scholarly journals Seasonal impacts on leaf attributes of several tree species growing in three diverse ecosystems of south-eastern Australia

2004 ◽  
Vol 52 (3) ◽  
pp. 293 ◽  
Author(s):  
Skye McPherson ◽  
Derek Eamus ◽  
Brad R. Murray

Patterns of leaf attributes were examined for six woody species growing in a eucalypt woodland, a mangrove, or a heathland in coastal New South Wales, Australia, during winter and summer. It was found that the rate of assimilation per unit leaf dry mass (Amass) of the mangrove species was largest, woodland species exhibiting an intermediate rate and heathland species the smallest values of Amass. Mean habitat Amass did not change from winter to summer in the woodland or mangrove species but increased significantly in the heathland species. Average specific leaf area (SLA) was largest for the mangrove species and smallest for the heathland species, with woodland species showing intermediate values. SLA of all species within a habitat did not change from winter to summer. Mean foliar nitrogen (Nmass) of the mangrove species was highest, intermediate for woodland species and lowest for heathland species. Nmass was significantly related to Amass in both summer and winter and the individual slopes for this relationship in the summer and winter differed. In contrast, a common slope was fitted to the relationship between SLA and Amass for the two seasons. A common slope between seasons was also shown for the relationship between SLA and Nmass. There was no significant difference in slope elevation between summer and winter for the SLA v. Nmass relationship. Trends within relationships among leaf attributes were the same as those found for a wide range of plant species worldwide, but the absolute values were lower than those found elsewhere. Therefore, the 'global relationships' in terms of trends (positive or negative) that have been determined overseas apply in Australia but the elevation of the slope and the magnitude of the slope are reduced (Amass v. Nmass) or increased (Amass v. SLA and Nmass v. SLA) compared with global trends.

2005 ◽  
Vol 53 (1) ◽  
pp. 33 ◽  
Author(s):  
Emma K. Gras ◽  
Jennifer Read ◽  
Chantal T. Mach ◽  
Gordon D. Sanson ◽  
Fiona J. Clissold

Eucalyptus species often show marked differences in morphology and ecophysiology between adult and juvenile leaves. Given these differences, it was hypothesised that juvenile and adult leaves would present different levels of resources to a herbivore, and potentially different levels of putative anti-herbivore defences. This hypothesis was tested in some eucalypts growing in native forest in south-eastern Australia. There were no significant differences in levels of water, protein or carbohydrates (per unit dry weight) between mature adult and juvenile leaves. No difference was recorded in concentration of total phenolics between leaf forms, but more protein was precipitated (an estimate of tannin activity) in extracts from juvenile leaves. Cyanogenic glycosides were absent from mature leaves, but present in young leaves of both leaf forms in E. polyanthemos. No significant difference in concentration of any terpene was recorded between adult and juvenile leaves in E. nitens and E. regnans. Specific leaf area was lower in adult leaves, and fibre concentration was higher in adult leaves of some species, suggesting that resources in the adult leaf may be less accessible to a herbivore. However, there was no difference in leaf toughness between leaf forms, even though toughness per unit leaf thickness was higher in juvenile leaves. Hence, no major trends in resource concentration were apparent between the leaf forms, and of the defences investigated, only tannin activity varied significantly between the leaf forms.


1949 ◽  
Vol 39 (3) ◽  
pp. 254-258 ◽  
Author(s):  
E. G. Hallsworth

A study of the published data for feeding-stuff composition, digestibility and starch equivalent has shown that a linear relationship exists between the crude-fibre content and digestibility, and between crude-fibre content and starch equivalent.No significant difference was found between the regression coefficients for crude fibre and digestibility for sheep and cattle, but the coefficients for horses and pigs were notably larger, and significantly so for pigs.For pasture herbage the relationship between protein and starch equivalent was found to be merely a reflexion of the fibre content, and the regression coefficient between them became non-significant when crude fibre was included in the regression analysis. An equation has been obtained connecting crude fibre with starch equivalent, which is valid over a wide range of pasture species and fibre contents.


2011 ◽  
Vol 61 (10) ◽  
pp. 2379-2383 ◽  
Author(s):  
Ana Paula B. Moreira ◽  
Nei Pereira ◽  
Fabiano L. Thompson

The aim of this study was to evaluate the utility of a real-time PCR platform to estimate the DNA G+C content (mol%) and DNA–DNA hybridization (DDH) values in the genus Vibrio. In total, nine vibrio strains were used to determine the relationship between genomic DNA G+C content and T m (°C). The T m and HPLC datasets fit a linear regression curve with a significant correlation coefficient, corroborating that this methodology has a high correlation with the standard methodology based on HPLC (R2 = 0.94). Analysis of 31 pairs of vibrios provided a wide range of ΔT m values, varying between 0.72 and 12.5 °C. Pairs corresponding to strains of the same species or strains from sister species showed the lowest ΔT m values. For instance, the ΔT m of the sister species Vibrio harveyi LMG 4044T and Vibrio campbellii LMG 11216T was 5.2 °C, whereas the ΔT m of Vibrio coralliilyticus LMG 20984T and Vibrio neptunius LMG 20536T was 8.75 °C. The mean ΔT m values corresponding to pairs of strains with DDH values lower than 60 % or higher than 80 % were, respectively, 8.29 and 2.21 °C (significant difference, P<0.01). The high correlation between DDH values obtained in previous studies and the ΔT m values (R2 = 0.7344) indicates that the fluorimetric methodology is a reliable alternative for the estimation of both DNA G+C content and ΔT m in vibrios. We suggest that strains of the same Vibrio species will have less than 4 °C ΔT m. The use of a real-time PCR platform represents a valuable alternative for the development of the taxonomy of vibrios.


Weed Science ◽  
2007 ◽  
Vol 55 (2) ◽  
pp. 152-156 ◽  
Author(s):  
Hanan Eizenberg ◽  
Tal Lande ◽  
Gay Achdari ◽  
Asia Roichman ◽  
Joseph Hershenhorn

Broomrapes (Orobanche spp.) are chlorophyll-lacking root parasites of many dicotyledonous species that cause severe damage to vegetables and field crops worldwide. Egyptian broomrape is common throughout Israel, where it parasitizes a wide range of crops. The main damage caused by this parasite is to processing tomatoes. The objectives of this study were to determine (1) the relationship between the parasitism process on tomato roots and Egyptian broomrape seed depth, and (2) the effect of herbicide application on Egyptian broomrape control at depths of 0 to 30 cm. The study was conducted in controlled conditions in 25-L pots containing soil that was artificially infested with Egyptian broomrape seeds. Seeds (1-cm layer) were infested at soil surface and at depths of 6, 12, 18, 24, and 30 cm. Sulfosulfuron was applied PRE to Egyptian broomrape shoots, 14 and 42 d after tomato planting. Egyptian broomrape emergence was highly correlated to the depth of the seed infestation: the deeper the seeds were buried, the more pronounced the delay in Egyptian broomrape emergence. A four-parameter sigmoid equation was found that describes the relationship between Egyptian broomrape parasitism and seed depth. No Egyptian broomrape shoots were observed aboveground when sulfosulfuron was applied on tomato foliage. However, live and dead attachments were observed at different levels in all seed-depth treatments. No significant difference in the efficacies of sulfosulfuron at rates of 37.5 and 75 ai ha−1 was observed at depths of 6, 12, and 18 cm. The best control was obtained at a depth of 6 cm at both sulfosulfuron rates. At depths of 24 and 30 cm, no broomrape control was achieved at 37.5 ai g ha−1 sulfosulfuron, and only low control efficacy was obtained at 75 ai g ha−1.


Healthcare ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 518
Author(s):  
Amir Karami ◽  
Alicia A. Dahl ◽  
George Shaw ◽  
Sruthi Puthan Valappil ◽  
Gabrielle Turner-McGrievy ◽  
...  

The relationship between political affiliations and diet-related discussions on social media has not been studied on a population level. This study used a cost- and -time effective framework to leverage, aggregate, and analyze data from social media. This paper enhances our understanding of diet-related discussions with respect to political orientations in U.S. states. This mixed methods study used computational methods to collect tweets containing “diet” or “#diet” shared in a year, identified tweets posted by U.S. Twitter users, disclosed topics of tweets, and compared democratic, republican, and swing states based on the weight of topics. A qualitative method was employed to code topics. We found 32 unique topics extracted from more than 800,000 tweets, including a wide range of themes, such as diet types and chronic conditions. Based on the comparative analysis of the topic weights, our results revealed a significant difference between democratic, republican, and swing states. The largest difference was detected between swing and democratic states, and the smallest difference was identified between swing and republican states. Our study provides initial insight on the association of potential political leanings with health (e.g., dietary behaviors). Our results show diet discussions differ depending on the political orientation of the state in which Twitter users reside. Understanding the correlation of dietary preferences based on political orientation can help develop targeted and effective health promotion, communication, and policymaking strategies.


2000 ◽  
Vol 39 (01) ◽  
pp. 10-15 ◽  
Author(s):  
S. P. Müller ◽  
Ch. Reiners ◽  
A. Bockisch ◽  
Katja Brandt-Mainz

Summary Aim: Tumor scintigraphy with 201-TICI is an established diagnostic method in the follow-up of differentiated thyroid cancer. We investigated the relationship between thyroglobulin (Tg) level and tumor detectability. Subject and methods: We analyzed the scans of 122 patients (66 patients with proven tumor). The patient population was divided into groups with Tg above (N = 33) and below (N = 33) 5 ng/ml under TSH suppression or above (N = 33) and below (N = 33) 50 ng/ml under TSH stimulation. Tumor detectability was compared by ROC-analysis (True-Positive-Fraction test, specificity 90%). Results: There was no significant difference (sensitivity 75% versus 64%; p = 0.55) for patients above and below 5 ng/ml under TSH suppression and a just significant difference (sensitivity 80% versus 58%; p = 0.04) for patients above and below 50 ng/ml under TSH stimulation. In 18 patients from our sample with tumor, Tg under TSH suppression was negative, but 201-TICI-scan was able to detect tumor in 12 patients. Conclusion: Our results demonstrate only a moderate dependence of tumor detectability on Tg level, probably without significant clinical relevance. Even in patients with slight Tg elevation 201-TICI scintigraphy is justified.


2008 ◽  
pp. 61-76
Author(s):  
A. Porshakov ◽  
A. Ponomarenko

The role of monetary factor in generating inflationary processes in Russia has stimulated various debates in social and scientific circles for a relatively long time. The authors show that identification of the specificity of relationship between money and inflation requires a complex approach based on statistical modeling and involving a wide range of indicators relevant for the price changes in the economy. As a result a model of inflation for Russia implying the decomposition of inflation dynamics into demand-side and supply-side factors is suggested. The main conclusion drawn is that during the recent years the volume of inflationary pressures in the Russian economy has been determined by the deviation of money supply from money demand, rather than by money supply alone. At the same time, monetary factor has a long-run spread over time impact on inflation.


Author(s):  
Ma. Dulce C. Guillena

Gonado-somatic index and fecundity are tools for measuring the sexual maturity and ability of animals to reproduce.  This study investigates the reproduction of Trichiurus lepturus. Specifically, this aimed to determine the sex ratio, the GSI, the relationship between fecundity and total length, fecundity and total weight, fecundity and ovary weight. The Descriptive Method of research was used.  Percentage and chi-square was utilized in determining the percentage of occurrence and sex ratio respectively.   Pearson r Product Moment Coefficient of Correlation was used to determine the relationships of the parameters. The study revealed that females outnumbered males and the sex ratio for different month showed significant difference.  Spawning season was observed to occur in November and December as revealed in its GSI values and it synchronized with the full and new moon phases.  Fecundity is positively correlated with body weight, body size, and ovary weight where ovary weight is observed to be the best index for fecundity.  The results of this study could be used further for formal stock assessment of cutlassfish fishery.


Agrometeoros ◽  
2018 ◽  
Vol 26 (1) ◽  
Author(s):  
Ronaldo Matzenauer ◽  
Bernadete Radin ◽  
Alberto Cargnelutti Filho

O objetivo deste trabalho foi avaliar a relação entre o fenômeno El Niño Oscilação Sul - ENOS e o rendimento de grãos de soja e de milho no Rio Grande do Sul e verificar a hipótese de que os eventos El Niño são favoráveis e os eventos La Niña são prejudiciais ao rendimento de grãos das culturas. Foram utilizados dados de rendimento de grãos dos anos agrícolas de 1974/75 a 2016/17, e relacionados com as ocorrências de eventos ENOS. Foram analisados os dados de rendimento observados na colheita e os dados estimados com a remoção da tendência tecnológica. Os resultados mostraram que não houve diferença significativa do rendimento médio de grãos de soja e de milho na comparação entre os eventos ENOS. Palavras-chave: El Niño, La Niña, safras agrícolas. Abstract – The objective of this work was to evaluate the relationship between the El Niño Southern Oscillation (ENSO) phenomenon with the grain yield of soybean and maize in Rio Grande do Sul state, Brazil and to verify the hypothesis that the El Niño events are favorable and the La Niña events are harmful to the culture’s grain yields. Were used data from the agricultural years of 1974/75 to 2016/17, and related to the occurrence of ENOS events. We analyzed income data observed at harvest and estimated data with technological tendency was removed. The results showed that there was no significant difference in the average yield of soybeans and corn in the comparison between events.


2019 ◽  
Author(s):  
Siddharth Garg

Objective: The aim of this paper was to examine the relationship between income, subjective wellbeing, and culture among people from a higher socio-economic class across the world. Rationale: Ed Diener proposed the law of diminishing marginal utility as an explanation for differences in subjective wellbeing among different income groups across different countries (Diener, Ng, &amp; Tov, Balance in life and declining marginal utility of diverse resources, 2009). Thus, people with higher incomes would experience less subjective wellbeing due to income, and culture should emerge as a significant predictor. Method: Data from this study came from another study (https://siddharthgargblog.wordpress.com/2019/07/14/love-for-money/). I used an online survey to collect data on annual income in US dollars, subjective wellbeing (WHO-5), and country of residence (Indicator of Culture). 96 responses (Indians = 24, Foreigners = 72) were entered in IBM SPSS and a regression analysis was conducted. The raw dataset used in this study can be found at https://doi.org/10.6084/m9.figshare.8869040.v1Results: ANOVA showed a significant difference (p &lt; 0.05) between Indians and foreigners on levels of subjective wellbeing. Linear regression shows the regression coefficient of culture to be significant (Beta = -.254, p = .014) but the regression coefficient of income was not found to be significant. The overall model was found to explain 8.2% of the variance in wellbeing.Conclusion: The sample of this study is too small to make any kind of generalization; it does lend a little bit of support to the idea of diminishing marginal utility of income on subjective wellbeing and provides a rationale for further research.


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