High Performance Steel: Research Front—Historical Account of Research Activities

This paper provides a summary of the major research studies conducted or being conducted in the U.S., to address design issues related to use of high performance steel (HPS) in bridge construction. Emphasis of the paper is on the work related to HPS-485W steel, which has specified minimum yield strength of 485 MPa (70 ksi). Design issues that are addressed in this paper include (1) flexural capacity of compact and noncompact HPS sections in negative bending; (2) issues related to ductility of HPS composite girders in the positive sections (this section presents a simplified ductility check for composite plate girders); (3) tensile ductility of HPS plates; (4) shear capacity of the hybrid steel plate girders; (5) live load deflections; and (6) brief overview of the work that is underway to develop innovative bridge configurations capable of incorporating the advantages of HPS.     

Is an attributional analysis of the learned helplessness phenomenon viable? A critique of the Abramson-Seligman-Teasdale reformulation.

Considers that the reformulation of the learned helplessness model by L. Y. Abramson et al (see record 1979-00305-001) overcomes many of the shortcomings inherent in the original model and raises questions for future research on helplessness and depression. A critique is made of the various components of the reformulated model: (a) Some questions are raised about the importance of attributions in predicting reactions to uncontrollable outcomes, including whether people make attributions and whether there is a relationship between attributions and behavior. (b) It is questioned whether the dimensions of attribution selected by Abramson et al are the most significant ones in predicting the nature and magnitude of behavioral deficits. (c) The possibility is raised that factors other than attributions and expectations for future control may influence reactions to uncontrollable outcomes. Certain characteristics of the outcome, such as whether it is expected and whether people are able to find meaning in it, may be important. (d) The account of the cognitive, motivational, and affective responses to lack of control is examined. The present authors feel that 2 basic questions are left unanswered: What is the relationship between the various deficits that are proposed, and when does exposure to lack of control result in deficits, and when does it result in facilitated performance? (e) The reformulated learned helplessness model of depression is examined. The model is seen to raise questions about the direction of causality between attributions, expectations, and depression. (53 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Teaching sustainable design in architecture education: Critical review of Easy Approach for Sustainable and Environmental Design (EASED)

In the current context of climate change and ecological awareness, designing sustainable environments is definitely understood as a shared responsibility. With the construction sector consuming half of the world׳s energy, the role of some key stakeholders such as architects becomes even more critical when providing responsible and relevant design for the built environment. Thus, improving the way our environments are being designed challenges some cultural systems that show evident limits, such as the training of future architects and engineers.In this research, the focus is on architecture students and aims to demonstrate how the use of a new sustainable performance simulation tool, called Easy Approach for Sustainable and Environmental Design (EASED) could contribute to educate them about innovatively sustainable design. This was assessed through the evaluation of student engagement, their use of the tool and its appropriation. Results show that individual work was not convincing, whereas success was met during group work. Limits and improvement possibilities were found in the interface of EASED as well as in the educational set up of the tool.     

Ursolic acid analogues: non-phenolic functional food components in Jamaican raspberry fruits

The Rubus genus produces numerous species that are known for their medicinal properties. Rubus rosifolius, called the red raspberry, grows wild in elevated regions in Jamaica. Phytochemical examination of the ethyl acetate extract of the fruit yielded eight compounds of the 19-α-hydroxyursane type: euscaphic acid (1), 1-β-hydroxyeuscaphic acid (2), hyptatic acid B (3), 19α-hydroxyasiatic acid (4), trachelosperogenin (5), 4-epi-nigaichigoside F1 (6), nigaichigoside F1 (7), and trachelosperoside B-1 (8), as confirmed by NMR spectroscopy. Inhibition of cell proliferation by these compounds were determined by using MCF-7 (breast), SF-268 (CNS), NCI H460 (lung), HCT-116 (colon) and AGS (gastric) human tumour cells. Among the human tumour cell lines assayed, only compounds 3 and 6 displayed significant growth inhibition and was specific to colon tumour cells by 56% and 40%, respectively. These ursolic acid analogues were also tested for anti-inflammatory activity using in vitro cycloxegenase-1 (COX-1) and cycloxegenase-2 (COX-2) enzyme inhibitory assays. Compounds 1, 2 and 3 showed selective COX-1 enzyme inhibitory activity (13%, 25% and 35%) at 25 μg/ml. In the lipid peroxidation (LPO) inhibitory assays, compounds 2, 4, 7 and 6 inhibited LPO by 62%, 60%, 53% and 68%, respectively, at 25 μg/ml.     

As the number falls,alternatives to the Hagberg–Perten falling number method: A review

This review examines the application, limitations, and potential alternatives to the Hagberg–Perten falling number (FN) method used in the global wheat industry for detecting the risk of poor end-product quality mainly due to starch degradation by the enzyme α-amylase. By viscometry, the FN test indirectly detects the presence of α-amylase, the primary enzyme that digests starch. Elevated α-amylase results in low FN and damages wheat product quality resulting in cakes that fall, and sticky bread and noodles. Low FN can occur from preharvest sprouting (PHS) and late maturity α-amylase (LMA). Moist or rainy conditions before harvest cause PHS on the mother plant. Continuously cool or fluctuating temperatures during the grain filling stage cause LMA. Due to the expression of additional hydrolytic enzymes, PHS has a stronger negative impact than LMA. Wheat grain with low FN/high α-amylase results in serious losses for farmers, traders, millers, and bakers worldwide. Although blending of low FN grain with sound wheat may be used as a means of moving affected grain through the marketplace, care must be taken to avoid grain lots from falling below contract-specified FN. A large amount of sound wheat can be ruined if mixed with a small amount of sprouted wheat. The FN method is widely employed to detect α-amylase after harvest. However, it has several limitations, including sampling variability, high cost, labor intensiveness, the destructive nature of the test, and an inability to differentiate between LMA and PHS. Faster, cheaper, and more accurate alternatives could improve breeding for resistance to PHS and LMA and could preserve the value of wheat grain by avoiding inadvertent mixing of high- and low-FN grain by enabling testing at more stages of the value stream including at harvest, delivery, transport, storage, and milling. Alternatives to the FN method explored here include the Rapid Visco Analyzer, enzyme assays, immunoassays, near-infrared spectroscopy, and hyperspectral imaging.     

The Incorporation of Curcuminoids in Gamma-Cyclodextrins Improves Their Poor Bioaccessibility,Which Is due to Both Their Very Low Incorporation into Mixed Micelles and Their Partial Adsorption on Food

Scope

Turmeric curcuminoids mainly consist of curcumin (CUR), demethoxycurcumin (dCUR), and bisdemethoxycurcumin (bdCUR). CUR displays low bioavailability, partly due to poor solubilization in the intestinal lumen during digestion, while data for dCUR and bdCUR are scarce. The study aims to investigate the bioaccessibility of curcuminoids from turmeric extracts or from gamma-cyclodextrins, considering potential interactions with food.

Methods and results

Using an in vitro digestion model (correlation with CUR bioavailability: r = 0.99), the study shows that curcuminoid bioaccessibility from turmeric extract without food is low: bdCUR (11.5 ± 0.6%) > dCUR (1.8 ± 0.1%) > CUR (0.8 ± 0.1%). Curcuminoids incorporated into gamma-cyclodextrins display higher bioaccessibilities (bdCUR: 21.1 ± 1.6%; dCUR: 14.3 ± 0.9%; CUR: 11.9 ± 0.7%). Curcuminoid bioaccessibility is highest without food (turmeric extract: 2.0 ± 0.1%; gamma-cyclodextrins: 12.4 ± 0.8%) and decreases with a meat- and potato-based meal (turmeric extract: 1.1 ± 0.2%; gamma-cyclodextrins: 2.4 ± 0.3%) or a wheat-based meal (turmeric extract: 0.1 ± 0.0%; gamma-cyclodextrins: 0.3 ± 0.1%). Curcuminoids exhibit low (<10%) incorporation efficiencies into synthetic mixed micelles (bdCUR > dCUR > CUR).

Conclusions

bdCUR and dCUR show greater bioaccessibilities versus CUR. Food diminishes curcuminoid bioaccessibility, likely by adsorption mechanisms. Gamma-cyclodextrins improve curcuminoid bioaccessibility.     

Sensory and physicochemical evolution of tropical cooked peeled shrimp inoculated by Brochothrix thermosphacta and Lactococcus piscium CNCM I-4031 during storage at 8°C

This study investigated the sensory quality and physicochemical evolution (pH, glucose, l-lactic acid, biogenic amine, free amino-acids and volatile compounds) during storage at 8 °C of cooked peeled shrimp inoculated with the specific spoilage bacteria Brochothrix thermosphacta alone or mixed with the protective strain Lactococcus piscium CNCM I-4031. Growth of both bacteria was monitored at regular intervals during storage by microbial counts and the thermal temperature gradient gel electrophoresis (TTGE) technique. Bacterial counts showed that L. piscium and B. thermosphacta inoculated at 7 log CFU/g and 3 log CFU/g were well adapted to shrimp, reaching a maximum level of 9 log CFU/g after 4 days and 10 days respectively. In mixed culture, the growth of B. thermosphacta was reduced by 3.2 ± 0.1 log CFU/g. The TTGE technique allowed monitoring the colonisation of the strains on the shrimp matrix and confirming the dominance of L. piscium in mixed culture throughout the experiment. Sensory analysis confirmed that B. thermosphacta spoiled the product after 11 days, when its cell number attained 8 log CFU/g with the emission of strong butter/caramel off-odours. This sensory profile could be linked to the production of 2,3 butanedione, cyclopentanol, 3-methylbutanol, 3-methylbutanal, 2-methylbutanal, 4-methyl-3-chloro-3-pentanol and ethanol, which were produced in more significant quantities in the B. thermosphacta batch than in the batches in which the protective strain was present. On the contrary, TVBN and TMA were not suitable as quality indicators for B. thermosphacta spoilage activity. In the products where the protective L. piscium strain was present, no adverse effect on sensory quality was noted by the sensory panels. Moreover, biogenic amine assessment did not show any histamine or tyramine production by this strain, underlining its safety profile. Both strains produced lactic acid (1850 mg/kg in L. piscium and B. thermosphacta batch on days 3 and 10 respectively; 3830 mg/kg on day 7 in mixed culture) and the pH decrease from 6.6 ± 0.0 to 5.9 ± 0.1 was similar in all batches. Lactic acid production or competition for free amino-acid was not involved in the inhibition mechanism; however rapid glucose consumption by L. piscium could partially explain the growth limitation of the spoilage micro-organism. This study demonstrated the spoilage characteristic of B. thermosphacta and the usefulness of L. piscium as a bioprotective culture for tropical cooked peeled shrimp without any adverse effect on the sensory quality of the product.     

Structural Elucidation of a Nonpeptidic Inhibitor Specific for the Human Immunoproteasome

Selective inhibition of the immunoproteasome is a promising approach towards the development of immunomodulatory drugs. Recently, a class of substituted thiazole compounds that combine a nonpeptidic scaffold with the absence of an electrophile was reported in a patent. Here, we investigated the mode of action of the lead compound by using a sophisticated chimeric yeast model of the human immunoproteasome for structural studies. The inhibitor adopts a unique orientation perpendicular to the β5i substrate‐binding channel. Distinct interactions between the inhibitor and the subpockets of the human immunoproteasome account for its isotype selectivity.     

A new in situ chemical reactor for studying heterogeneous catalysis by NMR: The GRASSHopper

A new device/technique, Gas Reactor And Solid Sample Hopper designated GRASSHopper II, is described as an alternative to magic-angle spinning (MAS) for in situ NMR experiments on reacting heterogeneous systems. It is capable of supporting NMR studies of heterogeneous catalysis in the batch mode, in the flow reactor mode and for measurements of chemical kinetics. This new approach is based on the technique of magic-angle hopping (MAH). Characteristics, advantages, limitations and potential areas of application are described. Preliminary results are shown on the formation, subsequent hydrolysis and then regeneration (via dehydration) of (C₆H₅)₃C⁺ carbocations in zeolite HY cavities, and on the gas–solid polymerization of ethylene on a Cp₂ZrCl₂/MAO/SiO₂ ‘supported' catalyst.