scholarly journals Biologi dan statistik demografi kutudaun Rhopalosiphum rufiabdominale (Sasaki) dan Tetraneura nigriabdominalis (Sasaki) (Hemiptera: Aphididae) di akar padi

2020 ◽  
Vol 16 (3) ◽  
pp. 180
Author(s):  
Purnama Hidayat ◽  
Harleni Harleni ◽  
Yani Maharani ◽  
Hermanu Triwidodo
Keyword(s):  
Growth Rate ◽  
Life Cycle ◽  
Doubling Time ◽  
Demographic Variable ◽  
Aphid Species ◽  
Intrinsic Growth Rate ◽  
Statistical Parameters ◽  
Rice Plants ◽  
Rice Roots ◽  
Important Pest

<p><em>Rhopalosiphum </em><em>rufiabdominale</em> (Sasaki) and <em>Tetraneura nigriabdominalis</em> (Sasaki) are aphid species found in the roots of rice plants. Information about the host range and biology of <em>R. </em><em>rufiabdominale</em> is relatively known than <em>T. nigriabdominalis</em>. This study aims to determine the biology and demographic statistics of <em>R. </em><em>rufiabdominale</em> and <em>T. nigriabdominalis</em> in the roots of rice plants. The aphids obtained from lowland rice roots in Leuwiliang, Bogor Regency were maintained and reared in Ciherang variety rice roots in the laboratory. Each individual of the 1st instar aphid nymph in the same cohort was infested into the roots of rice in 60 plastic containers for biological observations and statistical demographic variable data collection. Survivorship (l<sub>x</sub>), fecundity (m<sub>x</sub>), and the average number of nymphs born by adult every day at age (x) are used to calculate demographic statistical parameters. The results showed that the two species of the aphids have 4 nymph instars. Life cycle and longevity of <em>R. </em><em>rufiabdominale</em> were 4.98 days and 15.94 days with fecundity of 67.44 respectively, whereas the life cycle and longevity of <em>T. nigriabdominalis </em>were 5.25 days and 18.11 days with fecundity of 11.11 respectively. <em>R. </em><em>rufiabdominale</em> aphids have an intrinsic growth rate (r) of 0.46 days and a doubling time (DT) of 1.50 days, whereas <em>T. nigriabdominalis</em> has an intrinsic growth rate of 0.14 days and a doubling time of 4.99 days. The results of this study indicate that although the life cycle lengths of the two species are almost the same, the population of <em>R. </em><em>rufiabdominale</em> develops 3.5 times faster than <em>T. nigriabdominalis</em> and therefore <em>R. </em><em>rufiabdominale</em> has the potential to become an more important pest in rice plants.</p>

scholarly journals The ameliorative effect of selenium on Azolla caroliniana grown under UV-B stress

2015 ◽  
Vol 95 (1) ◽  
pp. 20-26 ◽  
Author(s):  
E.M. Mostafa ◽  
A.M.A. Hassan
Keyword(s):  
Growth Rate ◽  
Protein Content ◽  
Doubling Time ◽  
The Other ◽  
Total Glutathione ◽  
Nutrient Media ◽  
Relative Growth ◽  
Other Hand ◽  
Ameliorative Effect ◽  
Glutathione Redox

Exposure ofAzollaplants to UV-B radiation for 6 h resulted in a decrease in biomass and relative growth rate (RGR), which coincided with an increase in doubling time (DT) as compared with the control. Also, the protein content decreased. On the other hand, hydrogen peroxyde (H2O2) and malondialdehyde (MDA) accumulated significantly in UV-treatedAzollaplants. Conversely, the addition of selenium (Se) at 1 ppm resulted in a significant increase in biomass and protein content of untreated and UV-treatedAzollaplants, and a significant reduction in both H2O2and MDA. Moreover, the addition of Se to UV-treated and untreatedAzollaplants resulted in a significant increase in total ascorbate and total glutathione (GSH) contents compared with the control and UV-stressedAzollaplants. Also, glutathione redox potential (GSH/TG) increased significantly in UV-treatedAzollaplants in the presence of Se. There also was a significant increase (38%) in ascorbate peroxidase (APX) activity in UV-treated plants compared with the control. APX activity in the presence of Se did not change significantly compared with the control. Glutathione reductase (GR) activity increased significantly in UV-treatedAzolla, while glutathione peroxidase (GSH-PX) activity did not. On the other hand, both GSH-PX and GR activity in untreated and UV-treatedAzollaplants were significantly enhanced by the application of Se to the nutrient media at a concentration of 1 ppm. Therefore, we can conclude that Se protectsAzollaplants from UV-B stress.

scholarly journals Analysis of development of basic characteristics of the dairy industry in the Czech Republic

2005 ◽  
Vol 53 (6) ◽  
pp. 93-100
Author(s):  
Renata Kučerová
Keyword(s):  
Growth Rate ◽  
Czech Republic ◽  
Life Cycle ◽  
Dairy Industry ◽  
Raw Milk ◽  
The European Union ◽  
Agricultural Producers ◽  
The Czech Republic ◽  
Market Growth ◽  
Basic Characteristics

The paper deals with the analysis of changes in the development of basic characteristics of the dairy industry in the Czech Republic, which cohere with the integration of the Czech Republic into the European Union. The attention is paid on size of the market, growth rate, life cycle, development of prices and development of foreign trade. The total domestic consumption reached 2111.1 million litres in 2004. The industry is in the maturity. The excess of supply exists in the industry; the growth rate is low, under 5% per year. The integration of the Czech Republic into the EU didn’t bring about changes in the development of basic characteristics – size of the market, growth rate, and life cycle. The volume of production changed. The total volume of purchase of raw milk for production went down by 1.4% to the value in 2000. And all prices in the product vertical – milk and milk products (prices of agricultural producers, production prices and consumer’s prices) rose.The paper is a part of solution of the research plan of the FBE MUAF in Brno, No. MSM 6215648904.

scholarly journals Qualitative Analysis of the Effect of Weeds Removal in Paddy Ecosystems in Fallow Season

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Leru Zhou ◽  
Zhigang Liu ◽  
Tiejun Zhou
Keyword(s):  
Growth Rate ◽  
Equilibrium State ◽  
Excretion Rate ◽  
Critical Value ◽  
Inorganic Fertilizer ◽  
Paddy Fields ◽  
Asymptotically Stable ◽  
Intrinsic Growth Rate ◽  
Stable Conditions ◽  
Coexistence Equilibrium

In the paper, we introduce a differential equations model of paddy ecosystems in the fallow season to study the effect of weeds removal from the paddy fields. We found that there is an unstable equilibrium of the extinction of weeds and herbivores in the system. When the intensity of weeds removal meets certain conditions and the intrinsic growth rate of herbivores is higher than their excretion rate, there is a coexistence equilibrium state in the system. By linearizing the system and using the Routh–Hurwitz criterion, we obtained the local asymptotically stable conditions of the coexistence equilibrium state. The critical value formula of the Hopf bifurcation is presented too. The model demonstrates that weeds removal from paddy fields could largely reduce the weeds biomass in the equilibrium state, but it also decreases the herbivore biomass, which probably reduces the content of inorganic fertilizer in the soil. We found a particular intensity of weeds removal that could result in the minimum content of inorganic fertilizer, suggesting weeds removal should be kept away from this intensity.

scholarly journals Exploring Data Mining Research in West Africa: A Bibliometric Analysis

2020 ◽  
Vol 9 (2) ◽  
Author(s):  
Oladosu O. Oladimeji ◽  
Olayanju O. Oladimeji
Keyword(s):  
Data Mining ◽  
Growth Rate ◽  
West Africa ◽  
Relative Growth Rate ◽  
Bibliometric Analysis ◽  
Doubling Time ◽  
Research Output ◽  
Relative Growth

This research paper's main objective is to quantify and analyze the research output of data mining in West Africa, including (1) growth in publications as measured by the Relative Growth Rate (RGR) and Doubling Time (Dt), (2) productivity and quantification of research output for different institutions of the region (West Africa).

Species of Aphis inhabiting European Oenothera: their biology, morphology and systematics (Hemiptera: Aphididae)

2008 ◽  
Vol 3 (3) ◽  
pp. 307-319 ◽  
Author(s):  
Rimantas Rakauskas
Keyword(s):  
Life Cycle ◽  
Host Plant ◽  
Entire Range ◽  
Morphological Character ◽  
Original Data ◽  
Aphid Species ◽  
Life Cycles ◽  
European Species ◽  
Current State ◽  
The World

AbstractInformation on the Aphis species that feed on evening primroses (Oenothera spp.) has been summarized in the catalogue of the aphid species inhabiting herbaceous plants of the world (Blackman &amp; Eastop, 2006). Recent descriptions of the European species, A. holoenotherae (Rakauskas, 2007), that appeared to be a sibling of the American A. oenotherae, demonstrated the need of reexamining the current state of knowledge of the Aphis species inhabiting evening primroses in Europe. The present study, based on published original data, revealed nine aphid species of the genus Aphis which are capable of living on Oenothera plants in Europe. Only two of them are really dependent on Oenothera species during their life cycle: A. oenotherae Oestlund and A. holoenotherae Rakauskas. They have different life cycles and host plant spectrum, although they are very close in their morphology. Processus terminalis length appeared to be the most reliable morphological character in distinguishing between apterous and alate viviparous females, and males of A. oenotherae and A. holoenotherae at the present time. A. grossulariae is not a typical Oenothera-feeder in Europe, occurring on evening primroses only by chance. Other Aphis species (epilobiaria, fabae, sambuci, praeterita, frangulae, nasturtii), are opportunistic inhabitants of Oenothera plants. Information about host specificity and morphology of the Oenothera-inhabiting European Aphis species is summarized, and a key for the entire range of species found living on European Oenothera is provided.

Authorship Pattern and Collaboration Coefficient of Library Professional’s Competency on Research Publications During 1999-2018: A Scientometric Analysis

2019 ◽  
Vol 9 (1) ◽  
pp. 85-89
Author(s):  
Nutan Gaud ◽  
M. P. Singh ◽  
Bhoopendra Singh
Keyword(s):  
Growth Rate ◽  
Doubling Time ◽  
The United States ◽  
Annual Growth ◽  
Scientometric Analysis ◽  
Annual Growth Rate ◽  
Authorship Pattern ◽  
Relative Growth ◽  
Compound Annual Growth Rate ◽  
Scopus Database

The present study aims to analysis authorship pattern and collaboration coefficient of library professional’s competency publications research from 1999-2018. The data has been downloaded by Scopus database. A total number of published articles during the period of study was 433 in the particular database on the topic of ‘professional’s competency’. The study examine various scientometric parameter such as authorship pattern, year wise distribution of publication, determine the annual growth rate and compound annual growth rate of publication, relative growth rate and doubling time of publication and so many. After the analysis, it is found that the highest 11.78% of an article published in the year 2015. The highest growth rate in 2000 and the lowest in 1999. The United States published highest 174 article and secured first place in top five countries wish distribution of the publication. Majority of the article is published by single authors is 171 articles during the period of study.

scholarly journals Using the intrinsic growth rate of the mosquito population improves spatio-temporal dengue risk estimation

Acta Tropica ◽  
2020 ◽  
Vol 208 ◽  
pp. 105519
Author(s):  
Luigi Sedda ◽  
Benjamín M. Taylor ◽  
Alvaro E. Eiras ◽  
João Trindade Marques ◽  
Rod J. Dillon
Keyword(s):  
Growth Rate ◽  
Risk Estimation ◽  
Mosquito Population ◽  
Intrinsic Growth Rate ◽  
Spatio Temporal

Fate and Transformation of CuO Nanoparticles in the Soil–Rice System during the Life Cycle of Rice Plants

2017 ◽  
Vol 51 (9) ◽  
pp. 4907-4917 ◽  
Author(s):  
Cheng Peng ◽  
Chen Xu ◽  
Qinglin Liu ◽  
Lijuan Sun ◽  
Yongming Luo ◽  
...  
Keyword(s):  
Life Cycle ◽  
Cuo Nanoparticles ◽  
Rice Plants

Determining Whether Tumor Volume Doubling Time and Growth Rate Can Predict Malignancy After Delayed Diagnostic Surgery of Follicular Neoplasm

Thyroid ◽  
2019 ◽  
Vol 29 (10) ◽  
pp. 1418-1424 ◽  
Author(s):  
Mijin Kim ◽  
Sae Rom Chung ◽  
Min Ji Jeon ◽  
Minkyu Han ◽  
Jeong Hyun Lee ◽  
...  
Keyword(s):  
Growth Rate ◽  
Doubling Time ◽  
Tumor Volume ◽  
Follicular Neoplasm ◽  
Tumor Volume Doubling Time ◽  
Volume Doubling Time ◽  
Volume Doubling
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