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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
491

Assessing Sow Preference for Scratching Enrichment and Effectiveness in Farrowing Crates

Rebecca Kristine Smith (7480697) 17 October 2019 (has links)
<p>Effective enrichments for farm animals are increasingly important to address public concerns about farm animal welfare and improve the welfare of the animals we raise. The public’s concern has increased in recent years as the management and care that farmers give their animals has become more apparent to them. Some of the conditions in which animals are kept are emotionally not appealing to the public. One such condition is farrowing crates for sows and piglets. The sows are confined in a small space with no social contact and cannot perform nesting behaviors. Farrowing crates are widely used though, as they allow farmers to handle piglets without fear of sow aggression, meet individual sow nutritional needs, and personalize care. Piglet mortality due to crushing is also decreased with crate use. Sow welfare in farrowing crates can be improved through environmental enrichments. Enrichments improve welfare by increasing species-specific behaviors, creating a more complex environment, reducing abnormal behaviors, and increasing an animal’s ability to cope with stressful situations. For pigs, different enrichments have been shown to decrease stereotypies, like sham chewing and bar biting, decrease harmful redirected behavior towards pen mates, like tail biting and belly nosing, increased exploratory behavior, and increase positive affect. Straw has been found to be the best enrichment for pigs because it allows them to perform motivational behaviors such as rooting, foraging, and nest building. It is also complex, manipulatable, destructible, and ingestible, which are important attributes of effective enrichments. Unfortunately, straw cannot be used in farms that have slurry systems, as the straw will fall through the slats into the pit below and cause drainage issues. This includes farrowing crates. There have been a few studies on alternative enrichments for sows in crates, like cloth tassels, but they are not as effective as straw and are rarely used on farm.</p> <p> Most enrichments target pigs’ motivations to forage, root, graze, or build nests. Pigs perform other behaviors and may have other motivations that enrichments have not targeted yet. One such behavior is scratching. In a semi-natural environment, pigs will rub against trees and bushes. In confinement, pigs rub on fences, walls, and even allow people to scratch them with their hands. There have been no recorded studies done on scratching enrichment for pigs. Many studies have been done in the dairy industry exploring rotating brushes. These brushes have been implemented successfully on commercial farms and are used by cows to groom and scratch themselves. A similar device may allow pigs to also satisfy their itch. Our aim is to provide scratching enrichment to sows in farrowing crates. Since there have been no studies recorded on scratching enrichment or scratching in pigs in general, several steps had to take place before addressing the topic for sows in crates. The first project’s aim was to see what materials pigs prefer to scratch on and their willingness to use such an enrichment.</p> <p><a> The first project consisted of 2 experiments. Exp. 1 was a pilot study where 5 different materials on scratch posts were presented to a pen of gestating sows. The scratch posts were constructed from polyvinyl chloride (<b>PVC</b>) pipes, boards, and a gate post. Five different materials were attached to the boards: white, soft, long-bristled brushes (<b>White Brush</b>), red, hard, short-bristled brush (<b>Red Brush</b>), black, short-bristled, astro-turf-like mat (<b>Plastic Mat</b>), colorful coir, hard, short-bristled mat (<b>Fiber Mat</b>), and blue, plastic, large-round-bristled combs (<b>Plastic Combs</b>). The 8 sows received all 5 scratch posts in their pen for a habituation day and then 7 d of testing. During testing, video was continuously recorded from which 2 behaviors were collected; scratching and interacting. Sows scratched the most on Plastic Mat followed by Fiber Mat, Plastic Combs, and Red Brush. The White Brush was scratched on the least. The top 3 preferences were chosen to proceed to Exp. 2.</a></p> <p> Experiment 2 for sow preference was performed on several pens (N=14) of sows and gilts with Plastic Mat, Fiber Mat, and Plastic Combs to narrow the preference down to 2 materials to proceed to the farrowing crates. The experiment was carried out in repetitions. Each repetition tested 4 pens at a time. The scratch posts were modified from Exp. 1 and each material was placed in a pen. Due to material destruction only 2 repetitions were carried out, both ending a little early (N=8). During the first repetition (<b>Rep 1</b>), sows ate and destroyed all the Plastic Combs within 2 d. The Plastic Comb scratch posts were pulled from the study and the second repetition (<b>Rep 2</b>) only had the Plastic Mat and Fiber Mat represented. An observation was made that one of the pens in Rep1 had extra feed on their floor and were not destroying their materials as fast as the other pens. So for Rep 2, more modifications to the scratch posts were made and the sows were given a little extra feed. The scratch posts were still destroyed in Rep 2 proving that the sows’ hunger and motivation to perform oral manipulations overwhelmed scratching behaviors. However, from the data that was collected sows spent more time and more frequently interacted with the Fiber Mat compared to the Plastic Mat. They more frequently and spent more time interacting than scratching with the enrichments but scratched on both enrichments the same amount of time and frequency (Durations: F<sub>1,112.6 </sub>= 13.63, <i>P</i> = 0.0003; Frequencies: F<sub>1,111.9 </sub>= 19.72, <i>P</i> < 0.0001).</p> <p> The plastic and fiber mats were presented to sows in farrowing crates for the second project by default. Sows (N=18) of parities 2 (<b>P2</b>) and 3 (<b>P3</b>) were housed for 25 d and assigned no enrichment (<b>Control</b>) or to a scratch pad treatment of plastic mats (<b>Plastic</b>) or fiber mats (<b>Fiber</b>). All were assessed for lesions, abnormal behaviors, eating and scratching behaviors, and time spent in different postures and behaviors. Scratching bouts occurred in short durations and were intermittent throughout the day. Parity 2 Plastic sows scratched for a longer total duration than P2 and P3 Fiber sows, P3 Plastic sows, and P2 Control sows (F<sub>2,11 </sub>= 11.94,<i> P</i> = 0.002). Parity 2 Plastic sows also displayed scratching bouts more frequently than all except P3 Control sows (F<sub>2,11 </sub>= 18.46, <i>P</i> = 0.0003). There were no body lesion differences between treatments (<i>P</i> > 0.05). Abnormal behaviors (<i>P</i> > 0.05) and proportion of time spent in different postures (F<sub>2,94 </sub>= 0.0003, <i>P</i> = 0.999) did not differ among treatments. </p> In conclusion, if a sow is experiencing hunger while in gestation pens this motivation may be overwhelming any other behavior needs. Scratch posts were destroyed and eaten. In this sort of environment, focusing on an enrichment that meets the need to forage and root would be more successful. Sows still scratched on the posts, so their preference and scratching use was still recorded to an extent to proceed to the experiment in farrowing crates. In farrowing crates, plastic scratch pads may be a suitable enrichment as they increased the natural behavior of scratching and did not increase abnormal behaviors. More research is needed to refine the scratch pad design and identify additional measures needed to examine the suitability of scratch pads as a form of environmental enrichment for sows in farrowing crates. In addition, the behavioral characteristics and sows’ underlying motivation for scratching need to be studied because very little is known about scratching behavior of sows. If sows are motivated to scratch, and scratching helps improve their welfare, then scratching enrichment may be beneficial to sows and farmers.
492

Métodos de seleção genômica aplicados a sorgo biomassa para produção de etanol de segunda geração / Genome wide selection methods applied to high biomass sorghum for the production of second generation ethanol

Oliveira, Amanda Avelar de 03 July 2015 (has links)
As crescentes preocupações com questões ambientais têm despertado interesse global pelo uso de combustíveis alternativos, e o uso da biomassa vegetal surge como uma alternativa viável para a geração de biocombustíveis. Diferentes materiais orgânicos têm sido utilizados, e dentre eles destaca-se o sorgo biomassa (Sorghum bicolor L. Moench). A seleção genômica apresenta grande potencial e pode, em médio prazo, reestruturar os programas de melhoramento de plantas, promovendo maiores ganhos genéticos quando comparada a outros métodos, além de reduzir significativamente o tempo necessário para o desenvolvimento de novas cultivares, através da seleção precoce. Este trabalho teve como objetivo avaliar modelos de seleção genômica e aplicá-los para a predição dos valores genéticos de indivíduos do painel de sorgo biomassa da Embrapa/Milho e Sorgo. Tal painel inclui materiais do banco de germoplasma e materiais utilizados em programas de melhoramento de sorgo dessa instituição, bem como coleções núcleo do CIRAD e ICRISAT, sendo, portanto, subdividido em dois sub-painéis. As 100 linhagens do sub-painel 1 foram avaliadas fenotipicamente por dois anos (2011 e 2012) e as 100 linhagens do sub-painel 2 por um ano (2011), ambas no município de Sete Lagoas-MG, para as seguintes características fenotípicas: tempo até o florescimento, altura de plantas, produção de massa verde e massa seca, proporções de fibra ácida e neutra, celulose, hemicelulose e lignina. Posteriormente, as 200 linhagens integrantes do painel foram genotipadas através da técnica de genotipagem por sequenciamento. A partir desses dados genotípicos e fenotípicos, os modelos de seleção genômica Bayes A, Bayes B, Bayes C&pi;, Bayes Lasso, Bayes Ridge Regression e Random Regression BLUP (RRBLUP) foram ajustados e comparados. As capacidades preditivas obtidas foram elevadas e pouco variaram entre os diversos modelos, variando de 0,61 para o caráter florescimento a 0,85 para a proporção de fibra ácida, quando o modelo RRBLUP foi empregado na análise conjunta dos dois sub-painéis. Por outro lado, a predição cruzada entre sub-painéis resultou em capacidades preditivas substancialmente menores, nunca superiores a 0,66 e em alguns cenários virtualmente iguais a zero, além de apresentar maiores variações entre os modelos ajustados. Simulações do uso de subconjuntos dos marcadores moleculares são apresentadas e indicam possibilidades de obtenção de capacidades preditivas mais elevadas. Análises de enriquecimento funcional realizadas a partir dos efeitos preditos dos marcadores sugeriram associações interessantes, as quais devem ser investigadas com maiores detalhes em estudos futuros, com potencial de elucidação da arquitetura genética dos caracteres quantitativos. / Increased concerns about environmental issues have aroused global interest in the use of alternative fuels, and the use of plant biomass emerges as a viable alternative for the generation of biofuels. Different organic materials have been used, including high biomass sorghum (Sorghum bicolor L. Moench). Genomic selection has great potential and could, in the medium term, restructure plant breeding programs, promoting greater genetic gains when compared to other methods and significantly reducing the time required for the development of new cultivars through early selection. This work aimed at evaluating models of genomic selection and applying them to the prediction of breeding values for a panel of high biomass sorghum genotypes of Embrapa / Milho e Sorgo. This panel includes materials from the gene bank and materials used in sorghum breeding programs of this institution, as well as core collections from CIRAD and ICRISAT, and is therefore divided into two sub-panels. The 100 lines of sub-panel 1 were evaluated phenotypically for two years (2011 and 2012) and the 100 lines of sub-panel 2 for one year (2011), both in the city of Sete Lagoas, Minas Gerais, for the following phenotypic traits: days to flowering, plant height, fresh and dry matter yield and fiber, cellulose, hemicellulose and lignin proportions. Subsequently, the 200 lines were genotyped by via the genotyping by sequencing technique. From these genotypic and phenotypic data, genomic selection models Bayes A, Bayes B, Bayes C&pi;, Bayes Lasso, Bayes Ridge Regression and Random Regression BLUP (RRBLUP) were fitted and compared. The predictive capabilities obtained were high and varied little between the different models, ranging from 0.61 for days to flowering to 0.85 for acid fiber, when the RRBLUP model was used on the combined analysis of the two sub-panels. On the other hand, cross prediction between sub-panels resulted in substantially lower predictive capability, never above 0.66 and in some scenarios virtually equal to zero, with greater variations between the fitted models. Simulations of using subsets of molecular markers are presented and indicate possibilities of achieving higher predictive capabilities. Functional enrichment analyses performed with the marker predicted effects suggested interesting associations, which should be investigated in more detail in future studies, with potential for elucidating the genetic architecture of quantitative traits.
493

Concentration of dairy flavours using pervaporation : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Food Technology at Massey University, Auckland, New Zealand

Overington, Amy Rachael January 2008 (has links)
The food industry could potentially benefit from using pervaporation, a membrane process, to concentrate flavours. This research aimed to investigate its application for concentrating flavours in dairy process streams. Pervaporation experiments were carried out at a range of operating conditions, using hydrophobic membranes. The feed mixtures were either aqueous model solutions of dairy flavour compounds (acids, esters and ketones), complex model mixtures containing flavour compounds plus non-volatile dairy components, or real dairy products. Flavour compound enrichment factors ranged from below one to above 30, with esters and ketones being concentrated more effectively than acids. Thus, the flavours could be partially fractionated based on their chemical structure. The permeation of acids was reduced by approximately 50% when the feed pH was increased to near their p Ka values. For flavour compounds with lower molecular weights than approximately 1 20 g mol- I , permeation was controlled mainly by sorption i n the membrane; for larger compounds it was controlled mainly by diffusion through the membrane. The mass transfer of each flavour compound increased with temperature, following an Arrhenius-like relationship. The activation energy was a function of each compound's heat of sorption, its molecular weight, and the elastic modulus of the membrane. The activation energy was also related to the Arrhenius preexponential factor. Thus, fluxes could be estimated through empirical correlations. The non-volatile feed composition was an important factor influencing the pervaporation performance. Milk protein isolate (4% w/v) or lactose (6% or 1 2% w/v) bound with the flavour compounds in the feed, thus lowering the enrichment of sorption-controlled compounds. Milk fat (up to 38% w/v, in the form of cream ) reduced the enrichment of all the flavour compounds tested. Esters and ketones became unavailable for pervaporation as they partitioned into the fat phase; acids remained mainly in the aqueous phase, but their permeation was reduced because the added cream increased the feed pH. Experiments with real dairy products showed that pervaporation could be used to concentrate diacetylin starter distillate, and to selectively recover short-chain esters from ester cream. Of these two products, starter distillate is the more promising for use as a pervaporation feed stream.
494

Effects of the captive environment and enrichment on the daily activity of European Bison (<em>Bison bonasus</em>)

Godoy, Erika January 2009 (has links)
<p>When breeding wild species in captivity, the animals may gradually become more adapted to captivity and therefore less suited for reintroduction which is the ultimate goal for some species. This study measured the activity budget of European bison (<em>Bison bonasus</em>) in six enclosures in Sweden with the aim to find out how the characteristics of the enclosures – with and without pasture - influenced the activity budget. The results show that there were significant differences in the activity budget, i.e. the activity was higher in the enclosures with pasture than in enclosures with barren ground. However, since barren enclosures were smaller than naturalistic, it was not possible to exclude the effect of size. Judged from observations of bison in the wild, there seems to be a direct correlation between food availability and ranging, indicating that enclosure characteristics affect activity more than size. The bison foraged differently in the two enclosure categories, but the total amount of time spent on feeding did not differ. A feeding enrichment experiment showed to have more positive effects in the barren enclosures than in the naturalistic ones, as the amount of time of inactivity decreased in the former. Since the genetic characteristics of all Swedish bison are very similar, the differences between the two enclosure groups indicate that the animals still have the ability to respond appropriately to improved environmental quality. Hence the next step in the assessment of the suitability of these bison for release would be to study them during an acclimatisation program.</p>
495

Comparison of HEU and LEU neutron spectra in irradiation facilities at the Oregon State TRIGA�� reactor

Schickler, Robert 01 October 2012 (has links)
In 2008, the Oregon State TRIGA�� Reactor (OSTR) was converted from highly-enriched uranium (HEU) fuel lifetime improvement plan (FLIP) fuel to low-enriched uranium (LEU) fuel. This effort was driven and supported by the Department of Energy's (DoE's) Reduced Enrichment for Research and Test Reactors (RERTR) program. The basis behind the RERTR program's ongoing conversion effort is to reduce the nuclear proliferation risk of civilian research and test reactors. The original intent of the HEU FLIP fuel was to provide fuel to research reactors that could be utilized for many years before a necessary refueling cycle. As a research reactor, the OSTR provides irradiation facilities for a variety of applications, such as: activation analysis, fission-track dating, commercial isotope production, neutron radiography, prompt gamma characterization, and many others. In order to accurately perform these research functions, several studies have been conducted on the HEU FLIP fuel core to characterize the neutron spectra in various experimental facilities of the OSTR. As useful as these analyses were, they are no longer valid due to the change in fuel composition and the resulting alteration of core performance characteristics. The purpose of this study is to characterize the neutron spectra in various experimental facilities within the new LEU core so as to provide data that is representative of the OSTR's current state. / Graduation date: 2013
496

Identification of bacterial pathogenic gene classes subject to diversifying selection

Sumir Panji January 2009 (has links)
<p>Availability of genome sequences for numerous bacterial species comprising of different bacterial strains allows elucidation of species and strain specific adaptations that facilitate their survival in widely fluctuating micro-environments and enhance their pathogenic potential. Different bacterial species use different strategies in their pathogenesis and the pathogenic potential of a bacterial species is dependent on its genomic complement of virulence factors. A bacterial virulence factor, within the context of this study, is defined as any endogenous protein product encoded by a gene that aids in the adhesion, invasion, colonization, persistence and pathogenesis of a bacterium within a host. Anecdotal evidence suggests that bacterial virulence genes are undergoing diversifying evolution to counteract the rapid adaptability of its host&rsquo / s immune defences. Genome sequences of pathogenic bacterial species and strains provide unique opportunities to study the action of diversifying selection operating on different classes of bacterial genes.</p>
497

Effects of the captive environment and enrichment on the daily activity of European Bison (Bison bonasus)

Godoy, Erika January 2009 (has links)
When breeding wild species in captivity, the animals may gradually become more adapted to captivity and therefore less suited for reintroduction which is the ultimate goal for some species. This study measured the activity budget of European bison (Bison bonasus) in six enclosures in Sweden with the aim to find out how the characteristics of the enclosures – with and without pasture - influenced the activity budget. The results show that there were significant differences in the activity budget, i.e. the activity was higher in the enclosures with pasture than in enclosures with barren ground. However, since barren enclosures were smaller than naturalistic, it was not possible to exclude the effect of size. Judged from observations of bison in the wild, there seems to be a direct correlation between food availability and ranging, indicating that enclosure characteristics affect activity more than size. The bison foraged differently in the two enclosure categories, but the total amount of time spent on feeding did not differ. A feeding enrichment experiment showed to have more positive effects in the barren enclosures than in the naturalistic ones, as the amount of time of inactivity decreased in the former. Since the genetic characteristics of all Swedish bison are very similar, the differences between the two enclosure groups indicate that the animals still have the ability to respond appropriately to improved environmental quality. Hence the next step in the assessment of the suitability of these bison for release would be to study them during an acclimatisation program.
498

A Hierarchical POD Reduction Method of Finite Element Models with Application to Simulated Mechanical Systems

Björklund, Martin January 2012 (has links)
When simulating mechanical systems the flexibility of the components often has to be taken into account. This is particularly important for simulations when high detailed information is demanded, e.g. to calculate stresses. To this end the Finite Element Method (FEM) is often used. However the models can become very large, containing millions of degrees of freedom. Solving large linear systems are computationally demanding. Therefore ways of reducing the problem is often sought. These reduction does, however, remove much of the details that was to be investigated. In this thesis this problem is addressed by creating a reduction scheme, using Proper Orthogonal Decomposition (POD), that significantly reduces a problem but still captures much of the details. A novel method for enriching regular POD-based model reduction methods with hierarchically determined enrichment POD-modes is developed. The method is proposed and validated in a FEM application towards dynamical simulation. The enriched method is compared against a regular POD reduction technique. An numerical study is made of a model example of linear elasticity in a gearwheel. The numerical study suggests that the error of displacements is around ten times smaller, on average, when using the enriched basis compared to a reference basis of equal dimensionality consisting of only regular POD modes. Also it is shown that local quantities as the von Mises stress in a gearwheel tooth is preserved much better using the enriched basis. An a posteriori error estimate is proposed and proved for the static case, showing that the error is bound. / När man simulerar mekaniska system så måste man ofta ta hänsyn till de ingående komponenternas flexibilitet. Detta är särskilt viktigt då man gör simuleringar med krav på hög detaljkännedom, såsom mätningar av spänningar i kugghjul etc. Till detta ändamål används ofta en Finit Element Metod (FEM). Dock kan modellerna ofta bli väldigt stora, med över en miljon frihetsgrader. Att lösa linjära system av den storleken är beräkningsmässigt krävande. Därför är det naturligt att försöka reducera problemen. Reduktion innebär dock att information försvinner, i synnerhet de detaljer som skulle beräknas. I detta examensarbete så behandlas problemet genom att skapa en ny metod för reducering av stora finita element modeller. Metoden bygger på tidigare kunskap om Proper Orthogonal Decomposition (POD) som ett sätt att reducera modeller. Den nya metoden reducerar finita ellement modeller samtidigt som den bibehåller hög detalj. En ny metod utvecklas för att berika en vanlig POD-baserad modellreduktion med hjälp av hieraktiskt bestämda berikningsmoder. Metoden beskrivs och testas i en dynamisk FEM-applikation av elasticitet i ett kugghjul i 2 dimensioner. Metoden för berikning jämförs numeriskt med en metod som använder vanlig POD-reduktion. Körningar visar att felet i den berikade metoden är omkring 10 gånger mindre, i genomsnitt, jämfört med en vanlig metod. Det visas också att spänningar bevaras på ett mycket bra sätt med den nya berikningsmetoden. Dessutom så formuleras och bevisas ett a posteriori estimat för statiska lastfall, vilket innebär att felet i metoden är bundet.
499

Singing ourselves in

King, Anna-Leah 03 December 2007
In a qualitative study, grade three students in an urban classroom were introduced to Aboriginal children's picture-storybooks followed by "menoh," which are literary response activities. "Menoh" is defined as aesthetics, although, in this study "menoh" activities stem from Anishnabe and Cree cultural ways such as in traditional singing, dance, drumming, art and cooking.<p> The researcher used a reframing as a decolonizing methodology in order to reclaim Aboriginal voice and perspective. Reframing is taking greater control over the way Aboriginal research is structured, analyzed and written. The research data was collected over a period of several months within the classroom where the researcher read aloud and drew Aboriginal and non-Aboriginal listeners into the multi-layers of the stories. Through dialogue and critique, the students discussed the stories in literary circles. They shared meanings about the stories and made connections to their own lives and the lives of others. The stories contained messages about loyalty, respect, responsibility, honesty, humility, trust, and sharing-all those qualities that helped Aboriginal people live the life they did and still do today. Discussion was followed by a variety of "menoh," activities that introduced aesthetic ways of knowing from an Aboriginal perspective.
500

Towards a plant-based method of guiding CO₂ enrichment in greenhouse tomato

Edwards, Diane Roselyn 05 1900 (has links)
Atmospheric CO₂ enrichment is employed by greenhouse tomato growers to increase fruit yields, and CO₂ applications are managed according to atmospheric set points or CO₂ injection rates. These methods do not immediately focus on the targets of CO₂ applications: plant performance and the regulation of plant carbon status. This thesis explores several plant-based approaches that may have potential for use in the management of CO₂ in greenhouse tomato production. Three plant-based approaches to CO₂ management were explored in commercial and experimental tomato greenhouses. These were: (1) simulation modeling, (2) non-destructive analysis of growth and (3) the status of plant carbon reserves. A cost and benefit analysis (c/b) using simulation modeling was carried out using grower-collected greenhouse environment and yield data. Simulation modeling was useful for retrospectively determining c/b of several CO₂ scenarios. The model was effective in predicting long term yields, but not short term yield variations, which limits its application for CO₂ management. Non-destructive measures of growth: stem length and diameter, leaf area and fruit load were found to be too sluggish for daily CO₂ dosing decision-making. Finally, plants growing under CO₂ enrichment can deposit substantial carbon as starch in their leaves. Plant carbon status was evaluated by determining the spatial distribution of leaf starch in the shoot and by following its variation diurnally and after the onset of CO₂ enrichment. As starch is difficult to measure by a grower, leaf mass per unit area (LMA) was also monitored for assessment as a surrogate measure for starch. Leaves in positions 7 to 9 were identified as the most meaningful in the shoot to sample. Diurnal profiles indicated these leaves carryover substantial starch from one day to the next. Monitoring starch at its peak time of accumulation (14 h to 16 h), at sunset and sunrise will indicate how much the peak starch reserves are used overnight. If starch remains high between peak and sunrise the following day, then the plants are in a carbon-surplus state and CO₂ enrichment could be postponed. For upper canopy leaves LMA is substantially influenced by starch and thus is a promising surrogate.

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