Efficient Metal-Free Catalytic Reduction of Nitro to Amine Over Carbon Sheets Doped with Nitrogen

Catalysis Letters - A highly efficient nitrogen-doped carbon sheet-like material (NCS) is developed via simple pyrolysis of β-cyclodextrin and urea at different temperatures. The effect of the...     

Landscapes of Naïve Bayes classifiers

The performance of the Naïve Bayes classifier (NB) is of interest to many researchers. The desire to improve upon the apparent good performance of NB while maintaining its efficiency and simplicity is demonstrated by the variety of adaptations to NB in the literature. This study takes a look at 37 such adaptations. The idea is to give a qualitative overview of the adaptations rather than a quantitative analysis of their performance. Landscapes are produced using Sammon mapping, Principal Component Analysis (PCA) and Self-Organising feature Maps (SOM). Based on these, the methods are split into five main groups—tree structures, feature selection, space transformation, Bayesian networks and joint features. The landscapes can also be used for placing any new variant of NB to obtain its nearest neighbours as an aid for comparison studies.     

A sensitive and quantitative element-tagged immunoassay with ICPMS detection

We report a set of novel immunoassays in which proteins of interest can be detected using specific element-tagged antibodies. These immunoassays are directly coupled with an inductively coupled plasma mass spectrometer (ICPMS) to quantify the elemental (in this work, metal) component of the reacted tagged antibodies. It is demonstrated that these methods can detect levels of target proteins as low as 0.1-0.5 ng/mL and yield a linear response to protein concentration over 3 orders of magnitude.     

Optimization of the Monte Carlo code for modeling of photon migration in tissue

The Monte Carlo method is frequently used to simulate light transport in turbid media because of its simplicity and flexibility, allowing to analyze complicated geometrical structures. Monte Carlo simulations are, however, time consuming because of the necessity to track the paths of individual photons. The time consuming computation is mainly associated with the calculation of the logarithmic and trigonometric functions as well as the generation of pseudo-random numbers. In this paper, the Monte Carlo algorithm was developed and optimized, by approximation of the logarithmic and trigonometric functions. The approximations were based on polynomial and rational functions, and the errors of these approximations are less than 1% of the values of the original functions. The proposed algorithm was verified by simulations of the time-resolved reflectance at several source-detector separations. The results of the calculation using the approximated algorithm were compared with those of the Monte Carlo simulations obtained with an exact computation of the logarithm and trigonometric functions as well as with the solution of the diffusion equation. The errors of the moments of the simulated distributions of times of flight of photons (total number of photons, mean time of flight and variance) are less than 2% for a range of optical properties, typical of living tissues. The proposed approximated algorithm allows to speed up the Monte Carlo simulations by a factor of 4. The developed code can be used on parallel machines, allowing for further acceleration.     

Understanding the Potential In Vitro Modes of Action of Bis(β-diketonato) Oxovanadium(IV) Complexes

To understand the potential in vitro modes of action of bis(β-diketonato) oxovanadium(IV) complexes, nine compounds of varying functionality have been screened using a range of biological techniques. The antiproliferative activity against a range of cancerous and normal cell lines has been determined, and show these complexes are particularly sensitive against the lung carcinoma cell line, A549. Annexin V (apoptosis) and Caspase-3/7 assays were studied to confirm these complexes induce programmed cell death. While gel electrophoresis was used to determine DNA cleavage activity and production of reactive oxygen species (ROS), the Comet assay was used to determine induced genomic DNA damage. Additionally, Förster resonance energy transfer (FRET)-based DNA melting and fluorescent intercalation displacement assays have been used to determine the interaction of the complexes with double strand (DS) DNA and to establish preferential DNA base-pair binding (AT versus GC).     

Computation in networks of passively mobile finite-state sensors

The computational power of networks of small resource-limited mobile agents is explored. Two new models of computation based on pairwise interactions of finite-state agents in populations of finite but unbounded size are defined. With a fairness condition on interactions, the concept of stable computation of a function or predicate is defined. Protocols are given that stably compute any predicate in the class definable by formulas of Presburger arithmetic, which includes Boolean combinations of threshold-k, majority, and equivalence modulo m. All stably computable predicates are shown to be in NL. Assuming uniform random sampling of interacting pairs yields the model of conjugating automata. Any counter machine with O(1) counters of capacity O(n) can be simulated with high probability by a conjugating automaton in a population of size n. All predicates computable with high probability in this model are shown to be in P; they can also be computed by a randomized logspace machine in exponential time. Several open problems and promising future directions are discussed. Supported in part by NSF grants CCR-9820888, CCR-0098078, and CNS-0305258 (Aspnes), by ONR grant N00014-01-1-0795 (Diamadi), and by NSF grant CSE-0081823 (Fischer and Peralta). A preliminary version of this paper appeared in the proceedings of the 23rd ACM SIGACT-SIGOPS Symposium on Principles of Distributed Computing, St. John’s, Newfoundland, Canada, July 2004.     

Multi‐criteria Evaluation of Mobile Network Sharing Policies in Korea

Mobile operators in saturated markets increasingly favor mobile network sharing (MNS) over facility‐based competition. Previous research examining MNS primarily focused on its positive effects, while the negative effects were largely overlooked. This study proposes a decision‐making model using an analytic hierarchy process technique to evaluate decision‐making criteria among various types of MNS policies. The decision‐making model was applied to Wireless Broadband services in Korea to determine the relative importance of both positive and negative evaluation criteria and preference among multiple types of MNS policies. Positive evaluation criteria (that is, efficiency) were far greater in importance than negative evaluation criteria (that is, competition harm). The preference for adopting MNS among five alternative approaches was also revealed. The study findings offer immediate policy insights in Korea and provide a decision‐making framework for policy makers in other countries to utilize.     

Pictorial depth increases body sway.

This study examines the effects of pictorial depth on postural stability. In our first experiment, two abstract paintings by Maria Elena Vieira Da Silva (1908–1992) were used. Viewing the unaltered paintings induced greater body sway in participants than the cubist transformations of the same paintings in which depth cues were neutralized. In our second experiment, a Renaissance painting by Piero Della Francesca (c.1415–1492) was used due to its powerful representation of perspective and of sense of a recessed space in the visual field. Participants fixated either the recessed or the foregrounded area of the painting. Body sway was higher in the former case. Thus, body sway can even be modulated within the same painting according to variations of local depth information. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Children's working-memory processes: A response-timing analysis.

Recall response durations were used to clarify processing in working-memory tasks. Experiment 1 examined children's performance in reading span, a task in which sentences were processed and the final word of each sentence was retained for subsequent recall. Experiment 2 examined the development of listening-, counting-, and digit-span task performance. Responses were much longer in the reading- and listening-span tasks than in the other span tasks, suggesting that participants in sentence-based span tasks take time to retrieve the semantic or linguistic structure as cues to recall of the sentence-final words. Response durations in working-memory tasks helped to predict academic skills and achievement, largely separate from the contributions of the memory spans themselves. Response durations thus are important in the interpretation of span task performance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

More than a mirror: The ethics of therapist self-disclosure.

Perspectives on the ethical implications of self-disclosure differ widely. Many authors warn that self-disclosure by a therapist can be exploitative. Some authors also highlight beneficent reasons for disclosing in therapy. The ethicality of a particular self-disclosure is likely to depend on the content of the disclosure, the therapist's rationale for the disclosure, the personality traits of the client to whom the disclosure is made, and the specific circumstances surrounding the disclosure. Research suggests that clients experience both positive and negative consequences as a result of their therapists' self-disclosures. Because of the ambiguity and complexity of this ethical issue, therapists must take into account numerous ethical principles when using interventions that involve self-disclosure. (PsycINFO Database Record (c) 2010 APA, all rights reserved)