Identification of a Novel Self-Sufficient Styrene Monooxygenase from Rhodococcus opacus 1CP.

Sequence analysis of a 9-kb genomic fragment of the actinobacterium Rhodococcus opacus 1CP led to identification of an open reading frame encoding a novel fusion protein, StyA2B, with a putative function in styrene metabolism via styrene oxide and phenylacetic acid. Gene cluster analysis indicated that the highly related fusion proteins of Nocardia farcinica IFM10152 and Arthrobacter aurescens TC1 are involved in a similar physiological process. Whereas 413 amino acids of the N terminus of StyA2B are highly similar to those of the oxygenases of two-component styrene monooxygenases (SMOs) from pseudomonads, the residual 160 amino acids of the C terminus show significant homology to the flavin reductases of these systems. Cloning and functional expression of His10-StyA2B revealed for the first time that the fusion protein does in fact catalyze two separate reactions. Strictly NADH-dependent reduction of flavins and highly enantioselective oxygenation of styrene to (S)-styrene oxide were shown. Inhibition studies and photometric analysis of recombinant StyA2B indicated the absence of tightly bound heme and flavin cofactors in this self-sufficient monooxygenase. StyA2B oxygenates a spectrum of aromatic compounds similar to those of two-component SMOs. However, the specific activities of the flavin-reducing and styrene-oxidizing functions of StyA2B are one to two orders of magnitude lower than those of StyA/StyB from Pseudomonas sp. strain VLB120

Electrochemical processes in a wire-in-a-capillary bulk-loaded, nano-electrospray emitter

AbstractExperiments are described that illustrate solvent oxidation, emitter electrode corrosion, and analyte oxidation in positive ion mode nano-electrospray mass spectrometry using a wire-in-a-capillary, bulk-loaded nano-electrospray emitter geometry. Time-lapsed color photography of pH and metal specific indicator solutions within operating nano-electrospray emitters, as well as temporal changes in the ions observed in the nano-electrospray mass spectra, are used to probe these reactions, judge their magnitude, and study the time dependent changes in solution composition and gas-phase ion signal brought about as a result of these electrochemical reactions. The significance of these observations for analytical applications of nano-electrospray mass spectrometry are discussed. (J Am Soc Spectrom 2001, 853–862) Published by Elsevier Science Inc

The combination of sibling victimization and parental child maltreatment on mental health problems and delinquency

This study examined how the combination of sibling victimization and parental child maltreatment is related to mental health problems and delinquency in childhood and adolescence. Co-occurrence, additive associations, and interactive associations of sibling victimization and parental child maltreatment were investigated using a sample of 2,053 children aged 5–17 years from the National Survey of Children’s Exposure to Violence. The results provide primarily evidence for additive associations and only suggest some co-occurrence and interactive associations of sibling victimization and child maltreatment. Evidence for co-occurrence was weak and, when controlling for the other type of maltreatment, only found for neglect. Sibling victimization was related to more mental health problems and delinquency over and above the effect of child abuse and neglect. Moderation by sibling victimization depended on child age and was only found for the relation between both types of child maltreatment by parents and delinquency. For mental health, no interactive associations were found. These results highlight the unique and combined associations between sibling victimization on child development.Development Psychopathology in context: famil

Automating Agential Reasoning: Proof-Calculi and Syntactic Decidability for STIT Logics

This work provides proof-search algorithms and automated counter-model extraction for a class of STIT logics. With this, we answer an open problem concerning syntactic decision procedures and cut-free calculi for STIT logics. A new class of cut-free complete labelled sequent calculi G3LdmL^m_n, for multi-agent STIT with at most n-many choices, is introduced. We refine the calculi G3LdmL^m_n through the use of propagation rules and demonstrate the admissibility of their structural rules, resulting in auxiliary calculi Ldm^m_nL. In the single-agent case, we show that the refined calculi Ldm^m_nL derive theorems within a restricted class of (forestlike) sequents, allowing us to provide proof-search algorithms that decide single-agent STIT logics. We prove that the proof-search algorithms are correct and terminate

Integrated systems for rapid point of care (PoC) blood cell analysis

Counting the different subpopulations of cells in a fingerprick of human blood is important for a number of clinical point-of-care (PoC) applications. It is a challenge to demonstrate the integration of sample preparation and detection techniques in a single platform. In this paper we demonstrate a generic microfluidic platform that combines sample processing and characterisation and enumeration in a single, integrated system. Results of microfluidic 3-part differential leukocyte (granulocyte, lymphocyte and monocyte) counts, together with erythrocyte and thrombocyte (platelet) counts, in human blood are shown and corroborated with results from hospital clinical laboratory analysis

No! Don't touch the toys:Preschoolers' discipline towards their younger siblings

Parental limit setting is a challenging and common situation in the daily lives of young children. During these situations, older siblings may use their more advanced cognitive skills and their greater physical strength to discipline their younger sibling and prevent or correct noncompliant behavior. This is the first study to examine preschoolers' discipline towards their toddler siblings during parental limit setting. In addition to observing preschoolers' sibling discipline, associations with their inhibitory control and externalizing behavior, their sibling's noncompliance and both children's gender were investigated. Sibling discipline was observed during parental limit setting in 285 families during one home visit with the mother and one home visit with the father. Preschoolers did discipline their younger siblings without being asked in the majority of the families, with girls displaying more disciplining behavior than boys. Toddlers' noncompliance was related to increased sibling discipline when their older siblings showed high levels of externalizing behavior themselves, although no such relation was found in case of older siblings with low levels of externalizing behavior. Sibling discipline was not related to preschoolers' inhibitory control or toddler's gender. Sibling discipline might thus be an expression of power assertion of the older sibling, instead of the moral urge to prevent transgressions. Highlights: Preschoolers' discipline towards their toddler siblings was examined during parental limit setting, as well as associations with characteristics of both children. Observed discipline towards a younger sibling was related to externalizing behavior and not to inhibitory control of the older sibling. Sibling discipline seems to be an expression of older siblings' power assertion, instead of a moral urge to prevent transgressions.</p