Relation between respiratory variations in pulse oximetry plethysmographic waveform amplitude and arterial pulse pressure in ventilated patients.

IntroductionRespiratory variation in arterial pulse pressure is a reliable predictor of fluid responsiveness in mechanically ventilated patients with circulatory failure. The main limitation of this method is that it requires an invasive arterial catheter. Both arterial and pulse oximetry plethysmographic waveforms depend on stroke volume. We conducted a prospective study to evaluate the relationship between respiratory variation in arterial pulse pressure and respiratory variation in pulse oximetry plethysmographic (POP) waveform amplitude.MethodThis prospective clinical investigation was conducted in 22 mechanically ventilated patients. Respiratory variation in arterial pulse pressure and respiratory variation in POP waveform amplitude were recorded simultaneously in a beat-to-beat evaluation, and were compared using a Spearman correlation test and a Bland-Altman analysis.ResultsThere was a strong correlation (r2 = 0.83; P < 0.001) and a good agreement (bias = 0.8 +/- 3.5%) between respiratory variation in arterial pulse pressure and respiratory variation in POP waveform amplitude. A respiratory variation in POP waveform amplitude value above 15% allowed discrimination between patients with respiratory variation in arterial pulse pressure above 13% and those with variation of 13% or less (positive predictive value 100%).ConclusionRespiratory variation in arterial pulse pressure above 13% can be accurately predicted by a respiratory variation in POP waveform amplitude above 15%. This index has potential applications in patients who are not instrumented with an intra-arterial catheter

Characterization of Macrophomina phaseolina Infecting Chia Plants

Microbial organisms have caused detrimental effects to agricultural plants by significantly decreasing their plant growth yield and it’s nutritional qualities, leading to high levels of economic losses in society. Salvia Hispanica L., commonly known as chia, is becoming a rising agricultural crop because of its favorable nutritional qualities. Chia seeds have a high concentration of α-linolenic acid, commonly known as omega-3 fatty acids) which provide several different health benefits, in addition to being a rich source of protein and fiber. Chia field trial conducted by the Atamian lab during summer 2018, experienced high levels of disease incidence characterized by root rot, plant wilting, and eventual death of three-month-old chia plants. The fungus was isolated and identified as Macrophomina phaseolina based on its morphological analysis on potato dextrose agar plates. Macrophomina phaseolina is a widespread fungus that causes a high mortality rate in nursery plats as well as in agricultural crops such as soybean, maize, sorghum, and cotton. The fungus damages the root system of the plant host, resulting in the inability of the root to obtain the required nutrients and water for proper growth of the plant. The objective of this project was to use molecular techniques to confirm the accuracy of the morphological analysis and further characterize the fungus at the molecular level. The DNA of Macrophomina phaseolina was cloned through the process of A tailing, ligation, and transformation into E. coli cells, and then plasmids from the surviving cultured E coli. cells were sent to the lab for sequencing of the genes MPK-1, ITS 1 and 2, and SSU rRNA. Using the other strains of Macrophomina phaseolina in the NCBI database, the resulting gene sequences were compared to deduce that the fungus present was Macrophomina phaseolina, and if there was a presence of genetic variability between the strains infecting chia plants to previous cases in other plants

Identification and Characterization of Amino Acid Exporters in Arabidopsis thaliana

Amino acids are the major form of nitrogen (N) transported within the plant body, and their transport between different plant tissues through the xylem and the phloem is indispensable for optimal growth. Such transport processes rely on critical import and export steps at the cellular membranes, mediated by transporters. Many amino acid importers and their roles in the plant body have previously been discovered, providing not only a better understanding of amino acid transport mechanisms but also tools to improve N use efficiency of crops. However, amino acid exporters are not well studied due to a lack of efficient techniques for their identification. The overall goal of this Ph.D. was to advance our understanding of amino acid export in plants by 1) developing methods in Saccharomyces cerevisiae that allow a faster identification of putative amino acid exporters and 2) investigating the roles of the identified amino acid exporters using genetic tools available in Arabidopsis thaliana. The studies presented here revealed several novel amino acid exporter proteins, Usually Multiple Acids Move In and Out Transporters (UMAMIT) 14, UMAMIT24 and UMAMIT25, which mediated amino acid export when expressed in yeast, with little to no import activities. In plants, UMAMIT14 functions synergistically with previously characterized amino acid facilitator UMAMIT18 to mediate phloem unloading of shoot-derived amino acids. Knockout lines for these genes did not show any deleterious effects on yield; however the plants had reduced amino acid transfer from the shoot to the roots, as well as from roots to the growth medium. On the other hand, UMAMIT24 and UMAMIT25 are expressed in various seed tissues during embryogenesis, and are responsible for amino acid transport to the seed. An increased expression of UMAMIT24 and 25 using their own promoters increased the seed yields, whereas ectopic expression of UMAMIT transporters caused a stress response linked with an amino acid imbalance. The results suggest that optimizing key amino acid export steps in plants could benefit crop production, whereas excessive amino acid export can cause deleterious effects on plant growth

Reporting Charcoal Rot in Chia and Developing a Susceptibility Assay

Chia (Salvia Hispanica) cross breeds were planted in the summer of 2018 with the intent of selective breeding for agricultural benefit. Preexisting pathogens in the soil caused 40-50% fatality of adult plants. This was surprising due to the precursory knowledge that chia has antibiotic and antifungal oils (Elshafie et. al. 2018); chia was only recently documented to be susceptible to Fusarium wilt (Fusarium oxysporum). The primary pathogen responsible was identified as Macrophomina phaseolina (aka charcoal rot); a widespread soilborne pathogen which has multiple commercial hosts (Su et. al. 2001). M. phaesolina on wheat seed vector where used as inoculums (Brandari 2017) for chia to evaluate disease progression and symptoms in chia. Samples of this trial produced M. phaseolina from diseased chia tissues confirming susceptibility to M. phaseolina; in addition carefully sampled root and stem fractions identified the pathology of fungus from root to stem. The two parental varieties of the cross, chia-Pinta and chia-Tropic continue to be compared for their disease resistance to M. phaseolina. Identifying disease resistant genes allows for breeding of resistant cultivars, improving the marketability of chia

Modular interpretation of heterogeneous modeling diagrams into synchronous equations using static single assignment

The ANR project SPACIFY develops a domain-specific programming environment, Synoptic, to engineer embedded software for space applications. Synoptic is an Eclipse-based modeling environment which supports all aspects of aerospace software design. As such, it is a domain-specific environment consisting of heterogeneous modeling and programming principles defined in collaboration with the industrial partners and end users of the project : imperative synchronous programs, data-flow diagrams, mode automata, blocks, components, scheduling, mapping and timing. This article focuses on the essence and distinctive features of its behavioral or programming aspects : actions, flows and automata, for which we use the code generation infrastructure of the synchronous modeling environment SME. It introduces an efficient method for transforming a hierarchy of blocks consisting of actions (sequential Esterel-like programs), data-flow diagrams (to connect and time modules) and mode automata (to schedule or mode blocks) into a set of synchronous equations. This transformation minimizes the needed state variables and block synchronizations. It consists of an inductive static-single assignment transformation algorithm across a hierarchy of blocks that produces synchronous equations. The impact of this new transformation technique is twofold. With regards to code generation objectives, it minimizes the needed resynchronization of each block in the system with respects to its parents, potentially gaining substantial performance from way less synchronizations. With regards to verification requirements, it minimizes the number of state variables across a hierarchy of automata and hence maximizes model checking performances

Compositional design of isochronous systems

International audienceThe synchronous modeling paradigm provides strong correctness guarantees for embedded system design while requiring minimal environmental assumptions. In most related frameworks, global execution correctness is achieved by ensuring the insensitivity of (logical) time in the program from (real) time in the environment. This property, called endochrony or patience, can be statically checked, making it fast to ensure design correctness. Unfortunately, it is not preserved by composition, which makes it difficult to exploit with component-based design concepts in mind. Compositionality can be achieved by weakening this objective, but at the cost of an exhaustive state-space exploration. This raises a trade-off between performance and precision. Our aim is to balance it by proposing a formal design methodology that adheres to a weakened global design objective: the non-blocking composition of weakly endochronous processes, while preserving local design objectives for synchronous modules. This yields an effective and cost-efficient approach to compositional synchronous modeling

Polychronous Interpretation of Synoptic, a Domain Specific Modeling Language for Embedded Flight-Software

The SPaCIFY project, which aims at bringing advances in MDE to the satellite flight software industry, advocates a top-down approach built on a domain-specific modeling language named Synoptic. In line with previous approaches to real-time modeling such as Statecharts and Simulink, Synoptic features hierarchical decomposition of application and control modules in synchronous block diagrams and state machines. Its semantics is described in the polychronous model of computation, which is that of the synchronous language Signal.Comment: Workshop on Formal Methods for Aerospace (FMA 2009