Studying the effects of galactic cosmic radiation on astro- and microbiological model systems

In-depth knowledge regarding the biological effects of the radiation field in space is required for assessing the radiation risks in space. Within the last 50 years, space technology has provided tools for transporting terrestrial life beyond this protective magnetic field in order to study in situ responses to selected conditions of space (reviewed in Horneck et al., 2010). From a biological perspective applicable to simple and complex organisms (ranging from biomolecules and microorganisms to humans) various influential physical modifications such as increased radiation exposure were experienced onboard an orbiting spacecraft in low Earth orbit (LEO), out- and inside the International Space Station (ISS), orbiting Moon or on the way to other astrobiological-interesting targets (Mars or icy moons of Saturn or Jupiter). The majority of experiments on microorganisms in space were performed using Earth-orbiting robotic spacecraft, e.g., the Russian Foton satellites (FOTON) and the European Retrievable Carrier (EURECA), or human-tended spacecraft, such as space shuttles and space stations, e.g., MIR and ISS (reviewed in Nicholson, 2009; Nicholson et al., 2009; Horneck et al., 2010)

Mechanistic features of isomerizing alkoxycarbonylation of methyl oleate.

The weakly coordinated triflate complex [(P∧P)Pd(OTf)]+(OTf)− (1) (P∧ P = 1,3-bis(di-tert-butylphosphino) propane) is a suitable reactive precursor for mechanistic studies of the isomerizing alkoxcarbonylation of methyl oleate. Addition of CH3OH or CD3OD to 1 forms the hydride species [(P∧P)PdH(CH3OH)]+(OTf)− (2-CH3OH) or the deuteride [(P∧P)PdD(CD3OD)]+(OTf)− (2DCD3OD), respectively. Further reaction with pyridine cleanly affords the stable and isolable hydride [(P∧P)PdH- (pyridine)]+(OTf)− (2-pyr). This complex yields the hydride fragment free of methanol by abstraction of pyridine with BF3·OEt2, and thus provides an entry to mechanistic observations including intermediates reactive toward methanol. Exposure of methyl oleate (100 equiv) to 2D-CD3OD resulted in rapid isomerization to the thermodynamic isomer distribution, 94.3% of internal olefins, 5.5% of α,β-unsaturated ester and <0.2% of terminal olefin. Reaction of 2-pyr/BF3·OEt2 with a stoichiometric amount of 1-13C-labeled 1-octene at −80 °C yields a 50:50 mixture of the linear alkyls [(P∧P)Pd13CH2(CH2)6CH3]+ and [(P∧P)PdCH2(CH2)6 13CH3]+ (4a and 4b). Further reaction with 13CO yields the linear acyls [(P∧P)Pd13C(=O)12/13CH2(CH2)6 12/13CH3(L)]+ (5-L; L = solvent or 13CO). Reaction of 2-pyr/ BF3·OEt2 with a stoichiometric amount of methyl oleate at −80 °C also resulted in fast isomerization to form a linear alkyl species [(P∧P)PdCH2(CH2)16C(=O)OCH3]+ (6) and a branched alkyl stabilized by coordination of the ester carbonyl group as a four membered chelate [(P∧P)PdCH{(CH2)15CH3}C(=O)OCH3]+ (7). Addition of carbon monoxide (2.5 equiv) at −80 °C resulted in insertion to form the linear acyl carbonyl [(P∧P)PdC(=O)(CH2)17C(=O)OCH3(CO)]+ (8-CO) and the fivemembered chelate [(P∧P)PdC(=O)CH{(CH2)15CH3}C(=O)OCH3]+ (9). Exposure of 8-CO and 9 to 13CO at −50 °C results in gradual incorporation of the 13C label. Reversibility of 7 + CO ⇄ 9 is also evidenced by ΔG = −2.9 kcal mol−1 and ΔG‡ = 12.5 kcal mol−1 from DFT studies. Addition of methanol at −80 °C results in methanolysis of 8-L (L = solvent) to form the linear diester, 1,19-dimethylnonadecandioate, whereas 9 does not react and no branched diester is observed. DFT yields a barrier for methanolysis of ΔG‡ = 29.7 kcal mol−1 for the linear (8) vs ΔG‡ = 37.7 kcal mol−1 for the branched species (9)

Overcoming Cloud Concerns with Trusted Execution Environments? Exploring the Organizational Perception of a Novel Security Technology in Regulated Swiss Companies

Trusted execution environments are a new approach for isolating data, specific parts of code, or an entire application within untrusted cloud environments. This emerging security technology could also enable the migration to cloud infrastructures for organizations working with highly sensitive data. As current research does not address the organizational perception of trusted execution environments (TEEs), we conducted an explorative study to clarify the technological, environmental, and organizational views on this technology by health care, life sciences, and banking companies in Switzerland. The interview findings show that in these industries, missing technological knowledge as well as privacy and process regulation are perceived to be the most critical driver for organizational adoption of TEEs. The identified low intrinsic motivation to adopt novel technologies permits us to conclude that clarifying the regulatory impact of TEEs could drive future adoption by organizations

Density of states near the Mott-Hubbard transition in the limit of large dimensions

The zero temperature Mott-Hubbard transition as a function of the Coulomb repulsion U is investigated in the limit of large dimensions. The behavior of the density of states near the transition at U=U_c is analyzed in all orders of the skeleton expansion. It is shown that only two transition scenarios are consistent with the skeleton expansion for U<U_c: (i) The Mott-Hubbard transition is "discontinuous" in the sense that in the density of states finite spectral weight is redistributed at U_c. (ii) The transition occurs via a point at U=U_c where the system is neither a Fermi liquid nor an insulator.Comment: 4 pages, 1 figure; revised version accepted for publication in Phys. Rev. Let

The relationship between psychological characteristics of patients and their utilization of psychiatric inpatient treatment: A cross-sectional study, using machine learning

High utilizers (HU) are patients with an above-average use of psychiatric inpatient treatment. A precise characterization of this patient group is important when tailoring specific treatment approaches for them. While the current literature reports evidence of sociodemographic, and socio-clinical characteristics of HU, knowledge regarding their psychological characteristics is sparse. This study aimed to investigate the association between patients' psychological characteristics and their utilization of psychiatric inpatient treatment. Patients from the University Psychiatric Clinics (UPK) Basel diagnosed with schizophrenia spectrum or bipolar affective disorders participated in a survey at the end of their inpatient treatment stay. The survey included assessments of psychological characteristics such as quality of life, self-esteem, self-stigma, subjective experience and meaning of psychoses, insight into the disease, and patients' utilization of psychiatric inpatient treatment in the last 30 months. The outcome variables were two indicators of utilization of psychiatric inpatient treatment, viz. "utilization pattern" (defined as HU vs. Non-HU [NHU]) and "length of stay" (number of inpatient treatment days in the last 30 months). Statistical analyses included multiple regression models, the least absolute shrinkage and selection operator (lasso) method, and the random forest model. We included 112 inpatients, of which 50 were classified as HU and 62 as NHU. The low performance of all statistical models used after cross-validation suggests that none of the estimated psychological variables showed predictive accuracy and hence clinical relevance regarding these two outcomes. Results indicate no link between psychological characteristics and inpatient treatment utilization in patients diagnosed with schizophrenia spectrum or bipolar affective disorders. Thus, in this study, the examined psychological variables do not seem to play an important role in patients' use of psychiatric inpatient treatment; this highlights the need for additional research to further examine underlying mechanisms of high utilization of psychiatric inpatient treatment