Deep EST profiling of developing fenugreek endosperm to investigate galactomannan biosynthesis and its regulation

Galactomannans are hemicellulosic polysaccharides composed of a (1 → 4)-linked β-D-mannan backbone substituted with single-unit (1 → 6)-α-linked D-galactosyl residues. Developing fenugreek (Trigonella foenum-graecum) seeds are known to accumulate large quantities of galactomannans in the endosperm, and were thus used here as a model system to better understand galactomannan biosynthesis and its regulation. We first verified the specific deposition of galactomannans in developing endosperms and determined that active accumulation occurred from 25 to 38 days post anthesis (DPA) under our growth conditions. We then examined the expression levels during seed development of ManS and GMGT, two genes encoding backbone and side chain synthetic enzymes. Based on transcript accumulation dynamics for ManS and GMGT, cDNA libraries were constructed using RNA isolated from endosperms at four ages corresponding to before, at the beginning of, and during active galactomannan deposition. DNA from these libraries was sequenced using the 454 sequencing technology to yield a total of 1.5 million expressed sequence tags (ESTs). Through analysis of the EST profiling data, we identified genes known to be involved in galactomannan biosynthesis, as well as new genes that may be involved in this process, and proposed a model for the flow of carbon from sucrose to galactomannans. Measurement of in vitro ManS and GMGT activities and analysis of sugar phosphate and nucleotide sugar levels in the endosperms of developing fenugreek seeds provided data consistent with this model. In vitro enzymatic assays also revealed that the ManS enzyme from fenugreek endosperm preferentially used GDP-mannose as the substrate for the backbone synthesis

Untangling the Interplay between Epidemic Spread and Transmission Network Dynamics

The epidemic spread of infectious diseases is ubiquitous and often has a considerable impact on public health and economic wealth. The large variability in the spatio-temporal patterns of epidemics prohibits simple interventions and requires a detailed analysis of each epidemic with respect to its infectious agent and the corresponding routes of transmission. To facilitate this analysis, we introduce a mathematical framework which links epidemic patterns to the topology and dynamics of the underlying transmission network. The evolution, both in disease prevalence and transmission network topology, is derived from a closed set of partial differential equations for infections without allowing for recovery. The predictions are in excellent agreement with complementarily conducted agent-based simulations. The capacity of this new method is demonstrated in several case studies on HIV epidemics in synthetic populations: it allows us to monitor the evolution of contact behavior among healthy and infected individuals and the contributions of different disease stages to the spreading of the epidemic. This gives both direction to and a test bed for targeted intervention strategies for epidemic control. In conclusion, this mathematical framework provides a capable toolbox for the analysis of epidemics from first principles. This allows for fast, in silico modeling - and manipulation - of epidemics and is especially powerful if complemented with adequate empirical data for parameterization

Exact analysis of summary statistics for continuous-time discrete-state Markov processes on networks using graph-automorphism lumping

We propose a unified framework to represent a wide range of continuous-time discrete-state Markov processes on networks, and show how many network dynamics models in the literature can be represented in this unified framework. We show how a particular sub-set of these models, referred to here as single-vertex-transition (SVT) processes, lead to the analysis of quasi-birth-and-death (QBD) processes in the theory of continuous-time Markov chains. We illustrate how to analyse a number of summary statistics for these processes, such as absorption probabilities and first-passage times. We extend the graph-automorphism lumping approach [Kiss, Miller, Simon, Mathematics of Epidemics on Networks, 2017; Simon, Taylor, Kiss, J. Math. Bio. 62(4), 2011], by providing a matrix-oriented representation of this technique, and show how it can be applied to a very wide range of dynamical processes on networks. This approach can be used not only to solve the master equation of the system, but also to analyse the summary statistics of interest. We also show the interplay between the graph-automorphism lumping approach and the QBD structures when dealing with SVT processes. Finally, we illustrate our theoretical results with examples from the areas of opinion dynamics and mathematical epidemiology

Photovoltaic powered irrigation system applied to familiary agriculture

CoordenaÃÃo de AperfeÃoamento de Pessoal de NÃvel SuperiorA presente dissertaÃÃo tem como objetivo principal analisar a viabilidade tÃcnica e financeira de um sistema fotovoltaico autÃnomo para bombeamento de Ãgua aplicado na irrigaÃÃo de uma unidade de produÃÃo agrÃcola familiar. A unidade agrÃcola pesquisada està instalada no NÃcleo de Ensino e Pesquisa em Agricultura Urbana (NEPAU), que atua em parceria com o LaboratÃrio de Energias Alternativas (LEA), situados no Campus do PICI da Universidade Federal do CearÃ. A unidade ocupa uma Ãrea Ãtil de 43 m2, com um reservatÃrio de Ãgua que simula um aÃude, lago ou poÃo com capacidade de 3.534 litros, um motor bomba de 12 VDC e um mÃdulo fotovoltaico de 135 Wp. O sistema de irrigaÃÃo à constituÃdo por 12 micro-aspersores com pressÃo de trabalho de 7 psi, com raio de alcance de 1,2 m e vazÃo de 0,6 l/min. A unidade de produÃÃo consumiu 31.592 litros de Ãgua e demandou 5,2 kWh de energia elÃtrica ao longo de 44 dias de produÃÃo do coentro. Um sensor de umidade do solo foi utilizado para controlar a umidade do solo o que permitiu economizar 3.608 litros de Ãgua e 0,6 kWh de energia elÃtrica na produÃÃo de 23 kg de coentro. O custo de implantaÃÃo do sistema fotovoltaico de bombeamento desenvolvido foi de R$1.694,00. As eficiÃncias do mÃdulo fotovoltaico, conjunto motobomba e global foram de 8,4$ 1,694.00. The efficiencies of photovoltaic module, pump and global set were 8.4%, 42% and 3.5%, respectively. The return on capital invested time is 10 years without regard to any allowance and 8.4 years for a 20% allowance on capital invested in the acquisition of equipment