Advancement on Thermal Comfort in Educational Buildings: Current Issues and Way Forward

The thermal environment in educational buildings is crucial to improve students’ health and productivity, as they spend a considerable amount of time in classrooms. Due to the complexity of educational buildings, research performed has been heterogeneous and standards for thermal comfort are based on office studies with adults. Moreover, they rely on single dose-response models that do not account for interactions with other environmental factors, or students’ individual preferences and needs. A literature study was performed on thermal comfort in educational buildings comprising of 143 field studies, to identify all possible confounding parameters involved in thermal perception. Educational stage, climate zone, model adopted to investigate comfort, and operation mode were then selected as confounding parameters and discussed to delineate the priorities for future research. Results showed that children often present with different thermal sensations than adults, which should be considered in the design of energy-efficient and comfortable educational environments. Furthermore, the use of different models to analyse comfort can influence field studies’ outcomes and should be carefully investigated. It is concluded that future studies should focus on a more rational evaluation of thermal comfort, also considering the effect that local discomfort can have on the perception of an environment. Moreover, it is important to carefully assess possible relationships between HVAC systems, building envelope, and thermal comfort, including their effect on energy consumption. Since several studies showed that the perception of the environment does not concern thermal comfort only, but it involves the aspects of indoor air, acoustic, and visual quality, their effect on the health and performance of the students should be assessed. This paper provides a way forward for researchers, which should aim to have an integrated approach through considering the positive effects of indoor exposure while considering possible individual differences.

Voice-enabled Intelligent Virtual Agents for People with Amnesia: A Systematic Review (Preprint)

BACKGROUND Older adults often have increasing memory problems, and worldwide about 50 million people have dementia. This syndrome gradually affects a patient over a period of 10-20 years. Intelligent virtual agents may support people suffering from memory problems. OBJECTIVE To identify the state of the art of experimental studies with virtual agents on a screen capable of verbal dialogues with older adults with memory problems. METHODS Conduct a systematic search into selected databases PubMed, SCOPUS, Microsoft Academic, Google Scholar, Web of Science and CrossRef on Virtual Agent and Memory Problems on papers that describe such experiments. Search criteria were (“Virtual Agent” OR “Virtual Assistant” OR “Virtual Human” OR “Conversational Agent” OR “Virtual Coach” OR Chatbot) AND (Dementia OR Alzheimer OR Amnesia OR “Mild Cognitive Impairment”). Risk of bias has been evaluated using the QualSyst tool that scores 14 study quality items. Eligible studies are reported in a table including country, study design type, target sample size, controls, study aims, experiment population, intervention details, results and an image of the agent. RESULTS Nine studies were included. The average number of participants in the studies was 18 (SD=12). The verbal interactions were generally short. The human utterance consisted in 8 out of 9 studies out of short words or phrases that were predefined in the agent’s speech recognition algorithm. The average study quality score was .68 (SD=.08) on a scale 0-1.The number of experimental studies on talking virtual agents that support people with memory problems is still small. The details on the verbal interaction are limited, which make it difficult to assess the quality of that interaction and the possible effect of confounding parameters. Further research is needed with extended and prolonged dialogues. CONCLUSIONS The number of experimental studies on talking virtual agents that support people with memory problems is still small. The details on the verbal interaction are limited, which make it difficult to assess the quality of that interaction and the possible effect of confounding parameters. Further research is needed with extended and prolonged dialogues.

Regression analysis of unmeasured confounding

When studying the causal effect of x on y, researchers may conduct regression and report a confidence interval for the slope coefficient ${\beta }_{x}$. This common confidence interval provides an assessment of uncertainty from sampling error, but it does not assess uncertainty from confounding. An intervention on x may produce a response in y that is unexpected, and our misinterpretation of the slope happens when there are confounding factors w. When w are measured we may conduct multiple regression, but when w are unmeasured it is common practice to include a precautionary statement when reporting the confidence interval, warning against unwarranted causal interpretation. If the goal is robust causal interpretation then we can do something more informative. Uncertainty, in the specification of three confounding parameters can be propagated through an equation to produce a confounding interval. Here, we develop supporting mathematical theory and describe an example application. Our proposed methodology applies well to studies of a continuous response or rare outcome. It is a general method for quantifying error from model uncertainty. Whereas, confidence intervals are used to assess uncertainty from unmeasured individuals, confounding intervals can be used to assess uncertainty from unmeasured attributes.

P638 Stenotic Crohn’s disease

Background The treatment of Crohn’s stenosis appears to be codified and complex, it depends on the inflammatory or fibrous type of stenosis. The purpose of our study was to describe the clinical, epidemiological and therapeutic characteristics of Crohn’s disease in its stenotic form and to determine the failure factors for the treatment of stenotic CD. Methods This is a descriptive and analytical monocentric retrospective study, involving 900 Crohn’s patients, 189 of whom had stenotic CD. The statistical analysis is performed using the SPSS 22.0 software. Results The average age was 32± 11 years. Followed for an average of 48 months[12–96].Sex ratio=1.14F/1H. 44(23.3%) were smokers and 29(15.3%) had a previous of appendectomy.Symptomatology was Koenig syndrome in 107 cases(56.6%), occlusive syndrome in 40 cases(21.2%), constipation in 31 cases(16.4%), vomiting in 7 cases(3.7%) and 4 cases(2.2%) asymptomatic.The localisation of stenosis was ileocaecal in 118 patients(62.4%), hail in 32 patients(16.9%), colic in 17 cases(9%), anal in 15 cases(7.9%) and high in 7 cases(3.7%).Stenosis was unique in 160 cases(84.7%) and multiple in 29 cases(15.3%). 117 patients (62%) had a short stenosis <5 cm and 72 patients (38%) had a stenosis >5 cm. The fibrous nature of stenosis was in 86 patients (45.5%) and inflammatory in 103 (54.5%). 40 patients (21.2%) had an associated fistulizing behaviour. Anoperineal manifestations (MAP) in 58 cases (30.7%). Therapeutically speaking:80 patients (42.3%) were treated with corticosteroids, 10 patients (5.3%) with anti-TNFa, 3 patients (1.6%) with immunosuppressants (IS), 12 cases (6.3%) with endoscopic dilation and 84 cases (44.4%) were operated. The course was marked by a good response in 53 cases (28%), the appearance of fistula± abscess in 25 cases (13.2%), intestinal obstruction in 13 cases (6.9%) and recurrence of stenotic disease in 98 cases (51.9%).There is a difference in management between fibrous and inflammatory stenosis:corticosteroids(1.2%vs98.8%),anti-TNF(10%vs90%), dilation(100%vs0%), surgery(84.5%vs15.5%), this difference is statistically significant(p < 0.001). In multivariate analysis and by adjusting for confounding parameters, it appears that only MAP, ileocaecal location and fistulizing behavior are associated with treatment failure with [OR = 3.2; IC = 1.4–7.7; p = 0.005], [OR = 0.17; IC = 0.3–0.9; p = 0.037], [OR = 2.6; IC = 1.02–6.6; p = 0.04]. Conclusion There was a statistically significant difference (p < 0.001) in terms of response to corticosteroid and anti-TNF treatments, as well as the use of surgery and dilatation between fibrous and inflammatory stenosis. And treatment failure was related to: MAP association [OR = 3.2; IC = 1.4–7.7; p = 0.005], ileocaecal localisation of stenosis [OR = 0.17; IC=0.3–0.9; p = 0.037] and fistulizing behavior[OR = 2.6;IC = 1.02–6.6;p = 0.04]

More pesticides—less children?

Summary A previously presented study investigated the impact of recent pesticide exposure on cytological signs of genotoxicity and on symptoms of intoxication in 71 male coffee workers in the Dominican Republic. An unexpected finding of this study was that conventional farming workers, among other symptoms, reported fewer children than controls working in organic farms without pesticide use. This study set out to investigate possible reasons for the latter difference. One statistical problem of this analysis is that the age of the workers is a strong predictor for the number of children and available data on the exposure determinants “duration of pesticide exposure” as well as “age at first pesticide exposure” are correlated with age. To correctly control statistics for these confounding parameters, different approaches to best control for age were explored. After careful elimination of the age-related confounding factors, a reduced number of children was still observed in exposed workers. The clearest effect is seen in those workers that reported first exposure before the age of 20 years. Socioeconomic factors could still confound that finding, but a direct effect of early life pesticide exposure is the most likely explanation of the observation.

Prevalence and Risk Factors of Discordance between Left- and Right-Hip Bone Mineral Density Using DXA

To determine the prevalence of significant left-right differences in hip bone mineral density (BMD), and the impact of this difference on osteoporosis diagnosis, we measured bilateral proximal femora using dual energy X-ray absorptiometry (DXA) in 3481 subjects (608 males, 2873 females). The difference between left and right hip was considered significant if it exceeded the smallest detectable difference (SDD) for any of the three hip subregions. Contralateral femoral BMD was highly correlated at all measuring sites (–0.95). However, significant left-right differences in BMD were common: the difference exceeded the SDD for 54% of patients at total hip, 52.1% at femoral neck, and 57.7% at trochanter. The prevalence of left-right differences was greater in participants >65 years. For 1169 participants with normal spines, 22 (1.9%) had discordant left-right hips in which one hip was osteoporotic; for 1349 patients with osteopenic spines, 94 (7%) had osteoporosis in one hip. Participants with BMI < 20 kg/m2 were more likely to show major T-score discordance (osteoporosis in one hip and normal BMD in the other). Multiple regression analysis showed that the only significant statically parameter that persists after adjusting for all potential confounding parameters were age over 65 years.