Connectomic markers of disease expression, genetic risk and resilience in bipolar disorder.

Bipolar disorder (BD) is characterized by emotional dysregulation and cognitive deficits associated with abnormal connectivity between subcortical-primarily emotional processing regions-and prefrontal regulatory areas. Given the significant contribution of genetic factors to BD, studies in unaffected first-degree relatives can identify neural mechanisms of genetic risk but also resilience, thus paving the way for preventive interventions. Dynamic causal modeling (DCM) and random-effects Bayesian model selection were used to define and assess connectomic phenotypes linked to facial affect processing and working memory in a demographically matched sample of first-degree relatives carefully selected for resilience (n=25), euthymic patients with BD (n=41) and unrelated healthy controls (n=46). During facial affect processing, patients and relatives showed similarly increased frontolimbic connectivity; resilient relatives, however, evidenced additional adaptive hyperconnectivity within the ventral visual stream. During working memory processing, patients displayed widespread hypoconnectivity within the corresponding network. In contrast, working memory network connectivity in resilient relatives was comparable to that of controls. Our results indicate that frontolimbic dysfunction during affect processing could represent a marker of genetic risk to BD, and diffuse hypoconnectivity within the working memory network a marker of disease expression. The association of hyperconnectivity within the affect-processing network with resilience to BD suggests adaptive plasticity that allows for compensatory changes and encourages further investigation of this phenotype in genetic and early intervention studies

What is behind a summary-evaluation decision?

Research in psychology has reported that, among the variety of possibilities for assessment methodologies, summary evaluation offers a particularly adequate context for inferring text comprehension and topic understanding. However, grades obtained in this methodology are hard to quantify objectively. Therefore, we carried out an empirical study to analyze the decisions underlying human summary-grading behavior. The task consisted of expert evaluation of summaries produced in critically relevant contexts of summarization development, and the resulting data were modeled by means of Bayesian networks using an application called Elvira, which allows for graphically observing the predictive power (if any) of the resultant variables. Thus, in this article, we analyzed summary-evaluation decision making in a computational framewor

Ammonium nitrate as an oxidizer in solid composite propellants

Despite the fact that ammonium nitrate (AN) has the highest hydrogen content and fairly high oxygen balance (compared to other oxidizers), its extremely low formation enthalpy and relatively low density makes it one of the worst power oxidizers in solid composite propellants (SCP). Nevertheless, AN has certain advantages − the combustion of the compositions containing AN is virtually safe, its combustion products are ecologically clean, it is very accessible and cheap, and also very thermostable (far more stable than ammonium dinitramide (ADN)). Besides, its low density stops being a disadvantage if the propellant has to be used in deep space and therefore, must be carried there with other rocket carriers. The low cost of AN may also become a serious advantage in the AN application even in lower stages of multistage space launchers as well as in one-stage space launchers with low mass fraction of the propellant. The main specific features relevant to the creation of AN-based SCPs with the optimal energetic characteristics are discussed. The use of metals and their hydrides and proper fuel-binders as well as the recent successes in phase stabilization of AN are described

The ways for development of environmentally safe solid composite propellants

The paper considers a wide set of issues concerning the creation of high energetic solid composite propellants causing the minimal polluting effect on the environment. Thereby, the level of toxicity of products of different compositions is discussed and propellants with perchlorates oxidizers are compared with propellants with halogen free oxidizers (mainly, ammonium dinitramide, HMX, CL-20). The main methods for creating compositions having a required performance and the highest energetic characteristics are also under discussion. The dependences of the specific impulse on the mode of formulation arrangement and on the compounds' properties (i.e., formation enthalpy, density, element content) are demonstrated. The main principles for the maximal use of energetic potential of chemical substances are under consideration. These are the proper selection of the binder type which would be optimal for the given mixture of oxidizer with fuel (or energetic) component and the opportunity of using metals and their hydrides (mainly, aluminum hydride (AH)). Main obstacles in using different kinds of compositions, as well as advantages of specific propellants are under consideration as well. A special attention is paid to the interrelationship between the energetic parameter and other performances (thermal stability, combustion law, sensitivity, and compatibility)

Prognosis of energetic compounds stability in solid phase

Results of the analysis and specification of phenomenological models of the monomolecular reactions running homogeneously in volume of undisturbed crystal lattice or localized on its defects are presented. It is shown, that within the limits of these models it is possible to calculate with satisfactory accuracy the ratio of rate constants in liquid and solid phases KT = kliq/ksol, and thus on known kliq to predict ksol, describing stability of substance

Ammonium nitrate phase state stabilization with small amounts of some organic compounds

The investigation considers phase stabilization of ammonium nitrate for considerable extension of its application area including new generation of gas-generating compositions for airbag inflators. It was shown that alloys of ammonium nitrate with small amounts (2-10%) of some organic compounds can have no phase transitions or at least have only one instead of three ones in initial ammonium nitrate. The mostly effective as stabilizers are the compounds that have rather close crystallographic parameters. A strong donor-acceptor interaction between nitrate-anion and organic molecules are found. Using quantum-chemical calculations, X-ray analysis, X-ray phase analysis, UV- and IR-spectroscopy it was found a new ammonium nitrate phase state in its alloy with some organic additives. This state is stable in temperature range between -50 and +100 C