Chemical modification of L-glutamine to alpha-amino glutarimide on autoclaving facilitates Agrobacterium infection of host and non-host plants: A new use of a known compound

Background

Accidental autoclaving of L-glutamine was found to facilitate the Agrobacterium infection of a non host plant like tea in an earlier study. In the present communication, we elucidate the structural changes in L-glutamine due to autoclaving and also confirm the role of heat transformed L-glutamine in Agrobacterium mediated genetic transformation of host/non host plants.

Results

When autoclaved at 121°C and 15 psi for 20 or 40 min, L-glutamine was structurally modified into 5-oxo proline and 3-amino glutarimide (α-amino glutarimide), respectively. Of the two autoclaved products, only α-amino glutarimide facilitated Agrobacterium infection of a number of resistant to susceptible plants. However, the compound did not have any vir gene inducing property.

Conclusions

We report a one pot autoclave process for the synthesis of 5-oxo proline and α-amino glutarimide from L-glutamine. Xenobiotic detoxifying property of α-amino glutarimide is also proposed.     

Reduced-order models for control of fluids using the eigensystem realization algorithm

As sensors and flow control actuators become smaller, cheaper, and more pervasive, the use of feedback control to manipulate the details of fluid flows becomes increasingly attractive. One of the challenges is to develop mathematical models that describe the fluid physics relevant to the task at hand, while neglecting irrelevant details of the flow in order to remain computationally tractable. A number of techniques are presently used to develop such reduced-order models, such as proper orthogonal decomposition (POD), and approximate snapshot-based balanced truncation, also known as balanced POD. Each method has its strengths and weaknesses: for instance, POD models can behave unpredictably and perform poorly, but they can be computed directly from experimental data; approximate balanced truncation often produces vastly superior models to POD, but requires data from adjoint simulations, and thus cannot be applied to experimental data. In this article, we show that using the Eigensystem Realization Algorithm (ERA) (Juang and Pappa, J Guid Control Dyn 8(5):620?C627, 1985) one can theoretically obtain exactly the same reduced-order models as by balanced POD. Moreover, the models can be obtained directly from experimental data, without the use of adjoint information. The algorithm can also substantially improve computational efficiency when forming reduced-order models from simulation data. If adjoint information is available, then balanced POD has some advantages over ERA: for instance, it produces modes that are useful for multiple purposes, and the method has been generalized to unstable systems. We also present a modified ERA procedure that produces modes without adjoint information, but for this procedure, the resulting models are not balanced, and do not perform as well in examples. We present a detailed comparison of the methods, and illustrate them on an example of the flow past an inclined flat plate at a low Reynolds number.     

Model for phase coexistence in phase transitions

We propose a general model for describing the phenomena of phase coexistence in relation to pressure induced phase transformations by means of the T–P distribution in statistical thermodynamics. Using the well‐known B1–B2 transition in NaCl as a prototype, we demonstrate how phase coexistence gives rise to the changes in the bulk modulus and the equation‐of‐state across the transition. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2004     

On the bremsstrahlung background correction to the high-energy Compton spectroscopy

methodology for bremsstrahlung (BS) background correction to extract a true Compton profile in high-energy Compton scattering experiments is presented. The BS background profiles for Hg, computed within the Born approximation, are estimated for different values of incident energy. It is seen for the first time that the BS background contribution in high-energy Compton profile experiments like those employing third generation synchrotron radiation sources comes out to be significant and non-linear. Further, it is found that the incorporation of BS correction in data reduction of such an experiment performed on Hg at 662 keV energy helps in reconciliation of theory and experiment.     

Assessing outcomes for dysphonic patients

This study was designed to evaluate a disease-specific outcome measure for patients with selected voice disorders and to relate this instrument to a standardized quality of life measurement. In addition, the study attempts to document the degree of handicap for dysphonia patients globally, between different vocal pathologies, and in comparison to other chronic diseases. In this prospective, observational study, 260 adult patients evaluated for alterations of voice completed a general quality of life measure (the Medical Outcomes Trust Short Form 36-Item[SF-36]) and a voice-specific instrument (Voice Handicap Index [VHI]) pretreatment.

The highest correlation was between the social functioning score of the SF-36and the total score of the VHI and the physical, emotional, and functional subscales (p < 0.001) of the VHI. Significant correlation was also obtained for the SF-36 domains mental health (p < 0.01), general health (p < 0.01), and role functioning emotional (p < 0.017) with the three VHI domains and the total VHI score. Patients had significantly lower scores than the general U.S. population in five of the eight domains of SF-36. Patients with vocal fold paralysis had the highest level of pretreatment disability as measured on both the VHI and SF-36 among voice patients. The patients with dysphonia had a lower level of physical functioning than the patients with chronic sinusitis (p < 0.01), reflecting a greater handicap. In addition, the dysphonia group had lower levels of social functioning than the angina (p < 0.01) and sciatica (p < 0.01) groups and a lower score for mental health than the angina group (p < 0.01).

The SF-36 correlates with the VHI in the domains of social functioning,mental health, and role functioning emotional. The baseline handicap for voice disorders represents a significant disability even in comparison to conditions such as angina pectoris, sciatica, and chronic sinusitis.     

Minimax linear programming problem

In this paper, we consider the following minimax linear programming problem: min z = max_{1 ≤ j ≤ n}{C_jX_j}, subject to Ax = g, x ≥ 0. It is well known that this problem can be transformed into a linear program by introducing n additional constraints. We note that these additional constraints can be considered implicitly by treating them as parametric upper bounds. Based on this approach we develop two algorithms: a parametric algorithm and a primal—dual algorithm. The parametric algorithm solves a linear programming problem with parametric upper bounds and the primal—dual algorithm solves a sequence of related dual feasible linear programming problems. Computation results are also presented, which indicate that both the algorithms are substantially faster than the simplex algorithm applied to the enlarged linear programming problem.     

Optical constants of copper in s-d model

A non-interacting s-d band model is used to evaluate ?₂(ω) in copper. The free electron approximation is used for electrons in s-band, while a simplified tight-binding scheme is used for the d-electrons. It is found that only d-bands with m = 0 contribute to optical transitions. The transition matrix elements are explicitly calculated. The calculated ?₂(ω) gives reasonable agreement with measured optical conductivity.     

Best Approximation on Convex Sets in Metric Linear Spaces

In this paper the concepts of strictly convex and uniformly convex normed linear spaces are extended to metric linear spaces. A relationship between strict convexity and uniform convexity is established. Some existence and uniqueness theorems on best approximation in metric linear spaces under different conditions are proved.     

Compton profile study of α-manganese

The results of a Compton profile study on polycrystallineα-Mn are reported. Our measurement are compared with theoretical results computed for different 3d-4s electron configurations within the RFA model. Best agreement between the measured and calculated values is found for 3d ^5·44s ^1·6 configuration. Theoretical Compton profile ofγ-Mn calculated using the same procedure is close to that for bcc phase with similar electron configurations.