Design strategies to simplify and miniaturize imaging systems

We present the range of optical architectures for imaging systems based on a single optical component, an aperture stop, and a detector. Thanks to the formalism of third-order Seidel aberrations, several strategies of simplification and miniaturization of optical systems are examined. Figures of merit are also introduced to assess the basic optical properties and performance capabilities of such systems; by this way, we show the necessary trade-off between simplicity, miniaturization, and optical performance.     

Field Trials of Low-cost Reactive Media for the Passive Treatment of Circum-neutral Metal Mine Drainage in Mid-Wales,UK

This paper addresses the ability of five low-cost reactive materials to remove Zn, Pb, and Cd from Fe-poor, circum-neutral pH metal mine water in Mid-Wales, UK. Compost, fly ash, waste shell material, iron ochre, and a mixture of blast furnace slag (BFS) and basic oxygen furnace slag (BOS) were used in a series of small-scale passive treatment cells to assess metal removal from mine drainage initially containing, on average, 23.5 mg/L Zn, 0.5 mg/L Pb, and 0.05 mg/L Cd. Trial treatment cells contained between 1.5 and 12 kg of reactive media, had a 15 min residence time, and treated a discharge of up to 1 L per minute. Fly ash from a peat-fired power station was found to be the most effective material for metal removal, with concentrations reduced to 0.02 mg/L Zn, 0.0069 mg/L Pb, and 0.0001 mg/L Cd from over 1,000 L of water (between 98.6 and 99.9% removal). The other materials initially achieved high levels of metal removal (between 75 and 99.9% Zn, Pb, and Cd removed); however, all of the materials were saturated with Zn after less than 200 L of water had been treated. Metal sorption ranged from 21.4 mg/g Zn for the peat fly ash to 0.0015 mg/g Cd for the compost and BOS/BFS slag. The results of the pilot-scale field trials can be scaled to demonstrate that a modest-sized fly ash treatment cell (2.6 × 2.6 × 1 m) in size would be sufficient to remove 90% of the total metal load (Pb, Zn, and Cd) from this 10 L/min mine water discharge for a 1 year period. Importantly this research demonstrates that passive treatment for metal mine drainage can comply with water quality directives but cannot be considered a ‘walk-away’ solution; it requires modest (potentially annual) maintenance.     

TRANSMITTANCE OF NEAR-INRARED ENERGY BY BINARY GLASSES*

A study has been made of the transmittance of near-infrared energy by a number of binary glasses. Of the systems studied, the lithia-silica and lead oxide-silica glasses were found to have the highest transmittance of energy in the range of wave lengths from 3.0 to 5.0 microns. The transmittance of lithia-silica glass is compared with that of the other alkali-silica glasses. Values of transmittance are given for lead silicate glasses of higher lead content than previously reported in the literature.     

Mass Spectrometry,Ion Mobility Separation and Molecular Modelling: A Powerful Combination for the Structural Characterisation of Substituted Cyclodextrins Mixtures

When working on the synthesis of substituted cyclodextrins (CDs), the main challenge remains the analysis of the reaction media content. Our objective in this study was to fully characterise a complex isomers mixture of Lipidyl-βCDs (LipβCD) obtained with a degree of substitution 1 (DS = 1) from a one-step synthesis pathway. The benefit of tandem mass spectrometry (MS/MS) and ion mobility separation hyphenated with mass spectrometry (IM-MS) was investigated. The MS/MS fragment ion‘s relative intensities were analysed by principal component analysis (PCA) to discriminate isomers. The arrival time distribution (ATD) of each isomer was recorded using a travelling wave ion mobility (TWIM) cell allowing the determination of their respective experimental collision cross section (CCS_exp). The comparison with the predicted theoretical CCS (CCS_th) obtained from theoretical calculations propose a regioisomer assignment according to the βCD hydroxyl position (2, 3, or 6) involved in the reaction. These results were validated by extensive NMR structural analyses of pure isomers combined with molecular dynamics simulations. This innovative approach seems to be a promising tool to elucidate complex isomer mixtures such as substituted cyclodextrin derivatives.     

Isolation and characterization of a psychrotolerant toxin producer, Bacillus weihenstephanensis, in liquid egg products

A psychrotolerant bacteria of the Bacillus cereus group was found responsible for the spoilage of whole liquid egg products. By sequencing a 16S rRNA region and performing a PCR amplification of specific 16S rRNA and cspA signatures, a Bacillus weihenstephanensis was identified. Characterization of this strain shows its ability to grow in defined medium as well as in whole liquid egg at refrigerated temperatures. The strain isolated possesses genes encoding for hemolysin BL, nonhemolytic enterotoxin, and B. cereus enterotoxins and produces enterotoxins with cytotoxic activity in whole liquid egg, even at refrigerated temperatures. The isolate exhibits a clear ability to stick and form biofilms on stainless steel, the most common material used in egg breaking factories, as well as on model hydrophilic (glass) and hydrophobic (polytetrafluoroethylene) materials. These findings show the necessity to monitor for Bacillus contamination in egg products that are often used in the composition of particularly susceptible finished products such as cream, dessert, dairy, meat, and seafood.     

Asymptotic performances of a constructive algorithm

We present a numerical study of a neural tree learning algorithm, the “triolearning≓ strategy. We study the behaviour of the algorithm as a function of the size of the training set. The results show that a limited number of examples can be used to estimate both the network performance and the network complexity that would result from running the algorithm on a large data set.     

Effects of information processing load in abstinent and nonabstinent smokers' psychomotor task performance.

Recent evidence has indicated that nicotine, the active agent in tobacco, may affect mental abilities of smokers. To better understand the effects of nicotine on central processing, we used a basic chronometric approach to studying information processing. This chronometric approach allowed for the independent examination of nicotine's effects on two theoretically nonoverlapping information-processing stages, stimulus identification and response programming. Two stimulus intensity and four distance traversed conditions were used to affect the stimulus identification and response programming stages, respectively. The 11 subjects completed two experimental sessions (nicotinized and denicotinized), which were conducted 1 week apart. Each experimental session comprised two tests. The first test consisted of abstinent baseline measures, and the second test was administered after subjects smoked an investigator-supplied nicotinized or denicotinized cigarette. Data analysis revealed that the higher intensity stimulus elicited faster reaction times, as did the shorter movement distances, thus confirming successful manipulation of both the stimulus identification and response programming stages of the information-processing model. Furthermore, the significant improvement in reaction-time performance over baseline abstinent levels was consistent despite the manipulations made within the stimulus identification stage of processing, demonstrating that no interaction existed between stimulus intensity and the administration of nicotine. Interestingly, these data provide initial evidence that although nicotine may not affect the programming of very simple movements, it has a more pronounced effect on more complex movements. Although distance traversed had a reliable effect on movement time, nicotine had no observable effect.     

Identification and characterization of a novel member of the fibroblast growth factor family

A new member of the fibroblast growth factor (FGF) family, FGF-13, has been molecularly cloned as a result of high throughput sequencing of a human ovarian cancer cell library. The open reading frame of the novel human gene (1419 bp) encodes for a protein of 216 a.a. with a molecular weight of 22 kDa. The FGF-13 sequence contains an amino-terminal hydrophobic region of 23 a.a. characteristic of a signal secretion sequence. FGF-13 is most homologous, 70% similarity at the amino acid level, to FGF-8. Northern hybridization analysis demonstrated prominent expression of FGF-13 in human foetal and adult brain, particularly in the cerebellum and cortex. In proliferation studies with BaF3 cells, FGF-13 preferentially activates cell clones expressing either FGF receptor variant, 3-IIIc or 4. The signal transduction pathways of FGF-13 and FGF-2 were compared in rat hippocampal astrocytes. The two FGFs induce an equivalent level of tyrosine phosphorylation of mitogen-activated protein kinase (MAPK) and c-raf activation. However, FGF-13 is more effective than FGF-2 in inducing the phosphorylation of phospholipase C-gamma (PLC-gamma). Treatment of neuronal cultures from rat embryonic cortex with FGF-13 increases the number of glutamic acid decarboxylase immunopositive neurons, the level of high-affinity gamma-aminobutyric acid (GABA) uptake, and choline acetyltransferase enzyme activity. The GABAergic neuronal response to FGF-13 treatment is rapid with a significant increase occurring within 72 h. We have identified a novel member of the FGF family that is expressed in the central nervous system (CNS) and increases the number as well as the level of phenotypic differentiation of cortical neurons in vitro.     

Back to the future in the education and training of psychologists.

In this article, I discuss issues concerning the training and education of psychologists at both the undergraduate and graduate levels. I propose a new introductory course on the applications of psychology to oneself and to society. This course would cover many applications of psychology and would also explain what the major psychological specialties do and the specific training needed to pursue a career in a chosen specialty. A common core of graduate courses is recommended for all graduate students regardless of specialty. A broad-based interdisciplinary course is recommended to ensure that all psychologists know the basic scientific principles that are ultimately essential to the understanding of psychology itself. (PsycINFO Database Record (c) 2010 APA, all rights reserved)