Evaluation of geostatistical techniques to estimate the spatial distribution of aboveground biomass in the Amazon rainforest using high-resolution remote sensing data

ABSTRACT The spatial distribution of forest biomass in the Amazon is heterogeneous with a temporal and spatial variation, especially in relation to the different vegetation types of this biome. Biomass estimated in this region varies significantly depending on the applied approach and the data set used for modeling it. In this context, this study aimed to evaluate three different geostatistical techniques to estimate the spatial distribution of aboveground biomass (AGB). The selected techniques were: 1) ordinary least-squares regression (OLS), 2) geographically weighted regression (GWR) and, 3) geographically weighted regression - kriging (GWR-K). These techniques were applied to the same field dataset, using the same environmental variables derived from cartographic information and high-resolution remote sensing data (RapidEye). This study was developed in the Amazon rainforest from Sucumbíos - Ecuador. The results of this study showed that the GWR-K, a hybrid technique, provided statistically satisfactory estimates with the lowest prediction error compared to the other two techniques. Furthermore, we observed that 75% of the AGB was explained by the combination of remote sensing data and environmental variables, where the forest types are the most important variable for estimating AGB. It should be noted that while the use of high-resolution images significantly improves the estimation of the spatial distribution of AGB, the processing of this information requires high computational demand.

Development of computational and experimental methods for biomass composition and evaluation of its impact in genome-scale models prediction

The use of genome-scale metabolic models has been rapidly increasing in fields such as metabolic engineering. An important part of a metabolic model is the biomass equation since this reaction will ultimately determine the predictive capacity of the model in terms of essentiality and flux distributions. Thus, in order to obtain a reliable metabolic model the biomass precursors and their coefficients must be as precise as possible. Ideally, determination of the biomass composition would be performed experimentally, but when no experimental data are available this is established by approximation to closely related organisms. Computational methods however, can extract some information from the genome such as amino acid and nucleotide compositions. The main objectives of this study were to compare the biomass composition of several organisms and to evaluate how biomass precursor coefficients affected the predictability of several genome-scale metabolic models by comparing predictions with experimental data in literature. For that, the biomass macromolecular composition was experimentally determined and the amino acid composition was both experimentally and computationally estimated for several organisms. Sensitivity analysis studies were also performed with the Escherichia coli iAF1260 metabolic model concerning specific growth rates and flux distributions. The results obtained suggest that the macromolecular composition is conserved among related organisms. Contrasting, experimental data for amino acid composition seem to have no similarities for related organisms. It was also observed that the impact of macromolecular composition on specific growth rates and flux distributions is larger than the impact of amino acid composition, even when data from closely related organisms are used.

An efficient Azorean thermophilic consortium for lignocellulosic biomass degradation

[Excerpt] Lignocellulosic plant biomass is being envisioned by biorefinery industry as an alternative to current petroleum platform because of the large scale availability, low cost and environmentally benign production. The industrial bioprocessing designed to transform lignocellulosic biomass into biofuels are harsh and the enzymatic reactions may be severely compromised reducing the production of fermentable sugars from lignocellulosic biomass. Thermophilic bacteria consortium are a potential source of cellulases and hemicellulases adapted to extreme environmental conditions, which can be exploited as a new source for the development of more robust enzymatic cocktails. (...)

Candida tropicalis biofilms: biomass, metabolic activity and secreted aspartyl proteinase production

According to epidemiological data, Candida tropicalis has been related to urinary tract infections and haematological malignancy. Several virulence factors seem to be responsible for C. tropicalis infections, for example: their ability to adhere and to form biofilms onto different indwelling medical devices; their capacity to adhere, invade and damage host human tissues due to enzymes production such as proteinases. The main aim of this work was to study the behaviour of C. tropicalis biofilms of different ages (24120 h) formed in artificial urine (AU) and their ability to express aspartyl proteinase (SAPT) genes. The reference strain C. tropicalis ATCC 750 and two C. tropicalis isolates from urine were used. Biofilms were evaluated in terms of culturable cells by colony-forming units enumeration; total biofilm biomass was evaluated using the crystal violet staining method; metabolic activity was evaluated by XTT assay; and SAPT gene expression was determined by real-time PCR. All strains of C. tropicalis were able to form biofilms in AU, although with differences between strains. Candida tropicalis biofilms showed a decrease in terms of the number of culturable cells from 48 to 72 h. Generally, SAPT3 was highly expressed. C. tropicalis strains assayed were able to form biofilms in the presence of AU although in a strain- and time-dependent way, and SAPT genes are expressed during C. tropicalis biofilm formation.

Combustion of alternative biomass fuels in a domestic boiler and in a large-scale furnace

Programa Doutoral em Engenharia Mecânica.

The role of biomass and biorefineries in a sustainable future

Some o f the biggest issues facing humanity in the 21st century include energy security, global warming and resource scarcity. These issues will affect every nation and Ireland is no exception. There is much research underway to uncover technologies that will allow the world to overcome such problems, but none offer the flexibility o f biomass. Unlike other sustainable technologies, which offer a solution to one or at most two o f the above problems, biomass as demonstrated by the author, can play a part in mitigating all o f the above problems. It has been known for some time that biomass can be used in various ways as a form o f renewable energy, but with the development o f biorefineries biomass can be used to produce material as well as fuel products. In this report the author has looked at the viability and benefits o f biomass, bioenergy and biorefining in Ireland. The author has demonstrated that such technologies when implemented correctly are sustainable from an economic, environmental and societal point o f view. The author has shown in this thesis that abundant supplies o f biomass make bio re fineries a viable business opportunity in Ireland and has shown how a number o f biorefinery scenarios have the potential to be extremely profitable. The author has evaluated the profitability o f material product-based bio re fineries as well as fuel productbased configurations. The author demonstrated that value-added co-products help to make bio refineries profitable even when excise-relief is not granted on bio fuels. In this thesis the author has revealed some o f the problems that bioenergy and biorefineries have had to overcome to date and examines challenges that remain for bioenergy and biorefining, and looks at the future opportunities for bio fuels. This report concludes that biomass and biorefining has exciting business potential while offering unique opportunities to mitigate the problems o f the future.

Life history, biomass and production of Coronatella rectangula (Branchiopoda, Anomopoda, Chydoridae) from Minas Gerais

Species of Chydoridae provide the main diversity of the Cladocera. These organisms have been the subject of many studies; some dealing with their role in energy flow in aquatic ecosystems, since they inhabit the littoral region of water bodies which undergo the first impacts from anthropic activities. The aim of this study is to increase knowledge about the life cycle of Coronatella rectangula (Sars, 1861), a species found in several water bodies in the state of Minas Gerais, Brazil. The life cycle was determined by the culture of parthenogenetic females under controlled conditions in the laboratory. Experimental cultures were maintained in growth chambers at a constant temperature of 23.6(±0.5)ºC, through a 12 h light/12 h dark photoperiod. The organisms were fed on a suspension of Pseudokirchneriella subcapitata (Chlorophyceae) (10(5) cells.mL-1), and 0.02 mL of a mixed suspension of yeast and fish ration added per organism in equal proportions (1:1). Fifty parthenogenetic females with eggs were isolated and maintained until they produced neonates. Thirty of these neonates that had less than 24 hours were put in polypropylene bottles of 50 mL and kept in a germination chamber. These organisms were observed daily to obtain the parameters of the life cycle. Biomass and secondary production were also calculated. The embryonic development time of the specimens of C. rectangula was 1.68(±0.13) days and the time to reach primipara, was 2.48(±0.45) days. The mean fecundity of C. rectangula was two eggs/female/brood and the total number of eggs produced by the female during its life cycle was 27.8 eggs. During the whole life cycle, specimens of C. rectangula had a maximum of 14 seedlings, with two instars in the juvenile stage. Total biomass for C. rectangula was 36.66 µgDW.m-3(9.83 for the juvenile stage and 26.82 µgDW.m-3 for adults), and secondary production was 12.10 µgDW.m-3.day-1(8.34 µgDW.m-3.day-1 for egg production and 3.76 µgDW.m-3.day-1 for the juvenile stage).

Effects of atmospheric carbon dioxide fertilization on biomass and secondary metabolites of some plant species with pharmacological interes under greenhouse conditions

RESUMEN El aumento del CO2 atmosférico debido al cambio global y/o a las prácticas hortícolas promueve efectos directos sobre crecimiento vegetal y el desarrollo. Estas respuestas pueden ocurrir en ecosistemas naturales, pero también se pueden utilizar para aumentar la producción de algunas plantas y de algunos compuestos secundarios. El actual trabajo intenta estudiar los efectos del enriquecimiento atmosférico del CO2 bajo condiciones de invernadero en el crecimiento y la concentración y la composición de metabolitos secundarios de Taxus bacatta, Hypericum perforatum y Echinacea purpurea en condiciones ambientales mediterráneas. La fertilización del CO2 muestra perspectivas interesantes para la mejorara y aplicabilidad de técnicas hortícolas para aumentar productividad de plantas medicinales, a pesar de diferencias claras entre la especie. En general esta técnica promueve aumentos importantes y significativos en producción primaria y, en algunos casos, también en compuestos secundarios. Esto tiene una gran importancia hortícola porque la productividad a nivel de cosecha total aumenta, directamente porque se aumenta la concentración e indirectamente porque se aumenta la biomasa. SUMMARY The increase of atmospheric CO2 due to global change and/or horticultural practices promotes direct effects on plant growth and development. These responses may occur in natural ecosystems, but also can be used to increase the production of some plants and some secondary compounds. Present work tries to study the effects of atmospheric CO2 enrichment under greenhouse conditions on growth and in the concentration and composition of secondary metabolites of Taxus bacatta, Hypericum perforatum and Echinacea purpurea under Mediterranean environmental conditions. CO2 fertilization shows interesting perspectives to increase and improve horticultural techniques in order to increase plant medicinal productivity, in spite of clear differences among the species. In general this technique promotes important and significant increases in primary productivity and, in some cases, also in secondary compounds. This has a great horticultural relevance because the total productivity of this kind of products increase at crop level, directly because concentration is increased and /or indirectly because biomass is increased. RESUM L'augment del CO2 atmosfèric a causa del canvi global i/o a les pràctiques hortícoles promou efectes directes sobre creixement vegetal i el desenvolupament. Aquestes respostes poden ocórrer en ecosistemes naturals, però també es poden utilitzar per a augmentar la producció d'algunes plantes i d'alguns compostos secundaris. L'actual treball intenta estudiar els efectes de l'enriquiment atmosfèric del CO2 sota condicions d'hivernacle en el creixement i la concentració i la composició de metabòlits secundaris de Taxus bacatta, Hypericum perforatum i Echinacea purpurea en condicions ambientals mediterrànies. La fertilització del CO2 mostra perspectives interessants per a la millora i aplicabilitat de tècniques hortícoles per a augmentar productivitat de plantes medicinals, a pesar de diferències clares entre l'espècie. En general aquesta tècnica promou augments importants i significatius en producció primària i, en alguns casos, també en compostos secundaris. Això té una gran importància hortícola perquè la productivitat a nivell de collita total augmenta, directament perquè s'augmenta la concentració i indirectament perquè s'augmenta la biomassa.

Peroxisomal polyhydroxyalkanoate biosynthesis is a promising strategy for bioplastic production in high biomass crops.

Polyhydroxyalkanoates (PHAs) are bacterial carbon storage polymers with diverse plastic-like properties. PHA biosynthesis in transgenic plants is being developed as a way to reduce the cost and increase the sustainability of industrial PHA production. The homopolymer polyhydroxybutyrate (PHB) is the simplest form of these biodegradable polyesters. Plant peroxisomes contain the substrate molecules and necessary reducing power for PHB biosynthesis, but peroxisomal PHB production has not been explored in whole soil-grown transgenic plants to date. We generated transgenic sugarcane (Saccharum sp.) with the three-enzyme Ralstonia eutropha PHA biosynthetic pathway targeted to peroxisomes. We also introduced the pathway into Arabidopsis thaliana, as a model system for studying and manipulating peroxisomal PHB production. PHB, at levels up to 1.6%-1.8% dry weight, accumulated in sugarcane leaves and A. thaliana seedlings, respectively. In sugarcane, PHB accumulated throughout most leaf cell types in both peroxisomes and vacuoles. A small percentage of total polymer was also identified as the copolymer poly (3-hydroxybutyrate-co-3-hydroxyvalerate) in both plant species. No obvious deleterious effect was observed on plant growth because of peroxisomal PHA biosynthesis at these levels. This study highlights how using peroxisomal metabolism for PHA biosynthesis could significantly contribute to reaching commercial production levels of PHAs in crop plants.

Light receptor action is critical for maintaining plant biomass at warm ambient temperatures.

The ability to withstand environmental temperature variation is essential for plant survival. Former studies in Arabidopsis revealed that light signalling pathways had a potentially unique role in shielding plant growth and development from seasonal and daily fluctuations in temperature. In this paper we describe the molecular circuitry through which the light receptors cry1 and phyB buffer the impact of warm ambient temperatures. We show that the light signalling component HFR1 acts to minimise the potentially devastating effects of elevated temperature on plant physiology. Light is known to stabilise levels of HFR1 protein by suppressing proteasome-mediated destruction of HFR1. We demonstrate that light-dependent accumulation and activity of HFR1 are highly temperature dependent. The increased potency of HFR1 at warmer temperatures provides an important restraint on PIF4 that drives elongation growth. We show that warm ambient temperatures promote the accumulation of phosphorylated PIF4. However, repression of PIF4 activity by phyB and cry1 (via HFR1) is critical for controlling growth and maintaining physiology as temperatures rise. Loss of this light-mediated restraint has severe consequences for adult plants which have greatly reduced biomass.

Partitioning of reproduction in animal societies.

A key feature differentiating cooperative animal societies Is the apportionment of reproduction among individuals. Only recently have studies started to focus on intraspecific variability in the distribution of reproduction within animal societies, and the available data suggest that this variability might be greater than previously suspected. How can one account for intra-and interspecific variability in partitioning of reproduction? This Is one of the most intriguing problems in the study of social behaviour, and understanding the factors underlying this variability is one of the keys to understanding the properties of complex animal societies.

Energy partitioning for "fuzzy" atoms

The total energy of molecule in terms of 'fuzzy atoms' presented as sum of one- and two-atomic energy components is described. The divisions of three-dimensional physical space into atomic regions exhibit continuous transition from one to another. The energy components are on chemical energy scale according to proper definitions. The Becke's integration scheme and weight function determines realization of method which permits effective numerical integrations

One- and two-center physical space partitioning of the energy in the density functional theory

A conceptually new approach is introduced for the decomposition of the molecular energy calculated at the density functional theory level of theory into sum of one- and two-atomic energy components, and is realized in the "fuzzy atoms" framework. (Fuzzy atoms mean that the three-dimensional physical space is divided into atomic regions having no sharp boundaries but exhibiting a continuous transition from one to another.) The new scheme uses the new concept of "bond order density" to calculate the diatomic exchange energy components and gives them unexpectedly close to the values calculated by the exact (Hartree-Fock) exchange for the same Kohn-Sham orbitals

Partitioning of genetic (Rapd) variability among sexes and populations of the Barn Owl (Tyto alba) in Europe

The white Barn Owl subspecies (Tyto alba alba) is found in southern Europe and the reddish-brown subspecies (T a. guttata) in northern and eastern Europe. In central Europe, the two subspecies interbreed producing a large range of phenotypic variants. Because of the different ratios of the subspecies in different geographic regions, we predict that genetic variation should be greater in Switzerland than in Hungary. We tested this hypothesis by measuring genetic variation with the RAPD method. As predicted, the genetic differentiation within a Swiss population of Barn Owls was significantly greater than the variation within a Hungarian population. This suggests that gene flow is greater in central Europe than at the eastern limit of the Barn Owl distribution in Hungary. In both countries genetic variation was more pronounced in females than in males. As in other birds, this is probably because female Barn Owls are less philopatric than males. The number of migrants between Hungary and Switzerland is ca. 1 individual per generation; if calculated separately for the sexes, then 0.525 for males and ca. I for females (Nm values). The difference in the number of migrants between genders again is likely a consequence of higher male philopatry. The sexual differentiation is greater in the Swiss population than in the Hungarian and the genetic substructuring of the populations of the species is substantial. The reason for the considerable population substructuring could be the nonmigratory behavior and socially monogamous pairing of the species, as well as the geographical barriers (Alps) between the populations examined.