/s, P < 0.001) in baseline baPWV and a 0.29 percent/year increment (95%CI, 0.17–0.42 percent/year, P < 0.001) in the annual growth rate of baPWV. During 26,839 person-years of follow-up, there were 883 incident cases with arterial stiffness. Participants in the highest quartile of TyG index had a 58% higher risk of arterial stiffness (HR, 1.58; 95%CI, 1.25–2.01, P < 0.001), as compared with those in the lowest quartile of TyG index. Additionally, restricted cubic spline analysis showed a significant dose–response relationship between TyG index and the risk of arterial stiffness (P non-linearity = 0.005). Conclusion Participants with a higher TyG index were more likely to have a higher risk of arterial stiffness. Subjects with a higher TyG index should be aware of the following risk of arterial stiffness progression, so as to establish lifestyle changes at an early stage.

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