High-speed high-resolution gas-phase Raman spectroscopy

A new Raman spectrometer has been developed that can produce a complete high-resolution gas-phase vibrational spectrum during the time period of a single laser pulse. Conventional gas-phase Raman spectroscopy uses a single narrow-band laser to produce signals that are weak, requiring relatively long collection times. This spectrometer uses a degenerate OPO as a broad-band source that covers a continuous range of >3000 cm(-1). When a beam from this broad-band source is added to a narrow-band laser beam, the intensity of the Raman signal is amplified by the nonlinear optical effect. The resulting instrument can generate spectra with high-spectral (<1 cm(-1)), spatial (<0.05 mm2), and temporal resolution (<1 s).     

When choice is demotivating: Can one desire too much of a good thing?

Current psychological theory and research affirm the positive affective and motivational consequences of having personal choice. These findings have led to the popular notion that the more choice, the better—that the human ability to manage, and the human desire for, choice is unlimited. Findings from 3 experimental studies starkly challenge this implicit assumption that having more choices is necessarily more intrinsically motivating than having fewer. These experiments, which were conducted in both field and laboratory settings, show that people are more likely to purchase gourmet jams or chocolates or to undertake optional class essay assignments when offered a limited array of 6 choices rather than a more extensive array of 24 or 30 choices. Moreover, participants actually reported greater subsequent satisfaction with their selections and wrote better essays when their original set of options had been limited. Implications for future research are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

University science students' knowledge of fats.

PURPOSE: Students entering university often lack knowledge about fats; whether students gain such information during four years at university is unclear. Students' knowledge of fat in the first and fourth years was measured and compared. The effect of a nutrition course on knowledge was also examined. METHODS: A total of 215 science students at a small undergraduate university completed a 15-item, closed-ended questionnaire concerning knowledge of fats in the diet. RESULTS: Fourth-year science students have greater nutrition knowledge of fats than do first-year science students (p<0.005). Given that the majority of first-year students reside on campus and the majority of fourth-year students reside off campus, the purchasing of food and preparation of meals may explain the senior students' greater knowledge of fat. Students who have taken a nutrition course know more about fats than do those who have not (p<0.001). CONCLUSIONS: Taking even one course in nutrition greatly increases nutrition knowledge. Universities could encourage undergraduate students to take a basic nutrition course, which should emphasize the identification and understanding of different types of dietary fats.     

A Structure−Activity Relationship Study of Novel Hydroxamic Acid Inhibitors around the S1 Subsite of Human Aminopeptidase N

Aminopeptidase N (APN/CD13) is a zinc-dependent ubiquitous transmembrane ectoenzyme that is widely present in different types of cells. APN is one of the most extensively studied metalloaminopeptidases as an anti-cancer target due to its significant role in the regulation of metastasis and angiogenesis. Previously, we identified a potent and selective APN inhibitor, N-(2-(Hydroxyamino)-2-oxo-1-(3′,4′,5′-trifluoro-[1,1′-biphenyl]-4-yl)ethyl)-4-(methylsulfonamido)benzamide ( 3 ). Herein, we report the further modifications performed to explore SAR around the S1 subsite of APN and to improve the physicochemical properties. A series of hydroxamic acid analogues were synthesised, and the pharmacological activities were evaluated in vitro. N-(1-(3′-Fluoro-[1,1′-biphenyl]-4-yl)-2-(hydroxyamino)-2-oxoethyl)-4-(methylsulfonamido)benzamide ( 6 f ) was found to display an extremely potent inhibitory activity in the sub-nanomolar range.     

Structural insights into peptide self-assembly using photo-induced crosslinking experiments and discontinuous molecular dynamics

Determining the structure of the (oligomeric) intermediates that form during the self-assembly of amyloidogenic peptides is challenging because of their heterogeneous and dynamic nature. Thus, there is need for methodology to analyze the underlying molecular structure of these transient species. In this work, a combination of fluorescence quenching, photo-induced crosslinking (PIC) and molecular dynamics simulation was used to study the assembly of a synthetic amyloid-forming peptide, Aβ_16-22. A PIC amino acid containing a trifluormethyldiazirine (TFMD) group—Fmoc(TFMD)Phe—was incorporated into the sequence (Aβ*_16–22). Electrospray ionization ion-mobility spectrometry mass-spectrometry (ESI-IMS-MS) analysis of the PIC products confirmed that Aβ*_16–22 forms assemblies with the monomers arranged as anti-parallel, in-register β-strands at all time points during the aggregation assay. The assembly process was also monitored separately using fluorescence quenching to profile the fibril assembly reaction. The molecular picture resulting from discontinuous molecule dynamics simulations showed that Aβ_16-22 assembles through a single-step nucleation into a β-sheet fibril in agreement with these experimental observations. This study provides detailed structural insights into the Aβ_16-22 self-assembly processes, paving the way to explore the self-assembly mechanism of larger, more complex peptides, including those whose aggregation is responsible for human disease.     

The reuse of machining knowledge to improve designer awareness through the configuration of knowledge libraries in PLM

The nature of competition induces the need to constantly improve and perform better. For global aerospace manufacturers, this is as timely an epithet as ever as market forces urge for more growth, better financial return and market position. The macroeconomic aspect is compounded by the growth of product complexity and the need for higher product quality, hence the drive to reduce waste places emphasis upon production costs and the need to improve product performance. This paper focuses upon a rapid development and deployment method that enables the capture and representation of machining knowledge so that it may be shared and reused by design engineers to accelerate the design-make process. The study and mapping of information and knowledge relationships are described and put forward as a lightweight ontology. From this, a set of knowledge document templates were created to facilitate the capture, structuring and sharing of machining knowledge within a collaborative multidisciplinary aerospace engineering environment. An experimental pilot system has been developed to test and demonstrate that knowledge document templates can accelerate the sharing of machining knowledge within an industrial product lifecycle management environment. The results are discussed to provide a case for further development and application within the product domain.     

Spatial distribution of lead in human primary teeth as a biomarker of pre- and neonatal lead exposure

Lead remains one of the most hazardous toxins in our environment. Because the toxic effects of lead are most prominent during early development, it is important to develop a suitable biomarker for lead exposure during the pre- and neonatal periods. In the present study, the spatial distribution of lead was measured in the enamel and dentine of ten human primary teeth using laser ablation-inductively coupled plasma-mass spectrometry. The neonatal line, visualized using confocal laser scanning microscopy, was used to demarcate the pre- and postnatal regions of the sample teeth. Lead levels in pre- and postnatally formed enamel and dentine were compared to blood-lead levels measured at birth and one year of age for four of these participants. Mean dentine-lead levels ranged from 0.17+/-0.02 to 5.60+/-1.79 microg/g, and mean enamel-lead levels ranged from 0.04+/-0.01 to 1.47+/-0.20 microg/g. The results of this preliminary study showed that the spatial distribution of lead in dentine reflected the blood-lead levels. The present study demonstrates a methodology where the spatial distribution of lead in the dentine of human primary teeth may be used to obtain temporal information of environmental lead exposure during the pre- and neonatal periods.     

Stakeholder management in IOS projects: analysis of an attempt to implement an electronic patient file

Implementing an inter-organizational system (IOS) requires significant organizational as well as technical changes. These will affect stakeholders (upon whom promoters depend) with varying degrees of power and with varying degrees of interest in the system. Identifying stakeholders and understanding the sources of their attitudes will enable promoters to meet their expectations more fully, and hence encourage acceptance. We examine these issues through a theoretically based study of an attempt to introduce an Electronic Patient File system in The Netherlands. All saw that the system would benefit patients, yet powerful players resisted its implementation, fearing it would affect their interests. This paper develops and tests a model of stakeholder management, showing that those with high interest in the system lacked the power to implement it, while those with low interest had the power to block it. These negative attitudes were shaped by concerns not about the system itself, but about the likely effects on working routines, power, culture and finance. This paper implies that those promoting an IOS (in any sector) should, from the outset of a project, identify their power sources and seek to reconcile stakeholder interests.     

Eye-movement measurement techniques.

Evaluates the advantages and disadvantages of major eye-movement measurement techniques, including electrooculography; corneal reflection; limbus, pupil, and eyelid tracking; contact lens method; point-of-regard measurement; and double Purkinje image methods. A comparison of the technical aspects of all the methods is presented in table form. (42 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)