Measuring Particulate Mass Emissions with the Electrical Low Pressure Impactor

The electrical low pressure impactor (ELPI) is a useful tool for recording transient particle size distributions, such as in motor vehicle emissions. But for sub-micron aerosols, the straightforward mass weighting and integration of these size distributions overestimates the particulate matter (PM) mass by a factor of two or more. The present article examines the sources of this discrepancy and develops an analysis that allows quantitative PM mass measurement with an accuracy of about 20%. This procedure is applied to measure motor vehicle PM emissions, and the results are compared with filter-based gravimetric determinations. Good agreement is achieved for diesel and direct injection gasoline vehicles. For particulate trap equipped diesel vehicles and conventional gasoline vehicles, the PM mass recorded by the ELPI is often substantially lower than the filter based mass owing to the gaseous adsorption artifact of the latter. Accurate work at very low emissions levels, less than ～ 1 mg/mi, requires further study of how reliably the ELPI can provide semivolatile nanoparticle mass as well as an improved understanding of filter-based vehicle exhaust measurement.     

Mid‐infrared spectroscopy and multivariate curve resolution for analyzing human adipose tissue triacylglycerols

The aim of this study was to evaluate use of infrared spectroscopy for measuring adipose tissue triacylglycerols (TAGs) with analysis by multivariate curve resolution (MCR). The mid‐infrared spectrum was measured with an attenuated total reflection accessory from a lipid droplet pressed from adipose tissue. The obtained spectra were characteristic of pure TAG spectra and water and protein contamination could be easily identified from specific spectral regions. MCR analysis of the olefinic (?C? H) stretch (3006 cm^?1), resolved the different contributions of monounsaturated (MUFA) and polyunsaturated (PUFA) double bonds. Similar MCR analysis of the trans (HC?CH? ) region (966 cm^?1), resolved the differing contributions of isolated trans isomers (transFA) and CLA. The PUFA double bond content of 16 subjects was negatively correlated with concentrations of serum total cholesterol R = ?0.498 (p = 0.050) and triacylglycerols R = ?0.609, (p = 0.016). The transFA content exhibited a negative, although non‐significant, correlation to high‐density lipoprotein (HDL)‐cholesterol (R = ?0.483, p = 0.068). The present study shows that MCR analysis of adipose tissue TAG infrared spectra can be used to estimate differences in the fatty acid (FA) profiles in population studies. Infrared spectroscopy in combination with MCR provides a robust method for assessing a FA profile of human adipose tissue. Practical applications: This study has highlighted the use of MCR to enhance the information obtained from infrared spectra. This new approach provides a robust method for assessing a FA profile of human adipose tissue lipids.     

The comparison of particle oxidation and surface structure of diesel soot particles between fossil fuel and novel renewable diesel fuel

Conventional fossil diesel fuel and renewable diesel fuel based on hydrotreated vegetable oils (HVO) were compared regarding the oxidation characteristics of the generated soot particulate. The comparison was performed by utilizing a high-temperature oxidation tandem differential mobility analyser in which monodisperse soot aerosol was first selected and then heated in a high-temperature furnace. The particle size reduction caused by oxidation during the furnace treatment was then measured as a function of furnace temperature. The results indicate that soot oxidation is very similar between the studied fuels. This is supported by the obtained HR-TEM images and EELS-spectra which were practically indistinguishable between different fuels and engine conditions. The similar oxidation properties and surface structure between fossil and HVO-based diesel fuels imply that the oxidative aftertreatment devices designed for fossil diesel should work well also with the studied renewable diesel fuel.     

Incorporation of n-3 fatty acids into plasma lipid fractions, and erythrocyte membranes and platelets during dietary supplementation with fish, fish oil, and docosahexaenoic acid-rich oil among healthy young men

The effects of n-3 fatty acid supplementation in the form of fresh fish, fish oil, and docosahexaenoic acid (DHA) oil on the fatty acid composition of plasma lipid fractions, and platelets and erythrocyte membranes of young healthy male students were examined. Altogether 59 subjects (aged 19–32 yr, body mass index 16.8–31.3 kg/m²) were randomized into the following diet groups: (i) control group; (ii) fish diet group eating fish meals five times per week [0.38±0.04 g eicosapentaenoic acid (EPA) and 0.67±0.09 g DHA per day]; (iii) DHA oil group taking algae-derived DHA oil capsules (1.68 g/d DHA oil group taking algae-derived DHA oil capsules (1.68 g/d DHA in triglyceride form); and (iv) fish oil group (1.33 g EPA and 0.95 g DHA/d as free fatty acids) for 14 wk. The fatty acid composition of plasma lipids, platelets, and erythrocyte membranes was analyzed by gas chromatography. The subjects kept 4-d food records four times during the study to estimate the intake of nutrients. In the fish diet, in DHA oil, and in fish oil groups, the amounts of n-3 fatty acids increased and those of n-6 fatty acids decreased significantly in plasma lipid fractions and in platelets and erythrocyte membranes. A positive relationship was shown between the total n-3 polyunsaturated fatty acids (PUFA) and EPA and DHA intake and the increase in total n-3 PUFA and EPA and DHA in all lipid fractions analyzed. DHA was preferentially incorporated into phospholipid (PL) and triglyceride (TG) and there was very little uptake in cholesterol ester (CE), while EPA was preferentially incorporated into PL and CE. The proportion of EPA in plasma lipids and platelets and erythrocyte membranes increased also by DHA supplementation, and the proportion of linoleic acid increased in platelets and erythrocyte membranes in the DHA oil group as well. These results suggest retroconversion of DHA to EPA and that DHA also interferes with linoleic acid metabolism.     

Conformational Solvation Studies of LIGNOLs with Molecular Dynamics and Conductor-Like Screening Model

Molecular dynamics (MD) simulations were performed on sterically hindered α-conidendrin-based chiral 1,4-diols (LIGNOLs) from the naturally occurring lignan hydroxymatairesinol (HMR) using the GROMACS software. The aim of this study was to explore the conformational behaviour of the LIGNOLs in aqueous solution adopting the TIP4P model. The topologies of the LIGNOLs were constructed manually and they were modeled with the OPLS-AA force field implemented in GROMACS. The four most relevant torsional angles in the LIGNOLs were properly analyzed during the simulations. The determining property for the conformation preferred in aqueous solution was found to be the lowest energy in gas phase. The solvation effects on the LIGNOLs were also studied by quantum chemical calculations applying the COnductor-like Screening MOdel (COSMO). The hydration studies of the MD simulations showed that several of these LIGNOLs, produced from a renewable source, have a great potential of acting as chiral catalysts.     

Development of a bioluminescence resonance energy-transfer assay for estrogen-like compound in vivo monitoring

A new bioluminescence resonance energy transfer (BRET) homogeneous assay to evaluate the presence of estrogen-like compounds has been developed and optimized. The assay is based on the direct evaluation of estrogen alphareceptor (ERalpha) homodimerization as a result of estrogen-like compound binding. ERalpha monomer was genetically fused either to Renilla luciferase (Rluc) or to enhanced yellow fluorescent protein (EYFP). In the presence of estrogens, ERalpha dimerization brings Rluc and EYFP molecules close enough for an energy transfer. An in vitro BRET assay was first developed using purified fusion proteins (ERalpha-Rluc and ERalpha-EYFP) expressed in Escherichia coli to evaluate and optimize the analytical performances of the assay in the presence of 17-beta estradiol. The "in vivo" BRET quantitative assay was then developed by coexpressing the two fusion proteins in live HepG2 cells. The assay can be performed in 96-well microplate format with a 30-min incubation and allows detection with adequate accuracy and precision of as low as 1 nM of 17-beta estradiol. This new "in vivo" BRET assay allows evaluating the estrogen-like activity and synthetic xenoestrogens from biological and environmental samples.     

MORE – a multimodal observation and analysis system for social interaction research

The MORE system is designed for observation and machine-aided analysis of social interaction in real life situations, such as classroom teaching scenarios and business meetings. The system utilizes a multichannel approach to collect data whereby multiple streams of data in a number of different modalities are obtained from each situation. Typically the system collects a 360-degree video and audio feed from multiple microphones set up in the space. The system includes an advanced server backend component that is capable of performing video processing, feature extraction and archiving operations on behalf of the user. The feature extraction services form a key part of the system and rely on advanced signal analysis techniques, such as speech processing, motion activity detection and facial expression recognition in order to speed up the analysis of large data sets. The provided web interface weaves the multiple streams of information together, utilizes the extracted features as metadata on the audio and video data and lets the user dive into analyzing the recorded events. The objective of the system is to facilitate easy navigation of multimodal data and enable the analysis of the recorded situations for the purposes of, for example, behavioral studies, teacher training and business development. A further unique feature of the system is its low setup overhead and high portability as the lightest MORE setup only requires a laptop computer and the selected set of sensors on site.     

Episodic remembering in a population-based sample of nonagenarians: Does major depression exacerbate the memory deficits seen in Alzheimer's disease?

Population-based samples of normal old adults and people with major depression (MD), Alzheimer's disease (AD), and coexisting MD and AD (MD + AD) between 90 and 100 years of age were assessed in face recognition, word recall, and object recall. Results indicated a consistent pattern across tasks: no differences between the normal old and the MD participants or between the AD and MD + AD participants in any task, a clear performance decrement in the AD and MD + AD participants in all task variables reflecting long-term episodic memory, and no group differences in those variables reflecting short-term memory. These data suggest that depression in very old age may not exacerbate the episodic memory deficit that accompanies AD. Further, differences between normal old and MD participants in episodic memory tasks appear to be negligible among the oldest old. The general lack of effects of MD may be due to the fact that those symptoms of this disease that are most likely to affect memory functioning (e.g., loss of energy, concentration difficulties) are common in AD as well as in nondepressed people in the 10th decade of life. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

How to deal with unbelievable assertions

We tackle the problem that arises when an agent receives unbelievable information. Information is unbelievable if it conflicts with the agent’s convictions, that is, what the agent considers knowledge. We propose two solutions based on modifying the information so that it is no longer unbelievable. In one solution, the source and the receiver of the information cooperatively resolve the conflict. For this purpose we introduce a dialogue protocol in which the receiver explains what is wrong with the information by using logical interpolation, and the source produces a new assertion accordingly. If such cooperation is not possible, we propose an alternative solution in which the receiver revises the new piece of information by its own convictions to make it acceptable.