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Aerodynamic Performance of Cables with Spiral Protuberances in Strong Winds / 強風下におけるスパイラル突起付きケーブルの空力特性Dao, Minh Thu 25 March 2024 (has links)
京都大学 / 新制・課程博士 / 博士(工学) / 甲第25236号 / 工博第5195号 / 新制||工||1992(附属図書館) / 京都大学大学院工学研究科社会基盤工学専攻 / (主査)教授 八木 知己, 教授 KIM Chul-Woo, 教授 高橋 良和 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DFAM
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In-Vitro In-Vivo Correlation (IVIVC) of Inhaled Products Using Twin Stage ImpingerAl Ayoub, Y., Buzgeia, Asma, Almousawi, Ghadeer, Mazhar, H.R.A., Alzouebi, B., Gopalan, Rajendran C., Assi, Khaled H. 08 December 2021 (has links)
Yes / In vitro dissolution testing as a form of quality control has become a necessity in the pharmaceutical industry.
As such, the need to establish a method that investigates the in vitro dissolution profile of inhaled products
should be taken into account. The prime focus in this study was to examine the in-vitro in-vivo correlation
utilising a modified version of the Twin Stage Impinger and to promote an in vitro dissolution model by
enhancing the Fine Particle Dose (FPD) collection method for dry powder inhalers.
The Twin Impinger was modified by inserting a stainless steel membrane holder disk in the base of the lower
chamber. The design, with optimum drug deposition, was adopted for the dissolution study of budesonide
and salbutamol. Afterwards, the membrane holder system was placed in the bottom of the dissolution vessel.
Phosphate buffer saline (PBS), simulated lung fluid (SLF, Gamble solution) and Phosphate buffer (PB) were
used in the study. The paddle dissolution apparatus, containing 300 mL of the medium, was operated at
75 rpm paddle speed. Samples were collected at defined time intervals and analysed using a validated HPLC
method.
The largest proportion of the budesonide dose was dissolved in PBS compared to PB and SLF. This was due to
the presence of surfactant (0.2% w/v polysorbate), which enhances the wettability and the solubility of the
poorly soluble drug (budesonide). The similarity factors for PBS and PB were 47.6 and 69.7, respectively,
using SLF as a reference, whereas the similarity factor for salbutamol dissolution between PB and SLF was
81.3, suggesting PB is a suitable substitute. Comparison using both the predicted and actual in vivo pharmacokinetics (PK) values of the two drugs, as well as the pattern of their Concentration-Time (c-t) profiles,
showed good similarity, which gave an indication of the validity of this in vitro dissolution method.
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Inhaled dry powder liposomal azithromycin for treatment of chronic lower respiratory tract infectionDallal Bashi, Y.H., Ali, A., Al Ayoub, Y., Assi, Khaled H., Mairs, R., McCarthy, H.O., Tunney, M.M., Kett, V.L. January 1900 (has links)
Yes / A dry powder inhaled liposomal azithromycin formulation was developed for the treatment of chronic respiratory diseases such as cystic fibrosis and bronchiectasis. Key properties including liposome size, charge and encapsulation efficiency powder size, shape, glass transition temperature (Tg), water content and in vitro respiratory deposition were determined. Antimicrobial activity against cystic fibrosis (CF) respiratory pathogens was determined by MIC, MBC and biofilm assays. Cytotoxicity and cellular uptake studies were performed using A549 cells. The average liposome size was 105 nm, charge was 55 mV and encapsulation efficiency was 75 %. The mean powder particle size d[v,50] of 4.54 µm and Mass Median Aerodynamic Diameter (MMAD) was 5.23 µm with a mean Tg of 76˚C and water content of 2.1 %. These excellent physicochemical characteristics were maintained over one year. Liposomal loaded azithromycin demonstrated enhanced activity against P. aeruginosa clinical isolates grown in biofilm. The formulation was rapidly delivered into bacterial cells with > 75 % uptake in 1 h. Rapid uptake into A549 cells via a cholesterol-dependent endocytosis pathway with no cytotoxic effects apparent. These data demonstrate that this formulation could offer benefits over current treatment regimens for people with chronic respiratory infection.
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Genetic analysis of earliness traits in chickpea (<i>Cicer arietinum</i> L.)Kabeta, Yadeta Anbessa 31 July 2007
The latter part of the reproductive growth phase in chickpea (<i>Cicer arietinum</i> L.) often coincides with declining temperature and wet conditions in western Canada, in sharp contrast to many other growing environments. This exacerbates the indeterminate nature of the crop, leading to excessive canopy development, and subsequently resulting in delayed maturity. The objectives of this study were to: i) determine the genetic relationships of short internode, double podding and early flowering traits with earliness of crop maturity; ii) determine the genetic control of major earliness traits in chickpea; iii) assess the patterns of post-flowering dry matter accumulation and partitioning to reproductive parts as related to earliness. <p>The results showed that double podding significantly reduced the number of days taken to maturity, under the conditions where this trait was sufficiently expressed. The best double podding genotypes, i.e. those with 1535% of the podded nodes bearing double pods, were about one week earlier than their single podding counterparts and standard checks. A physiological study revealed that the double podding parental genotype 272-2 partitioned a relatively greater proportion (about 58%) of the total dry matter to pods compared to 4254% in the single podding genotypes. Double podding increased the total number of pods set, and thus the increased demand for assimilates may have precluded further production of stems and leaves, resulting in an earlier transition of reproductive growth to physiological maturity. Days to flowering was positively associated with days to maturity, and partial path analysis revealed that days to flowering contributed to days to maturity indirectly via days to first pod maturity. Days to flowering explained 32% of the variation in days to first pod maturity. However, the short internode trait had an undesirable effect, in that all the short internode segregants were too late to mature. <p>Genetic studies revealed that days to flowering was determined by two major genes plus polygenes in chickpea in the short-season temperate environment of western Canada. The two major genes control over 65% of the phenotypic variation. Also, the additive component of genetic variance was significant for days to first podding, days to first pod maturity, reproductive period, and days to maturity; which is desirable for development of superior inbred cultivars of chickpea. These key phenological traits are interrelated but could be manipulated separately in the breeding process. Additional gain in earliness of crop maturity may be achieved through combined selection for these traits.
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Food safety in fast drying (QDS process®) of dry-cured meat products: high pressure and NaCl-free processing implementationStollewerk, Katharina 20 September 2012 (has links)
With the objective to study food safety aspects of innovative meat technologies and combinations among them, QDS (Quick-dry-slice), NaCl-free processing and high pressure were integrated in the production of two types of sliced dry-cured meat products. Dry fermented sausages (chorizo) were produced at acid (4,8) and low acid (5,2) pH and hurdles such as acidification and smoking were introduced in the production of dry-cured hams. The food safety was evaluated by challenge tests with Listeria monocytogenes and Salmonella. Pathogenic microorganisms could not grow in any of the products, however, their survival was affected by NaCl-free processing, acidification, smoking and pressurization at 600 MPa. High pressure was necessary to assure food safety during storage of the chorizo with the lowest hurdle combination and had an important bactericidal effect in dry-cured hams, which was lower in NaCl-free processing. / Con el objetivo de valorar el impacto que tienen las tecnologías innovadoras en la industria cárnica y combinaciones entre ellas sobre la seguridad alimentaria, el proceso QDS®, el “procesado sin NaCl añadido“ y las altas presiones se integraron en la producción de dos tipos de productos crudo-curados loncheados: chorizo (ácido, pH 4,8, y poco ácido, pH 5,2) y jamón curado (con y sin acidificación y/o ahumado). La seguridad de los productos se avaluó mediante challenge tests con Listeria monocytogenes y Salmonella. Ninguno de los productos permitió el crecimiento de los patógenos pero su evolución se vio afectada por el “procesado sin NaCl añadido“, la acidificación, el ahumado y la presurización a 600 MPa. La presurización fue necesaria para asegurar la seguridad alimentaria durante el almacenaje del chorizo con menos obstáculos y en los jamones curados tuvo un efecto bactericida importante, que fue menor en “procesado sin NaCl añadido“.
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Genetic analysis of earliness traits in chickpea (<i>Cicer arietinum</i> L.)Kabeta, Yadeta Anbessa 31 July 2007 (has links)
The latter part of the reproductive growth phase in chickpea (<i>Cicer arietinum</i> L.) often coincides with declining temperature and wet conditions in western Canada, in sharp contrast to many other growing environments. This exacerbates the indeterminate nature of the crop, leading to excessive canopy development, and subsequently resulting in delayed maturity. The objectives of this study were to: i) determine the genetic relationships of short internode, double podding and early flowering traits with earliness of crop maturity; ii) determine the genetic control of major earliness traits in chickpea; iii) assess the patterns of post-flowering dry matter accumulation and partitioning to reproductive parts as related to earliness. <p>The results showed that double podding significantly reduced the number of days taken to maturity, under the conditions where this trait was sufficiently expressed. The best double podding genotypes, i.e. those with 1535% of the podded nodes bearing double pods, were about one week earlier than their single podding counterparts and standard checks. A physiological study revealed that the double podding parental genotype 272-2 partitioned a relatively greater proportion (about 58%) of the total dry matter to pods compared to 4254% in the single podding genotypes. Double podding increased the total number of pods set, and thus the increased demand for assimilates may have precluded further production of stems and leaves, resulting in an earlier transition of reproductive growth to physiological maturity. Days to flowering was positively associated with days to maturity, and partial path analysis revealed that days to flowering contributed to days to maturity indirectly via days to first pod maturity. Days to flowering explained 32% of the variation in days to first pod maturity. However, the short internode trait had an undesirable effect, in that all the short internode segregants were too late to mature. <p>Genetic studies revealed that days to flowering was determined by two major genes plus polygenes in chickpea in the short-season temperate environment of western Canada. The two major genes control over 65% of the phenotypic variation. Also, the additive component of genetic variance was significant for days to first podding, days to first pod maturity, reproductive period, and days to maturity; which is desirable for development of superior inbred cultivars of chickpea. These key phenological traits are interrelated but could be manipulated separately in the breeding process. Additional gain in earliness of crop maturity may be achieved through combined selection for these traits.
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Tree Diameter Growth : Variations And Demographic Niches In A Tropical Dry Forest Of Southern IndiaNath, Cheryl D 07 1900 (has links)
Tree growth influences forest community dynamics and responses to environmental variations, but currently is not well understood. Tree growth in highly diverse wet tropical forests have been well studied and characterised compared to the species-poor dry tropical forests. Thus, it is not clear if growth rates and community dynamics of dry forests are similar to those of wet forests, given the longer dry season, greater rainfall variability, more open canopy and lower number of species in dry forests. This thesis focuses on identifying important factors that influence tree diameter growth rates in the dry tropical forest at Mudumalai, southern India, and also compares growth patterns at this dry forest with those at moister forests. The thesis thus contributes towards closing the gap in understanding of tree growth patterns across the tropics.
An initial analysis involving matrix-based population projections of four common canopy species at Mudumalai showed that variations in diameter growth have the potential to drastically modify population trajectories of dominant species. Thus the main focus of this thesis is aimed at identifying the important intrinsic and extrinsic factors affecting growth in this dry forest, as this information could be useful for future management of the forest. The second important aim of the thesis was to find out if growth rates are influenced by different sets of factors in tropical dry versus moist forests.
A large permanent 50ha plot vegetation monitoring plot was set up in 1988-89 in the Mudumalai dry deciduous forest, and was subsequently monitored annually by staff of the Centre for Ecological Sciences. Data used in this thesis represent a 12-year interval between 1988 and 2000. Girth measurements were obtained from all woody tree stems ≥1cm in diameter every four years during this 12 year interval, which provided three census intervals of diameter increment data on >13,000 trees. For the comparison between dry and moist deciduous forests, data were obtained from a similar large plot maintained and monitored at the Barro Colorado Island (BCI) in Panama.
Influences of the intrinsic factors, tree size, individual identity, species identity and growth form, were examined using t-tests, Wilcoxon signed ranks tests, linear regressions, analysis of variance (ANOVA), principal components analysis (PCA) and cluster analysis. Among the intrinsic factors tested, species identity explained approximately 20% of growth rates at the community level, while tree diameter explained less of growth variation, and growth form had a minor influence on growth.
Growth rates also were examined for variations across the three census intervals, and for relationships with rainfall and survival from fire. Statistical tests included t-tests, Wilcoxon and other non-parametric sign tests, logistic regression and ANOVA. Most species and individuals showed significant reductions of growth in the second census interval (1992-1996), and growth rates of most trees were positively related to rainfall. Growth rate variations generally were not related to survival from fire, and few species were capable of escaping fire mortality by fast growth.
Spatial environmental influences were tested in the commonest fifteen species, using five habitat categories, local elevation, slope, aspect, and the biotic neighbourhood variables of local conspecific and heterospecific density. Statistical tests included analysis of covariance, multiple linear regression and redundancy analysis. The tests were quadrat-based or individual-based, and species' growth responses were tested at different levels of distance and spatial scale. Topographic features and habitat categories had ephemeral effects on species growth. Only the most dominant species, Lagerstroemia microcarpa, showed consistent conspecific neighbour density effects. Redundancy analysis using a subset of common species and environmental factors did not reveal common growth responses to spatial environmental factors.
Comparison of factors influencing growth at Mudumalai versus at BCI using multiple factor ANOVA and multiple linear regressions showed a similar influence of temporal variation at the two sites, but stronger and more widespread influence of tree size (diameter) at BCI. The greater influence of tree size at BCI may be related to greater light limitation in this dense moist forest. Spatial environmental factors had weak influences at both plots. Species were less differentiated from each other at the more diverse BCI plot compared to the relatively species-poor Mudumalai plot, suggesting that species' growth niches may be weakly related to diversity across tropical forests.
Overall the results showed that among the factors tested species identity and census intervals were the most important influences on diameter growth at the Mudumalai dry deciduous forest. Tree diameter was less important and less consistent in affecting growth at the Mudumalai dry forest, contrary to expectations based on moist tropical forests where this relationship has been established previously. When comparing Mudumalai and BCI, the relative importance of different factors was different at the two sites, and the most important difference was a dominant influence of light limitation at the wetter forest in Panama.
In terms of management applications, this study showed that fires at Mudumalai might be an inescapable source of mortality for many vulnerable species, and improved fire management is crucial for long term survival of species in this dry forest. At a larger scale, light and other environmental variables were found to influence growth differently at Mudumalai compared to BCI. This suggests that location-specific responses may be important for projections of tree biomass and carbon sequestration, especially under future climatic change scenarios.
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Improved inhalation therapies of brittle powdersCarvalho, Simone Raffa 03 March 2015 (has links)
Advancements in pulmonary drug delivery technologies have improved the use of dry powder inhalation therapy to treat respiratory and systemic diseases. Despite remarkable improvements in the development of dry powder inhaler devices (DPIs) and formulations in the last few years, an optimized DPI system has yet to be developed. In this work, we hypothesize that Thin Film Freezing (TFF) is a suitable technology to improve inhalation therapies to treat lung and systemic malignancies due to its ability to produce brittle powder with optimal aerodynamic properties. Also, we developed a performance verification test (PVT) for the Next Generation Cascade Impactor (NGI), which is one of the most important in vitro characterization methods to test inhalation. In the first study, we used TFF technology to produce amorphous and brittle particles of rapamycin, and compared the in vivo behavior by the pharmacokinetic profiles, to its crystalline counterpart when delivered to the lungs of rats via inhalation. It was found that TFF rapamycin presented higher in vivo systemic bioavailability than the crystalline formulation. Subsequently, we investigated the use of TFF technology to produce triple fixed dose therapy using formoterol fumarate, tiotropium bromide and budesonide as therapeutic drugs. We investigated applications of this technology to powder properties and in vitro aerosol performance with respect to single and combination therapy. As a result, the brittle TFF powders presented superior properties than the physical mixture of micronized crystalline powders, such as excellent particle distribution homogeneity after in vitro aerosolization. Lastly, we developed a PVT for the NGI that may be applicable to other cascade impactors, by investigating the use of a standardized pressurized metered dose inhaler (pMDI) with the NGI. Two standardized formulations were developed. Formulations were analyzed for repeatability and robustness, and found not to demonstrate significant differences in plate deposition using a single NGI apparatus. Variable conditions were introduced to the NGI to mimic operator and equipment failure. Introduction of the variable conditions to the NGI was found to significantly adjust the deposition patterns of the standardized formulations, suggesting that their use as a PVT could be useful and that further investigation is warranted. / text
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Inclusão de milho desintegrado com palha e sabugo em silagem de milheto forrageiro / Crumbled corn cob and inclusion with straw in millet of forage silageSilva, Vanderli Luciano da 19 February 2016 (has links)
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Previous issue date: 2016-02-19 / This study aimed to evaluate the chemical composition and fermentation characteristics of silage
millet farming ADR500 under the inclusion of different levels of corn disintegrated with straw and
cob (CEC): 0%, 5%, 10% and 15%, after 78 days of vegetative growth and observe his capacity as
moisture scavenger in silage. The experimental design was completely randomized with 4
treatments and 4 replications, totaling 16 experimental units. Data were submitted to analysis of
variance, means were compared by 5% Tukey test and regression analysis for the inclusion levels.
dry matter content (DM) determined in silage differ (P <0.05) as a function of the MDPS inclusion
levels, ranging from 26.53% to 38.69% control treatment and for treatment with higher level
inclusion. For values of organic matter found a significant difference only from the IV treatment
with 15% inclusion of CEC (P <0.05) compared to other treatments. Regarding crude protein (CP)
observed a linear increase (P <0.05) due to the increase of CEC levels, ranging between 9.46% and
14.92%. NDF and the FDA determined in silages ranged from 58.50% to 66.25% and 31.25% for
FDA to 38.50 for the FDA so there significant differences between treatments. For certain ether
extract in silages millet forage with inclusion of MDPS ranged from 3.13 to 3.95%. The content of
mineral matter (MM) showed a significant difference (P <0.05) according to the MDPS inclusion
levels, ranging from 5.26 to 7.55%. The inclusion of MDPS reduced (P <0.05) losses gases and
effluents in all the treatments, ranging from 6.10 to 3.48 for gas losses and 9.05 to 17.28 for losses
effluent and contributed significantly in the dry matter recovery process (MS). The buffer power
values (PT), pH and ammonia-N were influenced (P <0.05) by the inclusion of different levels of
ground ear corn silage. The levels of acetic, propionic, butyric and lactic, so influenced by the
addition of ground ear corn silage. The soluble carbohydrate values have an increasing depending
on the MDPS inclusion levels, proving to be efficient in their use to improve the fermentation
profile of silages. / Objetivou-se avaliar a composição químico-bromatológica e as características fermentativas da
silagem de milheto forrageiro, cultivar ADR500 sob a inclusão de diferentes níveis de milho
desintegrado com palha e sabugo (MDPS): 0%, 5%, 10% e 15%, aos 78 dias de crescimento
vegetativo e observar sua capacidade como sequestrante de umidade na silagem. O delineamento
experimental utilizado foi inteiramente casualizado com 4 tratamentos e 4 repetições, totalizando
16 unidades experimentais. Os dados foram submetidos à análise de variância, as médias
comparadas pelo teste de Tukey a 5% e análise de regressão para os níveis de inclusão. Os teores
de matéria seca (MS) determinados na silagem diferiram (P<0,05) em função dos níveis de
inclusão do MDPS, com variação de 26,53% para o tratamento controle e 38,69% para o
tratamento com maior nível de inclusão. Para os valores de matéria orgânica encontrados houve
diferença significativa apenas do tratamento IV com 15% de inclusão de MDPS (P<0,05)
comparando aos demais tratamentos. Em relação à proteína bruta (PB) observou-se aumento linear
(P<0,05) em função da elevação dos níveis de MDPS, variando entre 9,46% e 14,92%. Os teores
de FDN e FDA determinados nas silagens variaram entre 58,50% até 66,25% para FDA e 31,25%
até 38,50 para o FDA havendo assim diferenças significativas entre os tratamentos. Para o extrato
etéreo determinado nas silagens de milheto forrageiro com inclusão de MDPS variaram entre 3,13
a 3,95%. O conteúdo de matéria mineral (MM) apresentou diferença significativa (P<0,05) em
função dos níveis de inclusão de MDPS, com variação de 5,26 a 7,55%. A inclusão de MDPS
reduziu (P<0,05) as perdas por gases e efluentes em todos os tratamentos avaliados, variando de
6,10 a 3,48 para as perdas por gases e 9,05 a 17,28 para as perdas por efluentes, e contribuiu
significativamente no processo de recuperação da matéria seca (MS). Os valores de poder tampão
(PT), pH e N-amoniacal foram influenciados (P<0,05) pela inclusão dos diferentes níveis de
MDPS à silagem. Os teores dos ácidos acético, propiônico, butírico e lático, forma influenciados
pela adição de MDPS na silagem. Os valores de carboidratos solúveis tiveram um aumento
crescente em função dos níveis de inclusão do MDPS, demonstrando ser eficiente em seu uso para
melhorar o perfil fermentativo da silagem.
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Eco-Hydrology of a Seasonally Dry Tropical Forest : Tree Growth, Belowground Water Dynamics and Drought-VulnerabilityTarak, Rutuja Chitra January 2016 (has links) (PDF)
Tropical forests are storehouses of more thanhalf of the world‘s biodiversity and play a key role in global carbon, water and energy cycles. However, as a consequence of rapid anthropogenic climate change, biodiversity and climate functions of these forests are under a threat. Climate is changing not only in mean state but its variability is increasing, with extreme events such as droughts, heat waves and storms also rising. Water is fundamental to plants‘ existence, and in the tropics, is a key determinant of plant species‘richness, composition, growth and survival. There is thus an increasing interest in understanding how changing rainfall may cause functional changes in forests or change their species composition. Therefore, the overarching goal of thisdissertation was to understand the impact of water variability on tropical forest tree growth and vulnerability to drought.Forest tree growth along spatial and temporal rainfall gradientsObservational studies that measure whole forest tree growth along spatial or temporal gradients of rainfall are the most common way of formulating forest growth response curves to water availability, when manipulative experiments are cost-prohibitive or impractical (fire or large mammal disturbance). In the tropics, since very few species show anatomically distinct tree rings, estimating tree growth from trunk diameter is the standard practice to obtain growth patterns across species. However, this method—of equating woody growth to diameter change--is susceptible to bias from water-induced stem flexing. In the absence of bias correction, temporal variability in growth is likely to be overestimated and incorrectly attributed to fluctuations in resource availability, especially in forests with high seasonal and inter-annual variability in water. This problem has been largely ignored in the absence of any corrective measure and due to under-appreciation of the magnitude of error. While diameter re-censuses in permanent sampling plots (PSPs) have been most commonly done at 3-5 year scale (using a graduate tape), increasingly they are done at seasonal and annual scales (using band dendrometers) to closely match variation in rainfall, the scales at which hydrostatic bias may be greater in magnitude relative to woody growth. Besides, along a spatial rainfall gradient, inter-annual variability in water may vary, causing systematic differences in the hydrostatic bias for forests along the gradient. Therefore, one broad objective of this thesis was to evaluate the problem of hydrostatic bias in whole forest growth-rainfall relationship at annual and supra-annual scales, for temporal as well as spatial rainfall gradients and propose and test a novel corrective solution.Further, it also examines if growth-diameter relationship vary along the spatial gradient, which it may arise due to differences in light environments and/or disturbance history and species composition.
The missing link of Eco-hydrology Differential responses of tree species in terms of growth and survival to variation in water that they can access, the proximate cause is likely shaped through their life-history strategies, the ultimate cause. However, we neither know the depths at which the diverse tree species in a forest draw water from and its dynamics, nor variation in water at those depths vis-à-vis rainfall patterns—for lack of appropriate methods. This has been a key missing link in understanding how water shapes trees‘ life-history strategies, their demographic trade-offs and co-existence, and also our predictive ability to determine species-specific responses to changing rainfall patterns, especially droughts. Since droughts are highly stochastic events and trees‘ responses to their drought ―experiences‖ may be revealed at decadal scales, long-term evaluations are key. Therefore, the second broad objective of this thesis was to develop a framework to determine trees’ water uptake depths, variation in water availability at those depths and trees’ demographic responses over multiple decades. From this, to understand how belowground hydrology shapes drought-vulnerability, demographic trade-offs and coexistence of forest tree species. This thesis titled—Eco-Hydrology of a Seasonally Dry Tropical Forest: Tree Growth, Belowground Water Dynamics and Drought-Vulnerability—is organized as follows: Chapter 1 lays down an introduction to the thesis, followed by a description of the study site and datasets used in the thesis in Chapter 2. This thesis uses a variety of methods and multiple datasets, all of which are from the protected Seasonally Dry Tropical Forests of the Western Ghats in southern India in the Mudumalai and Bandipur National Parks. It is then followed by three data chapters: Chapter 3 describes the seasonal fluctuations in a five year long (1980-1985) tree diameter time series (using dendrometers) of a Seasonally Dry Tropical Forest in Bandipur National Park to illustrate the issue of hydrostatic stem-flexing. It investigates the possibility that band dendrometers may themselves underestimate stem shrinkage at diurnal or seasonal scale. It also evaluates if there could be a best season and time of the day for undertaking forest diameter censuses that can minimize hydrostatic bias. Chapter 4(published in Forest Ecology and Management)measures the hydrostatic bias in a sample of trees in a 50 ha PSP of a Seasonally Dry Tropical Forest in Mudumalai National Park, and proposes a novel way to correct this bias at the whole community level in the 20 year long 4-year interval growth time series. Chapter 5 (in review with Environmental Research Letters) investigates and presents two new confounding factors in growth-rainfall relationships along a spatial rainfall gradient: hydrostatic bias and size-dependency in growth rates. For this it evaluates forest tree growth estimates in seven 1-ha PSPs (~800 trees, 3-year annual time series 9using dendrometers) along a 1000 mm rainfall gradient spanning a mesic savanna-moist forest transition in Mudumalai National Park. Using the period for which seasonal diameter time series was available (2 yrs), it evaluates if the extent of seasonal fluctuations systematically vary along the gradient—most likely due to hydrostatic stem flexing. It also describes the presence of an anomalous size-diameter relationship in the mesic savanna from a large plots (50 ha PSP, diameter records using graduated tape). These observations are then used to draw insights for ―space for time‖ substitution modeling. Chapter 6 (in prep for Nature Plants) analyses belowground water environments of trees over two decades (1992-2012), a period that includes a prolonged and intense drought, in the 50 ha PSP of a Seasonally Dry Tropical Forest in Mudumalai. It uses a locally parametarised dynamic hydrological model in which site rainfall is also a forcing variable. It then develops a novel dynamic growth model and inversely estimates water uptake depths for adult trees of all common species (include ~9000 trees) in the PSP from their above-ground growth patterns over two decades vis-à-vis belowground water availability at multiple depths. It then examines if species‘ water uptake depth obtained thus is a predictor of their drought-driven mortality. Finally, this is used to evaluate the hydrological niche partitioning tree species operate under and how that drives their water uptake strategies, demographic trade-offs, and drought-vulnerability. Summarizes the thesis and suggests future directions
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