Comparison of Particle Number Counts Measured with an Ink Jet Aerosol Generator and an Aerodynamic Particle Sizer

Aerodynamic particle sizer (APS) users typically calibrate the particle sizing capabilities, but not the counting efficiency upon which aerosol concentration results are based. Herein, comparisons were made between the counts provided by an ink jet aerosol generator (IJAG) with those measured by an APS. Near-monodisperse (geometric standard deviation of about 1.06) liquid or solid aerosols in the size range of 0.95 to 13.3 μm aerodynamic diameter (AD) generated with an IJAG were released into the inner inlet-tube of the APS in a manner that rendered APS wall and aspiration losses negligible. For most experiments, the IJAG generated 75 particles/s, which rate was maintained by the IJAG system through control of electrical pulses applied to its ink jet cartridge. For particles in the size range of 2–13.3 μm AD, the ratio of relative detection efficiency (ratio of the number of particles counted by the APS to the number reported as generated by the IJAG) was 99.3 ± 1.4%; however, for test particles between 0.95 and 2 μm AD, the relative detection efficiency was somewhat lower, but the drop off was less than about 2%. This slight drop off is likely associated with the light scattering detection approach and corresponding counting algorithm of the APS. Tests were conducted where the IJAG produced 7.0 μm AD particles at rates of 1 to 500 s^-1 and the results showed essentially a 1:1 correspondence between IJAG and APS counts. The presence of smaller-sized background particles did not affect the measured APS counts of larger-sized challenge particles.

Copyright 2014 American Association for Aerosol Research     

Secure base processes in couples: Daily associations between support experiences and attachment security.

The authors examined secure base functioning in couples by studying the association between daily social support experiences and attachment security in a 14-day daily experiences study of 114 heterosexual dating couples. Both members of each couple reported on daily relationship-specific attachment security and support sought, provided, and received, as well as felt support. Within- and cross-partner associations were examined, as were reciprocal associations between support and security. Results of over-time Actor-Partner Interdependence Model analyses indicated that security (in the form of high comfort with intimacy and low anxiety about abandonment) was associated with the most adaptive support experiences, whereas high anxiety about abandonment was associated with the least, and particularly with a lack of sensitive caregiving. Implications for understanding secure base dynamics in couples are discussed and guidelines for where to intervene as well as what to target in relationship distress prevention programs are provided. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Emotion dysregulation in the intergenerational transmission of romantic relationship conflict.

The role of emotion dysregulation in the intergenerational transmission of romantic relationship conflict was examined using multimethod and multiagent prospective longitudinal data across 21 years for 190 men and their mothers and fathers. As predicted, an individual’s emotion dysregulation was a key mediator in the transmission of relationship conflict, along with poor parenting skills. Parents’ emotion dysregulation was directly related to their son’s emotion dysregulation, which was in turn associated with the son’s later relationship conflict. Additionally, parents’ emotion dysregulation was significantly related to their poor discipline skills, which were linked to the son’s emotion dysregulation and eventual relationship conflict. Findings highlight emotion dysregulation as a significant mechanism explaining the continuity of romantic relationship conflict across generations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Scanning electron microscope (SEM) disclosure of the effects of snake venom on living tissue integrity and cell surfaces

The tissue destruction produced by the bite of the viper is well known and the venom enzyme[s] that produce it have been thoroughly studied. Not so well examined is the view of the damage available to the electron microscope, especially the scanning electron microscope. Here we have used the SEM to view the effects of viper venom on living tissue in situ. SCANNING 32: 155–158, 2010. © 2010 Wiley Periodicals, Inc.     

Attention as inference: Selection is probabilistic; responses are all-or-none samples.

Theories of probabilistic cognition postulate that internal representations are made up of multiple simultaneously held hypotheses, each with its own probability of being correct (henceforth, “probability distributions”). However, subjects make discrete responses and report the phenomenal contents of their mind to be all-or-none states rather than graded probabilities. How can these 2 positions be reconciled? Selective attention tasks, such as those used to study crowding, the attentional blink, rapid serial visual presentation, and so forth, were recast as probabilistic inference problems and used to assess how graded, probabilistic representations may produce discrete subjective states. The authors asked subjects to make multiple guesses per trial and used 2nd-order statistics to show that (a) visual selective attention operates in a graded fashion in time and space, selecting multiple targets to varying degrees on any given trial; and (b) responses are generated by a process of sampling from the probabilistic states that result from graded selection. The authors concluded that although people represent probability distributions, their discrete responses and conscious states are products of a process that samples from these probabilistic representations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Searching for differences in race: Is there evidence for preferential detection of other-race faces?

Previous research has suggested that like animal and social fear-relevant stimuli, other-race faces (African American) are detected preferentially in visual search. Three experiments using Chinese or Indonesian faces as other-race faces yielded the opposite pattern of results: faster detection of same-race faces among other-race faces. This apparently inconsistent pattern of results was resolved by showing that Asian and African American faces are detected preferentially in tasks that have small stimulus sets and employ fixed target searches. Asian and African American other-race faces are found slower among Caucasian face backgrounds if larger stimulus sets are used in tasks with a variable mapping of stimulus to background or target. Thus, preferential detection of other-race faces was not found under task conditions in which preferential detection of animal and social fear-relevant stimuli is evident. Although consistent with the view that same-race faces are processed in more detail than other-race faces, the current findings suggest that other-race faces do not draw attention preferentially. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The impact of family and community violence on children’s depression trajectories: Examining the interactions of violence exposure, family social support, and gender.

This longitudinal study used multilevel modeling to examine the relationships between witnessing intimate partner violence (IPV), community and school violence exposure (CSVE), family social support, gender, and depression over 2 years within a sample of 100 school-aged children. We found significant between-child differences in both the initial levels of depression and the trajectories of depression; depression over time was positively associated with change in witnessing IPV and CSVE and negatively associated with change in support. Two significant 3-way interactions were found: Gender and initial support, as well as gender and initial witnessing IPV, both significantly moderated the effect of change in witnessing IPV on the children’s depression over time. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Family Mealtime Q-Sort: A measure of mealtime practices.

Studies outlining the protective functions of shared family meals suggest that helping families experience successful meals is an important goal. Measuring the effectiveness of family mealtime interventions necessitates the ability to quantify both the frequency and context of shared mealtimes. This article introduces a new instrument, the Family Mealtime Q-Sort, describes its development, and presents preliminary data about its psychometric properties. Data from initial evaluation of the Family Mealtime Q-Sort using family mealtime videos (N = 51) demonstrate acceptable interrater reliability, promising validity, and the ability to compare family mealtimes to an independently derived, culturally appropriate standard. The results suggest that the Q-sort adequately measures important dimensions of a successful mealtime including a positive atmosphere, making use of the shared time to engage in meaningful conversation, and proceeding with a clear plan and minimal distractions. Further research on the tool is warranted. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Lightweight Concrete Using Local Industrial By-product

Construction is one of the largest users of energy, material resources and water and it is a formidable polluter. One of the major materials used in construction is concrete and ordinary concrete contains about 12% cement which is a major producer of greenhouse gas in the world. The use of waste materials as partial replacement of cement in concrete reduces greenhouse gases, frees up land fill space, and reduces raw materials consumption. This contributes towards sustainable development, as in a sustainable society, nature is not subject to systematically increasing concentrations of substances extracted from the earth＇s crust. This research work explores the possibility of replacing some percentage of cement in concrete with marble sludge powder to produce lightweight concrete. This was achieved by determining the compressive strength and some hardened properties of concrete like sorptivity and carbonation with marble sludge. The results so far have been able to prove that lightweight concrete can be produced when some percentage of cement is replaced with this waste.