3,710,047 research outputs found

    Radial Growth Rate Increases in Naturally Occurring Ponderosa Pine Trees: A Late-20th Century CO2 Fertilization Effect?

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    The primary objective of this study was to determine if gradually increasing levels of atmospheric CO2, as opposed to ‘step’ increases commonly employed in controlled studies, have a positive impact on radial growth rates of ponderosa pine (Pinus ponderosa) in natural environments, and to determine the spatial extent and variability of this growth enhancement. We developed a series of tree-ring chronologies from minimally disturbed sites across a spectrum of environmental conditions. A series of difference of means tests were used to compare radial growth post-1950, when the impacts of rising atmospheric CO2 are best expressed, with that pre-1950. Spearman’s correlation was used to relate site stress to growth-rate changes. Significant increases in radial growth rates occurred post-1950, especially during drought years, with the greatest increases generally found at the most water-limited sites. Site harshness is positively related to enhanced radial growth rates. Atmospheric CO2 fertilization is probably operative, having a positive effect on radial growth rates of ponderosa pine through increasing water-use efficiency. A CO2-driven growth enhancement may affect ponderosa pine growing under both natural and controlled conditions

    Uniform growth rate

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    In an evolutionary system in which the rules of mutation are local in nature, the number of possible outcomes after mm mutations is an exponential function of mm but with a rate that depends only on the set of rules and not the size of the original object. We apply this principle to find a uniform upper bound for the growth rate of certain groups including the mapping class group. We also find a uniform upper bound for the growth rate of the number of homotopy classes of triangulations of an oriented surface that can be obtained from a given triangulation using mm diagonal flips.Comment: 13 pages, 5 figures, minor revisions, final version appears in Proc. Amer. Math. So

    Growth Rate Of Blood Cockle (Anadara Granosa) Spat In Intertidal Zone Panipahan Rokan Hilir District Riau Province

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    This research was conducted in November 2015 to January 2016 in Coastal Panipahan Rokan Hilir Riau Province, aimed to compare the growth rate of blood cockle spat (A. granosa) on the three different part of intertidal zone. The method used in this study is an experimental method by using a completely randomized design (CRD) of the factors with 3 levels of treatment, each treatment using 3 replications. The treatments used in the maintenance of blood clam spat that is treatment IBA (upper intertidal zone), treatment IBT (middle intertidal zone), and treatment IBB (lower intertidal zone). The fence netting used measuring 50 × 50 cm as many 9 units are arranged randomly. Blood cockle spat are stocked as many as 100 individuals / fence netting. The results showed that the average rate of growth of the blood cockle spat indicate that lower intertidal zone to produce a faster growth rate than the middle intertidal zone and upper intertidal zone

    Growth And Survival Rate Of Western White Prawns (Litopaneaus Vannamei) On Different Salinity

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    The research was conducted for 30 days from 23 March to 22 April 2015 which was held at the Great Hall Brackishwater Aquaculture Development Jepara, Central Java Province. The aim of this research to determine the different salinity for growth and survival rate of Western white prawns (Litopenaeus vannamei). The method used is the experimental method with completely randomized design (CRD) of the factor with 3 levels a treatment. The treatment was applied, namely P1 of salinity 15 ppt, P2 of salinity 20 ppt, P3 of salinity 25 pptThe best result showed that salinity 15 ppt. Total absolute body weight, absolute body length, daily growth rate and survival rate was 2.09 grams, 6.60 cm, 0.07 grams/day and 94.7 % respectively. Water quality parameters were recorded namely a temperature is 29.1-31.6 oC, pH 7.9-8.1 and dissolved oxygen 3.84- 4.97 ppm

    Growth And Survival Rate Of Giant Prawns (Macrobrachium Rosenbergii De Man) On Different Stocking Density

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    The research was conducted for 30 days from september to october 2014 which was held at the Great Hall of Freshwater Aquaculture Sukabumi, West Java Province. The aim of this research was to determine the different stocking densities for growth and survival rate of Giant prawns (Macrobrachium rosenbergii De Man). The method used is the experimental method with completely randomized design (CRD) of the factor with 3 levels of treatment. The treatment were applied, namely P1 of 40 tail/m2, P2 of 60 tail/m2, P3 of 80 tail/m2.The best results showed that stocking density of40 tail/m2. Total absolute body weight, absolute body length, daily growth rate and survival rate was 5,5 grams, 2,65 cm, 2,25 %/day and 92,5 % respectively.Water quality parameters were recorded namely temperature is 24-26º C, pH 6-7,5 and dissolved oxygen (DO) from 4,3 to 4,8 ppm / l

    Growth rate for beta-expansions

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    Let β>1\beta>1 and let m>\be be an integer. Each x\in I_\be:=[0,\frac{m-1}{\beta-1}] can be represented in the form x=∑k=1∞ϵkβ−k, x=\sum_{k=1}^\infty \epsilon_k\beta^{-k}, where ϵk∈{0,1,...,m−1}\epsilon_k\in\{0,1,...,m-1\} for all kk (a β\beta-expansion of xx). It is known that a.e. x∈Iβx\in I_\beta has a continuum of distinct β\beta-expansions. In this paper we prove that if β\beta is a Pisot number, then for a.e. xx this continuum has one and the same growth rate. We also link this rate to the Lebesgue-generic local dimension for the Bernoulli convolution parametrized by β\beta. When β<1+52\beta<\frac{1+\sqrt5}2, we show that the set of β\beta-expansions grows exponentially for every internal xx.Comment: 21 pages, 2 figure

    Growth And Survival Rate Of Nilem (Osteochilus Hasselti) On Different Stocking Density

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    The research was conducted from April 10 until june 10, 2015. The purpose of this study was to determine the different stocking densities for growth and survival rate of nilem (Osteochilus hasselti). The experiment was designed using Completely Random Design with three treatments and three replications. The treatment were applied, namely P1 of 5 tail/m3, P2 of 10 tail/m3, P3 of 15 tail/m3. The best results showed that stocking density of 10 tail/m3. Total absolute body weight, absolute body length, daily growth rate and survival rate was 4,68 grams, 3,07cm, 1,25 %/day and 93,33 % respectively. Water quality parameters were recorded namely temperature is 26–290 C, pH 6-7 and dissolved oxygen (DO) from 6,2 to 6,7 ppm/l
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