Towards an anthrax detector using the femtosecond adaptive spectroscopic technique for coherent anti-Stokes Raman Spectroscopy: Coherent anti-Stokes Raman spectroscopy signal from dipicolinic acid in bacterial spores

Abstract

We present experimental evidence of a resonant coherent anti-Stokes Raman spectroscopy (CARS) signal from dipicolinic acid, a marker molecule in anthrax spores. We also show some evidence of resonant CARS signal associated with the 1000 cm^?1 resonance from Bacillus Globigii spores which are similar to anthrax spores. These results constitute a first step towards developing a rapid identification technique for bacterial spores.     

The Japanese Photographers of Broome: Photography and Cross-Cultural Encounter

The remote West Australian town of Broome has a unique photography heritage that sheds new light on the complexities of photography and intercultural relations. During the early twentieth century thriving Japanese communities were established in this region around the lucrative pearling industry. These Japanese communities also helped to develop a fascinating photography culture in Broome. Photography was not simply a business opportunity for the Japanese or a means of documenting people and events; it was a medium through which hierarchised social relations were produced, redefined, and challenged. This article examines photographs by these Japanese residents as an important site of cross-cultural communication and interpretation. These photographs of Anglo-Australian, Japanese, and Aboriginal residents of Broome enrich the study of cross-cultural photographic encounters, and emphasise the dynamic and dispersed qualities of Australian photographic practice and history. Here national histories of photography are usefully conceptualised as the products of imbricated social, economic, and cultural relations that operate across regional, national, and international realms.     

Modifying biodegradable plastics with additives based on condensed tannin esters

Condensed tannins derived from Pinus radiata bark have been esterified and added to biodegradable plastics as extrusion compounded functional plastic additives. The presence of longer alkyl chain hexanoate esters promoted tannin miscibility in the commercial polyesters Bionolle? and Biopol? whereas short chain acetate esters tended to remain as discrete domains, acting as fillers in the processed plastics. In the aliphatic polyester Bionolle the presence of tannin esters at typical plastic additive loadings did not alter plastic mechanical properties whereas at 5% content in Biopol the tannin‐additives reduced both flexural and tensile properties. Similarly tannin esters do not alter the melt or glass transition temperatures of the polyesters, but tannin hexanoate at 5% can influence the crystallization temperatures. Artificially aging plastics realized the functionality these plant extracts can impart to plastics in acting to reduce ultraviolet (UV)‐induced plastic degradation. Results indicate the tannin‐additives likely provide a stabilising role through inhibiting UV penetration into the plastic, with color analysis suggesting the tannin moiety itself was sacrificial and preferentially degrading. The imparted UV stability was linked to the dissolution of tannin esters in the plastic with longer chain esters providing greater protection against UV degradation. Tannin esters showed potential as functional additives for biodegradable polymers enhancing the UV stability of the plastic. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41626.     

Size-dependent deposition of inhaled nanoparticles in the rat respiratory tract using a new nose-only exposure system

Concerns about the potential health effects of exposure to nanomaterials have led to a growing number of in vivo inhalation toxicity studies using nanoparticle aerosols. Estimates of aerosol deposition within the respiratory tract are important for these studies to enable: (a) the interpretation of the results, in particular, the evaluation of dose–response relationships; (b) comparison with the results of other related studies; and (c) the extrapolation of results from animal models to human. Unfortunately, only a limited number of studies have been undertaken to investigate respiratory tract deposition efficiencies for nano-sized aerosol particles. This is of particular importance as deposition efficiencies are predicted to vary significantly over the nano-size range for some elements of the respiratory tract. In this study, female Wistar-Kyoto rats were exposed in a new design nose-only inhalation exposure system to spark generated radioactive iridium-192 nanoparticle aerosols of four particle sizes chosen to cover the majority of the nano-size range (nominal sizes: 10, 15, 35, and 75 nm). The content of iridium-192 in the lung, head, gastrointestinal tract, and various other organs and tissues was measured. Aerosol deposition efficiencies in the whole respiratory tract and components (head airways, lung, alveolar region, and tracheobronchial region) were estimated and compared with the predictions of the Multiple Path Particle Dosimetry (MPPD) model (v2.11). The experimentally derived deposition efficiencies were broadly consistent with, but typically higher than, model predictions and the results of comparable studies in the literature.

Copyright © 2016 American Association for Aerosol Research     

Investigation of carbon dioxide photoreduction process in a laboratory-scale photoreactor by computational fluid dynamic and reaction kinetic modeling

The production of solar fuels via the photoreduction of carbon dioxide to methane by titanium oxide is a promising process to control greenhouse gas emissions and provide alternative renewable fuels. Although several reaction mechanisms have been proposed, the detailed steps are still ambiguous, and the limiting factors are not well defined. To improve our understanding of the mechanisms of carbon dioxide photoreduction, a multiphysics model was developed using COMSOL. The novelty of this work is the computational fluid dynamic model combined with the novel carbon dioxide photoreduction intrinsic reaction kinetic model, which was built based on three-steps, namely gas adsorption, surface reactions and desorption, while the ultraviolet light intensity distribution was simulated by the Gaussian distribution model and Beer-Lambert model. The carbon dioxide photoreduction process conducted in a laboratory-scale reactor under different carbon dioxide and water moisture partial pressures was then modeled based on the intrinsic kinetic model. It was found that the simulation results for methane, carbon monoxide and hydrogen yield match the experiments in the concentration range of 10⁻⁴ mol·m^–3 at the low carbon dioxide and water moisture partial pressure. Finally, the factors of adsorption site concentration, adsorption equilibrium constant, ultraviolet light intensity and temperature were evaluated.     

PMMA composites of single‐walled carbon nanotubes‐graft‐PMMA

To facilitate the dispersion of single‐walled carbon nanotubes (SWCNT) into poly(methyl methacrylate) (PMMA), SWCNT were functionalized with a RAFT chain transfer agent, and PMMA was grafted from the SWCNT by reversible addition–fragmentation transfer (RAFT) polymerization to give SWCNT‐g‐PMMA containing 6 wt % PMMA. SWCNT‐g‐PMMA in the form of small bundles was dispersed into PMMA matrices. The SWCNT‐g‐PMMA filler increased the glass transition temperature (T_g) of the composite when the matrix molecular weight M_n was less than the graft molecular weight, but not when the matrix M_n was equal to or greater than the graft M_n. The threshold of electrical conductivity of the composites as a function of weight percent SWCNT increased from 0.2% when matrix M_n was less than graft M_n to about 1% when matrix M_n was greater than graft M_n. Dynamic mechanical analyses of the composites having graft M_n less than or equal to matrix M_n showed broader rubbery plateaus with increased SWCNT content but no significant differences between samples with different grafted PMMAs. The results indicate that lower M_n matrix wets the SWCNT‐g‐PMMA whereas higher M_n matrix does not wet the SWCNT‐g‐PMMA. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39884.     

Michael J. Mahoney: A retrospective.

Michael Mahoney, who made seminal contributions not only to the Society for the Exploration of Psychotherapy Integration (SEPI) but also to the entire field of psychotherapy, died a tragic death at the age of 60 on May 31, 2006. He published more than 250 scholarly articles and chapters, authored and edited 19 books (one of which was awarded a Citation Classic by the Science Citation Index), edited 4 journals, and served on 23 editorial boards plus numerous guest editorships and advisory boards. His research spanned a tremendous breadth without sacrificing depth. Primarily, however, he inquired into development across the life course, including but not limited to psychotherapy. Initially trained as a behaviorist, he played a significant role in the cognitive revolution in psychology; he was also a leading figure in constructivist psychotherapies. He was a Fellow of the World Academy of Art and Science, as well as a Fellow of the American Association for the Advancement of Science. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The short of it: Abbreviating the temporal discounting procedure.

A typical temporal discounting procedure determines the present, subjective value (indifference point) of a delayed outcome at 5 to 8 different delays to that outcome. These indifference points are used to determine a single index of discounting called a discounting rate. One concern that remains in the collection of this data is the high number of trials or choices, resulting in participant fatigue or other factors that may affect the validity of the data. In this report, we propose an abbreviated alternative to the more comprehensive and time-consuming discounting procedure. Specifically, we propose that fewer indifference points can be used to determine statistically equivalent discount rates with no loss in data sensitivity. We reanalyzed temporal discounting data obtained with 7 indifference points, and estimated discount rates from all combinations of 2, 3, and 4 of the 7 indifference points. Results indicate that valid and sensitive discounting indices can be obtained with fewer indifference points, and the most appropriate sets of indifference points are highlighted. The proposed abbreviated procedure is likely to be particularly useful when time constraints or participant fatigue is a concern as well as in repeated-measures contexts. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A history of numerical modelling of the Wairakei geothermal field

The history of computer modelling of the Wairakei geothermal field is reviewed. It covers the development of lumped-parameter models during the 1970s and then discusses the evolution and first applications of geothermal reservoir simulation techniques. The development of reservoir models of Wairakei at the University of Auckland began in the early 1980s; current models produces good matches against field data. Many future scenarios have been run using the University's models and have been presented at various regulatory hearings. The general conclusion from these scenarios is that Wairakei can continue producing electricity at the current level for at least another 50 years, and if Wairakei is shut down after 100 years of operation it will recover to its pre-exploitation state after a further 300 years.     

Novel models of intertemporal valuation: Past and future outcomes.

Temporal discounting refers to the reduction in the present subjective value of an outcome as a function of the temporal distance to that outcome. Though a number of mathematical models have been proposed to describe this time/value relationship, this search has largely excluded insights from the literature on memory decay. This study examines the utility of memory decay models by comparing the fits of 4 of these models to fits from established temporal discounting models using past and future temporal discounting data. These results (a) suggest that a single model describes valuation of both future and past outcomes; (b) indicate the exponential-power model, from memory decay literature, is statistically superior in fitting discounting data from both past and future outcomes; and (c) support the advancing perspective of the psychological interconnectedness of the future and past. (PsycINFO Database Record (c) 2010 APA, all rights reserved)