Thermal Stability of ε-Hexanitrohexaazaisowurtzitane in an Estane Formulation

A change in color and density during prolonged heating of a formulation containing ε-hexanitrohexaazaisowurtzitane (HNIW) and Estane 5702 was investigated by Fourier transform infrared (FTIR) spectroscopic analysis. Starting materials, virgin and final colored formulation were studied. Analysis revealed polymorphic impurity at all stages of production and processing, the nature and concentration of which changed with treatment of the material. Thermally-induced polymorphic conversion was determined to be the cause of the decrease in density, whereas the color change was speculated to be the result of binder degradation. Sensitivity to impact, friction and electrostatic spark were unchanged.     

Heat resistance in Escherichia coli and its implications on ground beef cooking recommendations in Canada

This study assessed the adequacy of the current cooking recommendations in relation to heat resistant Escherichia coli by evaluating eight potentially heat resistant E. coli strains (four generic and four E. coli O157:H7) along with AW1.7. The D_60°C-values for these strains varied from 1.3 to 9.0 min, with J3 and AW1.7 being the least and most heat resistant strains, respectively. The D_60°C-values for E. coli 62 and 68 were similar and were not affected by growth medium, while the heat resistance of C37, J3, and AW1.7 varied with the growth medium. When heated in extra lean ground beef (100 g) in vacuum pouches, the mean D_54°C, D_57°C, and D_60°C-values were 44.8, 18.6, and 2.9 min for C37, 13.8, 6.9, and 0.9 min for J3, and 40.5, 9.1, and 6.1 min for AW1.7. Burger temperatures continued to rise after being removed from heat when the target temperature was reached, by 3–5°C, and resting of 1 min would result in a destruction of 133, 374 and 14 log C37, J3 and AW1.7. These findings along with the very low occurrence of heat resistant E. coli expected in ground beef show that cooking ground beef to 71°C should be adequate.     

Interaction of n-3 long-chain polyunsaturated fatty acids with n-6 fatty acids in suckled rat pups

The addition of long-chain polyunsaturated fatty acids (LCP: C20, and C22) to infant formula may permit fatty acid accretion rates similar to breast-fed infants, and may have long-term outcome benefits, such as improved visual acuity and cognitive development. Although fish oil may provide a source of n-3 LCP, sources of n-6 LCP have been more difficult to identify. The present study evaluates the effects of n-3 and n-6 LCP derived from single-cell oils on liver, plasma, and brain fatty acid levels in a neonatal animal model. Newborn rat pups were suckled for 14 d by dams receiving diets containing n-3 LCP alone or combinations of n-3 LCP and increasing doses of linoleic acid (18∶2n−6) or arachidonic acid (20∶4n−6). Dietary groups received 2% n−3 LCP and 1, 2, or 5% of either 18∶2n−6 or 20∶4n−6. The 20∶4n−6 source also contained modest levels of 18∶2n−6. At the termination of the study, liver, plasma, and brain were obtained from the rat pups and the phospholipid fatty acid profiles determined. The results indicate complex interactions of n−3 and n−6 fatty acids. Groups receiving dietary 20∶4n−6 incorporated higher levels of n−6 LCP into tissues than did the groups receiving 18∶2n−6. The brain was relatively resistant to changes in fatty acid composition compared with the liver and plasma. As expected, tissue n−3 LCP levels were reciprocally related to n−6 levels. The present results document that single-cell LCP oils are bioavailable in a neonatal animal model. The use of 20∶4n−6 is a more effective means of supporting n−6 status than the use of 18∶2n−6. These results may have implications for the addition of LCP to infant formula.     

Direct Enzymatic Synthesis of a Deep-Blue Fluorescent Noncanonical Amino Acid from Azulene and Serine

We report a simple, one-step enzymatic synthesis of the blue fluorescent noncanonical amino acid β-(1-azulenyl)-l -alanine (AzAla). By using an engineered tryptophan synthase β-subunit (TrpB), stereochemically pure AzAla can be synthesized at scale starting from commercially available azulene and l -serine. Mutation of a universally conserved catalytic glutamate in the active site to glycine has only a modest effect on native activity with indole but abolishes activity on azulene, suggesting that this glutamate activates azulene for nucleophilic attack by stabilization of the aromatic ion.     

Randomized prevention trial for early conduct problems: Effects on proactive parenting and links to toddler disruptive behavior.

Despite knowledge of early pathways to conduct problems, few preventive interventions are specifically designed to modify disruptive behavior in toddlerhood. One potential prevention target is proactive and positive parenting, which is associated with reduced risk of conduct problems in preschoolers. This randomized trial with 120 low-income 2-year-old boys examined whether a brief family-centered intervention that reduces disruptive behavior (D. Shaw, T. Dishion, L. Supplee, F. Gardner, & K. Arnds, 2006) also leads to increases in proactive and positive parenting. It also explored whether change in parenting predicts change in disruptive behavior. In the intervention group, proactive and positive parenting skills increased among parents of 3-year-olds. Change in proactive and positive parenting of 2- to 3-year-old toddlers correlated with change in child disruptive behavior, although the mediation effect of positive parenting was of only borderline significance. Findings suggest that even within a brief and multifaceted preventive intervention, change in proactive parenting skills contributes modestly but significantly to change in child problem behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Antimicrobial peptides as new recognition molecules for screening challenging species

The goal of this study was to evaluate binding of four targets of biodefense interest to immobilized antimicrobial peptides (AMPs) in biosensor assays. Polymyxins B and E, melittin, cecropins A, B, and P, parasin, bactenecin and magainin-1, as well as control antibodies, were used as capture molecules for detection of Cy3-labeled Venezuelan equine encephalitis virus (VEE), vaccinia virus, C. burnetti and B. melitensis. Although VEE, vaccinia virus and C. burnetti did not show any binding activity to their corresponding capture antibodies, B. melitensis bound to immobilized anti-Brucella monoclonal antibodies. The majority of the immobilized AMPs included in this study bound labeled VEE, vaccinia virus and C. burnetti in a concentration-dependent manner, and B. melitensis bound to polymyxin B, polymyxin E, and bactenecin. No binding was observed on immobilized magainin-1. In contrast to all bacterial targets tested to date, VEE and vaccinia virus demonstrated similar patterns of binding to all peptides. While the direct assay is generally replaced by a sandwich assay for analysis of real-world samples, direct binding experiments are commonly used to characterize specificity and sensitivity of binding molecules. In this case, they clearly demonstrate the capability of AMPs as recognition molecules for four biothreat agents.     

Joint-attentional states and lexical acquisition at 18 months.

Two groups of 18-mo-old infants were observed during a relatively natural play session with an adult experimenter and several toys. A novel object associated with one of the toys was labeled a dodo by the experimenter using either an attention-following strategy (i.e., introducing the label when the infant was focused on the dodo object) or an attention-switching strategy (i.e., introducing the label when the infant was focused on an alternative object). With factors such as frequency of exposure to the object label and infant compliance equivalent across the groups, infants in the attention-following procedure were more likely to correctly identify the dodo object in a subsequent comprehension task. These experimental data corroborate previous correlational observations suggesting that early lexical development is facilitated during interactions in which the caregiver is following rather than leading the infant's focus of attention. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A note on universal composable zero-knowledge in the common reference string model

Pass observed that universal composable zero-knowledge (UCZK) protocols in the common reference string (CRS) model lose deniability that is a natural security property and implication of the ZK functionality in accordance with the UC framework. An open problem (or, natural query) raised in the literature is: are there any other essential security properties, other than the well-known deniability property, that could be lost by UCZK in the CRS model, in comparison with the ZK functionality in accordance with the UC framework? In this work, we answer this open question (or, natural query), by showing that when running concurrently with other protocols UCZK in the CRS model can lose proof of knowledge (POK) property that is very essential and core security implication of the ZK functionality. This is demonstrated by concrete attack against naturally existing UCZK protocols in the CRS model. Then, motivated by our attack, we make further clarifications of the underlying reasons beneath the concrete attack, and investigate the precise security guarantee of UC with CRS.