Why do lower educated people continue smoking? Explanations from the longitudinal GLOBE study.

This article describes the effect of educational level on the decision to continue smoking among 1,354 initially smoking participants (age≥20 years) in the Dutch GLOBE study. The effect of education continued smoking was explained from baseline information (1991) on smoking characteristics, individual characteristics, and environmental factors. Smoking status was reassessed after 6.5 years. Lower educated smokers more often continued smoking (odds ratio 2.09). Poor perceived health and earlier smoking initiation in lower educated groups were main predictors of educational differences in smoking maintenance. Educational differences in chronic illness, perceived control, neuroticism, and emotional support also contributed to the explanation of educational differences in continued smoking. These results have important implications for intervention programs and policy. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Influence of internal stress and extensibility on the exterior durability of wood coatings

Different types of coatings were characterised for: swelling by moisture, moisture permeability, elastic modulus and extensibility. These data were used to calculate maximum internal stress. Internal stress was also measured directly whilst changing temperature and humidity. The stress data were compared to cracking and flaking results in both natural and accelerated weathering tests. Results showed that high levels of stress occur if there is a difference in swelling between coating and wood. In most cases stress relaxation took place rapidly. Comparing maximum stress, extensibility and cracking, a good correlation between these data was found. The ratio between maximum stress and extensibility appeared to be a very good predictor for crack formation.     

Interpreting spatial and temporal neural activity through a recurrent neural network brain-machine interface.

We propose the use of optimized brain-machine interface (BMI) models for interpreting the spatial and temporal neural activity generated in motor tasks. In this study, a nonlinear dynamical neural network is trained to predict the hand position of primates from neural recordings in a reaching task paradigm. We first develop a method to reveal the role attributed by the model to the sampled motor, premotor, and parietal cortices in generating hand movements. Next, using the trained model weights, we derive a temporal sensitivity measure to asses how the model utilized the sampled cortices and neurons in real-time during BMI testing.     

Interfacial chemistry of cobalt(II) during sol–gel synthesis of cobalt-containing mesoporous materials

Co-MCM-41 and Co-MCM-48 with cobalt amounts from about 3 wt.% to 9 wt.% have been synthesized under various conditions, and the samples were characterized by XRF, XRD and N₂-sorption. EXAFS least-squares curve fitting detected only oxygen and silicon backscattering shells, which verified the incorporation of cobalt into the silica framework both for as-synthesized and calcined samples. XANES profiles showed that the oxidation state of cobalt in the samples is unaltered during synthesis. It has been shown that the cobalt is precipitated as cobalt hydroxide during synthesis, and this hydroxide is in equilibrium with aqueous cobalt ions in the synthesis gel. The precipitated cobalt hydroxide precursors are incorporated into the mesoporous silica framework, while the aqueous cobalt ions remain dissolved in the aqueous phase. The cobalt amount in the final samples is therefore pH dependent. This equilibrium is also important in the formation of the mesoporous structure. Addition of increasing amounts of cobalt salt to a MCM-48 synthesis gel causes a change in the mesoporous structure from cubic Ia3d to hexagonal, which is suggested to be a consequence of the charge density matching process. The increased amounts of the divalent cobalt(II) ions in the gel screen the negatively charged silica precursors, which decreases the total surface charge density of the silica, and thus causes the surfactants to self-assemble into the hexagonal structure.     

Monopolistic competition, increasing returns, agglomeration, and transport costs

This paper presents a model where production concentrated in one place is compared with dispersed production. Concentrated production can attain a higher level of productivity but must incur transport costs. Dispersed production, on the other hand, has a lower productivity level but need no transportation. In order to avoid unnecessary complications, output per capita is used as an objective function. Transport cost is measured in units of output and will therefore affect the objective function directly. The model uses a linkage approach where a final output is produced under constant returns to scale. This production has increasing returns to the number of differentiated inputs. The differentiated intermediate inputs are produced subject to increasing returns to scale in a framework of Chamberlinian monopolistic competition. The size of the market determines the number of intermediate inputs that the local economy can accommodate. In this way the model formalises Adam Smith's theorem on the division of labour being limited by the extent of the market. The paper examines how the break-even point between the two ways of organising production is affected by (i) changes in transport cost and market density and (ii) shifts in technology for producers of intermediaries and the final output. Received: December 1999/Accepted: January 2001     

Identification of a periodic time series from an environmental proxy record

The past environment is often reconstructed by measuring a certain proxy (e.g. δ¹⁸O) in an environmental archive, i.e. a species that gradually accumulates mass and records the current environment during this mass formation (e.g. corals, shells, trees, etc.). When such an environmental proxy is measured, its values are known on a distance grid. However, to relate the data to environmental variations, the date associated with each measurement has to be known too. This transformation from distance to time is not straightforward to solve, since species usually do not grow at constant or known rates. In this paper, we investigate this problem for environmental archives exhibiting a certain periodicity. In practice, the method will be applicable to most annually resolved archives because these contain a seasonal component, e.g. clams, corals, sediment cores or trees. Due to variations in accretion rate the data along the distance axis have a disturbed periodic profile. In this paper, a method is developed to extract information about the accretion rate, such that the original (periodic, but further unknown) signal as a function of time can be recovered. The final methodology is quasi-independent of choices made by the investigator and is designed to deliver the most precise and accurate result. Every step in the procedure is described in detail, the results are tested on a Monte-Carlo simulation, and finally the method is exemplified on a real world example.     

Electropolymerization of N-methylanthranilic acid and spectroelectrochemical characterization of the formed film

The electropolymerization of N-methylanthranilic acid (NMAA) is reported in this paper. The monomer is substituted both at ortho- and N-position and, to the best of our knowledge, it has not been previously electropolymerized. Electropolymerization of NMAA was done on glassy carbon and optically transparent (indium) tin oxide electrodes. The obtained films, which are probably of an oligomeric nature (oligoNMMA), were characterized with cyclic voltammetry (CV), in situ UV–vis and Raman spectroscopy, ex situ FTIR spectroscopy and scanning electron microscopy (SEM).Our results show that NMAA can be electropolymerized as thin films in 1.0 M HClO₄, but the oxidation and reduction peak currents in the CVs indicate that the formed oligoNMAA films are thinner than poly(N-methylaniline) or poly(N-butylaniline) films prepared under similar conditions. The CV and UV–vis measurements confirm that oligoNMAA have three oxidation states like suggested in the redox scheme of substituted polyanilines. The Raman spectra of oligoNMAA also verify that more quinoid units are formed at higher potentials in accordance with the redox scheme. The ex situ FTIR measurement proves that covalently attached carboxylic acid groups are present in the film structure and attached to the oligoNMAA backbone.     

Monitoring struturants of fat blends with ultrasound based in‐line rheometry (ultrasonic velocity profiling with pressure difference)

Ultrasonic velocity profiling with pressure difference (UVP‐PD) was demonstrated to be a successful, non‐invasive, in‐line measurement system for instantaneous velocity and rheological flow profiling of complex, opaque fat blends. Model systems of 25% Akomic, 75% rapeseed oil; and 25% Akomic, 74% rapeseed oil and 1% Grindsted^® Crystalliser 110 were compared under real process conditions with UVP‐PD. Results indicated that the sample containing the crystalliser had twice the viscosity of the control. These in‐line results are in agreement with previous off‐line results, and offer the chance to probe the mechanics of fat blend physics under real, dynamic conditions.     

Practical Construction and Analysis of Pseudo-Randomness Primitives

We give a careful, fixed-size parameter analysis of a standard (Blum and Micali in SIAM J. Comput. 13(4):850–864, 1984; Goldreich and Levin in Proceedings of 21st ACM Symposium on Theory of Computing, pp. 25–32, 1989) way to form a pseudo-random generator from a one-way function and then pseudo-random functions from said generator (Goldreich et al. in J. Assoc. Comput. Mach. 33(4):792–807, 1986) While the analysis is done in the model of exact security, we improve known bounds also asymptotically when many bits are output each round and we find all auxiliary parameters efficiently, giving a uniform result. These optimizations makes the analysis effective even for security parameters/key-sizes supported by typical block ciphers and hash functions. This enables us to construct very practical pseudo-random generators with strong properties based on plausible assumptions.