Mechanism of fragmentation and atomization of molecular ions in gasdynamic transport cell

The fragmentation of molecular ions formed upon the electrospraying of a sample and transported through the gasdynamic system of a mass spectrometer equipped with an IESAP (Ion Extraction from Solution at Atmospheric Pressure) source has been experimentally studied. It is established that ion fragmentation in a Kantorowicz-Gray type cell takes place in the immediate vicinity of a skimmer port, apparently, as a result of collisions between ions (accelerated in an electric field) and stagnant gas. Molecular mechanisms of fragmentation are considered and it is concluded that this process can take place in a single ion-molecule collision even

Crossover from Endogenous to Exogenous Activity in Open-Source Software Development

We have investigated the origin of fluctuations in the aggregated behaviour of an open-source software community. In a recent series of papers, de Menezes and co-workers have shown how to separate internal dynamics from external fluctuations by capturing the simultaneous activity of many system's components. In spite of software development being a planned activity, the analysis of fluctuations reveals how external driving forces can be only observed at weekly and higher time scales. Hourly and higher change frequencies mostly relate to internal maintenance activities. There is a crossover from endogenous to exogenous activity depending on the average number of file changes. This new evidence suggests that software development is a non-homogeneous design activity where stronger efforts focus in a few project files. The crossover can be explained with a Langevin equation associated to the cascading process, where changes to any file trigger additional changes to its neighbours in the software network. In addition, analysis of fluctuations enables us to detect whether a software system can be decomposed in several subsystems with different development dynamics.Comment: 7 pages, 4 figures, submitted to Europhysics Letter

Impact of cultural behaviour on indoor comfort: Examining the air quality in Homes and exploring observational and experimental methods of representation through filmmaking

There is a limited understanding of householders’ cultural differences and their impact on spatial organisation and energy behaviour in dwellings. Indoor air quality directly impacts the health and well-being of occupants. The airborne COVID-19 epidemic has highlighted shortcomings of controlled ventilation systems in recent reports (PHE, Dec 2020). While efficiency interventions can make homes more affordable to heat, they can exacerbate conditions such as asthma, due to reduced indoor air quality and ventilation. Preliminary research conducted in Plymouth by the applicant indicates that British Asians use their homes differently compared to native British in terms of spatial organisation, cooking habits (on average, they spend five times more time cooking the daily meal) and ventilation strategies, all of which have an impact on indoor air quality. This project sets out to establish the impact of culturally informed choices on indoor air quality and the extent to which the norms that guide the design of energy-efficient homes ignore potentially significant cultural and behavioural differences. It will achieve this by focusing on the impact of energy behaviour and choices related to cooking on the indoor air quality of British-Asian households. The project aims to quantify temperature, humidity and air quality by data collected by a pilot study in Plymouth, UK. We will engage the community in a participatory methodology using correlational research and survey questionnaires and IAQ Data Loggers to evidence anomalies from the design norms currently used in the UK. In addition to traditional data analysis, our methodology includes artistic research, utilising observational and sensory ethnographic filmmaking techniques, to support, document, and evidence the impact of cooking in the home. We aim to explore how the intersection between these two methods can reveal and communicate new perspectives. The main outcome is to evaluate the impact of cultural behaviour on the air quality of super-insulated British-Asian homes through an interdisciplinary methodology. This project lays foundations for larger-scale research working with diverse ethnic minority communities to promote engagement in a low-carbon society.</jats:p

Character of jet flows in mass-spectrometric interfaces at various pressures and chamber lengths

Samples-in particular, of bioorganic matter—are usually introduced into a mass spectrometer from atmosphere to high vacuum via a gasdynamic interface that represents a chamber with intermediate pressure or a system of chambers with gradually decreasing pressure. Transformation of the character of an expanding jet flow in a single-chamber interface has been studied as dependent on the chamber length and pressure. Knowledge of this character allows the system parameters to be most effectively used so as to ensure high ion transmission and decrease mass discriminatio

Takeaway food consumption, diet quality and abdominal obesity in young adults

Background - Takeaway food consumption is associated with a higher BMI and poorer diet quality in the USA but little is known about the association in Australians.Objective - To examine if takeaway food consumption is associated with abdominal obesity and poorer diet quality in young Australian adults.Design - A national sample of 1,277 men and 1,585 women aged 26-36 completed a self-administered questionnaire on demographic and lifestyle factors, a 127 item food frequency questionnaire, and usual frequency of fruit, vegetable and takeaway food consumption. Dietary intake was compared with the dietary recommendations of the Australian Guide to Healthy Eating. A pedometer was worn for seven days. Waist circumference was measured and moderate abdominal obesity was defined as &ge;94 cm for men and &ge;80 cm for women. Prevalence ratios (PR) were calculated using log binomial regression with eating takeaway food once a week or less as the reference group.Outcomes - Consumption of takeaway food twice a week or more was reported by more men (37.9%) than women (17.7%). Participants eating takeaway food at least twice a week were less likely to meet the guidelines for vegetables (P&lt;0.05 men and women), fruit (P&lt;0.001 men and women), dairy (P&lt;0.01 men and women), extra foods (P=0.001 men and women), breads and cereals (P&lt;0.05 men only), lean meats and alternatives (P&lt;0.05 women only) and overall met significantly fewer dietary guidelines (P&lt;0.001 men and women) than participants eating takeaway less than twice per week. After adjusting for confounding variables (age, physical activity, TV viewing, and employment status) consuming takeaway food twice a week or more was associated with a 31% higher prevalence of moderate abdominal obesity in men (PR 1.31; 95% CI: 1.07, 1.61) and a 25% higher prevalence in women (PR 1.25; 95% CI: 1.04, 1.50).Conclusion - Eating takeaway food twice a week or more was associated with poorer diet quality and a higher prevalence of moderate abdominal obesity in both young men and young women.<br /

Development and preliminary validation of a tool measuring concordance and belief about performing pressure-relieving activities for pressure ulcer prevention in spinal cord injury

Objective: To develop and examine the reliability, and validity of a questionnaire measuring concordance for performing pressure-relief for pressure ulcer (PrU) prevention in people with Spinal Cord Injury (SCI). Methods: Phase I included item development, content and face validity testing. In phase II, the questionnaire was evaluated for preliminary acceptability, reliability and validity among 48 wheelchair users with SCI. Results: Thirty-seven items were initially explored. Item and factor analysis resulted in a final 26-item questionnaire with four factors reflecting concordance, perceived benefits, perceived negative consequences, and personal practical barriers to performing pressure-relief activities. The internal consistency reliability for four domains were very good (Cronbach's α = .75-.89). Pearson correlation coefficient on a test-retest of the same subjects yielded significant correlations in concordance (r = .91, p = .005), perceived benefit (r = .71, p < .04), perceived negative consequences (r = .98, p < .0001), personal barriers (r = .93, p= .002). Participants with higher levels of concordance reported a greater amount of pressure-relieving performed. Individuals viewing PrU as a threatening illness were associated with higher scores of concordance and tended to report a greater amount of pressure-relieving performance which provides evidence of criterion related validity. Conclusion: The new questionnaire demonstrated good preliminary reliability and validity in people with SCI. Further evaluation is necessary to confirm these findings using larger samples with follow-up data for predictive validity. Such a questionnaire could be used by clinicians to identify high risk of patients and to design individualised education programme for PrU prevention

{PoseTrackReID}: {D}ataset Description

Current datasets for video-based person re-identification (re-ID) do not include structural knowledge in form of human pose annotations for the persons of interest. Nonetheless, pose information is very helpful to disentangle useful feature information from background or occlusion noise. Especially real-world scenarios, such as surveillance, contain a lot of occlusions in human crowds or by obstacles. On the other hand, video-based person re-ID can benefit other tasks such as multi-person pose tracking in terms of robust feature matching. For that reason, we present PoseTrackReID, a large-scale dataset for multi-person pose tracking and video-based person re-ID. With PoseTrackReID, we want to bridge the gap between person re-ID and multi-person pose tracking. Additionally, this dataset provides a good benchmark for current state-of-the-art methods on multi-frame person re-ID

Does ethnicity affect how older adults deal with stressors at home?

Numerous studies have examined stress in older adults but little research has examined the specific relationship between ethnicity and home stressors. We used a micro-longitudinal eight day daily diary study to examine reactivity to home stressors in older adults. 42 participants reported on 337 days from the Greater Raleigh Area all between the ages of 60 to 96 representing European-Americans and African-Americans. Participants reported their daily home stressor resolution (resolved or unresolved) and daily physical symptoms (e.g., joint pain, fatigue, headache). We found that European-Americans had a significantly higher number of physical symptoms on days with an unresolved home stressor than that of their African-American counterparts. Findings suggest ethnicity differences in the physical effects of home stressor resolution among older adults. Awareness of disparity is an important first step in closing the health gap and ethnicity should be included in future assessments of home stressors in older adults