concentration patterns
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2022 ◽  
pp. 1420326X2110587
Author(s):  
Dadi Zhang ◽  
Er Ding ◽  
Philomena M. Bluyssen

Since the COVID-19 pandemic, the ventilation of school buildings has attracted considerable attention from the general public and researchers. However, guidance to assess the ventilation performance in classrooms, especially during a pandemic, is still lacking. Therefore, aiming to fill this gap, this study conducted a full-scale laboratory study to monitor the CO2 concentrations at 18 locations in a classroom setting under four different ventilation regimes. Additionally, a field study was carried out in two Dutch secondary schools to monitor the CO2 concentrations in the real classrooms with different ventilation regimes. Both the laboratory and field study findings showed that CO2 concentrations varied a lot between different locations in the same room, especially under natural ventilation conditions. The outcome demonstrates the need of monitoring the CO2 concentration at more than one location in a classroom. Moreover, the monitored CO2 concentration patterns for different ventilation regimes were used to determine the most representative location for CO2 monitoring in classrooms. For naturally ventilated classrooms, the location on the wall opposite to windows and the location on the front wall (nearby the teacher) were recommended. For mechanically ventilated classrooms, one measurement location seemed enough because CO2 was well-mixed under this ventilation regime.


PLoS ONE ◽  
2021 ◽  
Vol 16 (12) ◽  
pp. e0260626
Author(s):  
Maria Volodina ◽  
Nikolai Smetanin ◽  
Mikhail Lebedev ◽  
Alexei Ossadtchi

Meditation is a consciousness state associated with specific physiological and neural correlates. Numerous investigations of these correlates reported controversial results which prevented a consistent depiction of the underlying neurophysiological processes. Here we investigated the dynamics of multiple neurophysiological indicators during a staged meditation session. We measured the physiological changes at rest and during the guided Taoist meditation in experienced meditators and naive subjects. We recorded EEG, respiration, galvanic skin response, and photoplethysmography. All subjects followed the same instructions split into 16 stages. In the experienced meditators group we identified two subgroups with different physiological markers dynamics. One subgroup showed several signs of general relaxation evident from the changes in heart rate variability, respiratory rate, and EEG rhythmic activity. The other subgroup exhibited mind concentration patterns primarily noticeable in the EEG recordings while no autonomic responses occurred. The duration and type of previous meditation experience or any baseline indicators we measured did not explain the segregation of the meditators into these two groups. These results suggest that two distinct meditation strategies could be used by experienced meditators, which partly explains the inconsistent results reported in the earlier studies evaluating meditation effects. Our findings are also relevant to the development of the high-end biofeedback systems.


Animals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3369
Author(s):  
Janna Hinderer ◽  
Julia Lüdeke ◽  
Lisa Riege ◽  
Peggy Haimerl ◽  
Alexander Bartel ◽  
...  

Pregnancy and lactation are amongst the most challenging times of a bitch’s life. Most studies focusing on the endocrinological aspect of pregnancy consider only a small number of animals. The aim of this study was to evaluate progesterone (P4) concentrations in a large number of bitches during early, mid and late pregnancy. In total, 126 bitches of various breeds were recruited following a thorough clinical and gynecological examination during estrus. Blood samples were collected three times (T1–T3) during pregnancy or from non-pregnant dogs in diestrus, and P4 was measured via chemiluminescence. At T1 (11–19 days post-ovulation (dpo)), serum P4 concentrations were 30.23 ± 6.65 ng/mL and 28.45 ± 6.26 ng/mL, at T2 (23–32 dpo) they were 22.73 ± 6.27 ng/mL and 22.59 ± 5.77 ng/mL and at T3 (52–60 dpo) they were 6.68 ± 2.18 ng/mL and 3.17 ± 2.26 ng/mL, in pregnant (n = 98) and non-pregnant (n = 23) dogs respectively. The P4 concentrations differed significantly between pregnant and non-pregnant animals at the last examination (p ≤ 0.001). In the context of hypoluteoidism, the gathered data yielded interesting results. Overall, 28 out of 98 pregnant bitches showed a greater decline (>15 ng/mL) in P4 concentrations from early to mid-pregnancy, and 56 bitches showed P4 concentrations lower than deemed adequate (>20 ng/mL at T1 and T2, >5 ng/mL at T3) according to existing recommendations. Despite not being supplemented with P4, none of those animals suffered from abortion or preterm delivery. Considering that supplementation of P4 can entail considerable risks for the bitch and the puppies, more research on P4 concentration patterns, diagnosis of hypoluteoidism and treatment indications and options is indicated.


2021 ◽  
Author(s):  
Maria Volodina ◽  
Nikolai Smetanin ◽  
Mikhail Lebedev ◽  
Alexei Ossadtchi

Meditation is a consciousness state associated with specific physiological and neural correlates. Numerous investigations of these correlates reported controversial results which prevented a consistent depiction of the underlying neurophysiological processes. Here we investigated the dynamics of multiple neurophysiological indicators during a staged meditation session. We measured the physiological changes at rest and during the guided Taoist meditation in experienced meditators and naive subjects. We recorded EEG, respiration, galvanic skin response, and photoplethysmography. All subjects followed the same instructions split into 16 stages. In the experienced meditators group we identified two subgroups with different physiological markers dynamics. One subgroup showed several signs of general relaxation evident from the changes in heart rate variability, respiratory rate, and EEG rhythmic activity. The other subgroup exhibited mind concentration patterns primarily noticeable in the EEG recordings while no autonomic responses occurred. The duration and type of previous meditation experience or any baseline indicators we measured did not explain the segregation of the meditators into these two groups. These results suggest that two distinct meditation strategies could be used by experienced meditators, which partly explains the inconsistent results reported in the earlier studies evaluating meditation effects. Our findings are also relevant to the development of the high-end biofeedback systems.


2021 ◽  
pp. 1-8
Author(s):  
Marwa Brahmi ◽  
Moufida Atigui ◽  
Ihmen Hammadi ◽  
Jacques Portanguen ◽  
Mohamed Hammadi ◽  
...  

Abstract This research paper addresses the hypothesis that oxytocin (OT) could be released during suckling and during milking with and without the presence of a calf and that this release could be regulated by maternal behaviour. Plasma concentration patterns of OT and cortisol (CORT) were measured in six Tunisian dromedary camels during 2 suckling episodes, 2 manual milking episodes with calves beside the mother and 2 machine milking episodes without calves present. Various patterns of OT release were observed between each camel including specific two peak release patterns. Higher plasma OT concentrations were found during the suckling and hand-milking episodes with simultaneous suckling of calves, than during the machine milking episodes without calves. Exclusive mechanical milking episodes also evoked significant mean OT release, although greatly reduced compared to suckling and hand milking. The low basal levels and classical CORT release patterns suggested non-stressful management practices were used and there were very limited differences in udder stimulation between managements. The OT release induced by exclusive suckling and suckling together with hand-milking gives a reference point for what a good milk ejection stimulation is in camels. The important and specific reduction of OT release during machine milking without the calf present could be a physiological consequence of the maternal behaviour (selectivity for the own young) and to a lesser extent explained by a lower stimulation by machine milking.


Erdkunde ◽  
2021 ◽  
Vol 75 (2) ◽  
pp. 105-120
Author(s):  
Antoni Domènech ◽  
Aaron Gutiérrez ◽  
Josep-Maria Arauzo-Carod

The article analyses the uneven geography of foreclosed housing owned by large private landlords in Catalonia. A Negative Binomial Model is applied to identify the local determinants of the concentration patterns of 32,941 housing units in Catalan cities. Indicators of socioeconomic vulnerability, such as the percentage of foreign population or the percentage of unemployed residents, are identified as key explanatory factors of the regional geography of housing accumulated by banks which, in turn, correspond to areas in which global corporate landlords are focusing their business for profiteering from the rental market in the current expansionist phase of the housing cycle. Our findings demonstrate that the concentration of properties in the most vulnerable areas was fuelled by foreclosures responsibility of banks rescued with public funds. In tandem, we provide detailed information for the understanding of the new scenarios that have emerged during the post-crisis phase.


Author(s):  
Ayako Chan-Hosokawa ◽  
Jolene J Bierly

Abstract Prior to 2017, heroin and other prescription opioids were the most prevalent opioids implicated in driving under the influence of drugs (DUID) investigation cases and fentanyl was rarely included in the scope of toxicological analysis. Fentanyl has become the most frequently identified opioid in DUID cases with many suspected heroin cases turning out to be only fentanyl. A review of fentanyl positive DUID cases at NMS Labs was performed to provide prevalence information, change in concentration, patterns of combined drug use, indicators of impairment, and driving behavior in order to assist with toxicological interpretation of DUID scenarios involving fentanyl. Fentanyl positive DUID cases received between January 2010 and December 2020 were examined. Blood results were confirmed and quantitated for fentanyl, norfentanyl and acetylfentanyl using a liquid chromatography–tandem mass spectrometry (LC–MS-MS) analysis with a limit of quantitation (LOQ) of 0.10, 0.20 and 0.10 ng/mL, respectively. Of 153,234 blood cases examined for DUID over 11 years, fentanyl confirmed positive in 6,779 (4.4%) cases. However, there were significant changes in positivity over time. Fentanyl percent positivity increased from 0.60% in 2010 to 12% in 2020. Of 5,976 confirmed fentanyl positive cases in 2018 through 2020, blood concentrations greater than 4.0 ng/mL were observed in 44% (2018), 55% (2019), and 59% (2020) of cases. Polypharmacy was common with 87% of blood samples confirming positive for fentanyl and at least one other compound. Stimulants was the most commonly identified drug class in cases where at least one additional drug class was present. This study illustrates the importance of including fentanyl in a routine blood DUID panel.


Author(s):  
Larissa Montas ◽  
Alesia Ferguson ◽  
Kristina Mena ◽  
Helena Solo-Gabriele ◽  
Claire B. Paris

ABSTRACT Marine oil spill incidents create concerns about human health risks, particularly in nearshore locations such as beaches used for recreation. To improve the timeliness of risk estimates during an oil spill, we need to expand modelling capacity for oil spill chemicals (OSCs) from predictions for chemical bulk measurements such as Total Petroleum Hydrocarbons (TPH) to predictions of individual concentrations of the more toxic Polycyclic Aromatic Hydrocarbons (PAH)s. The objective of this study is to establish a relationship for TPH and PAH nearshore sampling concentration values with the oil mass landing and TPH hindcast from a 3D Hydrodynamic Fate and Transport Model (3D-FTM) for a past oil spill. The overall goal is to use this information to expand current modeling capacities to predict concentration distributions for individual PAHs as a starting point for health risk assessment. During Phase I of this study, historic sampling data for various matrices (weathered oil, seawater and sediments) were used to evaluate PAH concentration distributions within time-space specific categories. The categories corresponded to samples collected prior to nearshore oiling, post nearshore oiling and at no time impacted by oil as predicted by historic oil spill trajectories. For matrices within each category, concentration frequency distributions and concentration patterns were generated for a subset of PAHs. Results show differences in PAH concentration patterns within each matrix and for each category. Concentration frequency distributions for most PAHs in each category were log-normally distributed. Phase II is ongoing. Here we analyze PAH and TPH concentrations measured from surface weathered oil slick samples collected at the time of the Deepwater Horizon (DWH) oil spill. Preliminary results show that concentrations for a subset of PAHs in weathered oil slicks correlate well with TPH concentrations (R2=0.76). We are collocating the historic environmental sampling data with the output from the Oil-Connectivity Modelling System (Oil-CMS). The relationship between measured and model predicted TPH is explored by comparing values for samples that coincide in time and space with the model's particles. A subsequent step is to use output of the oil-CMS in combination with the physical and chemical properties for each PAH to predict concentration distributions for individual PAHs. The overarching goal is to improve risk estimates and, therefore, better guide public health decision-making.


2020 ◽  
Vol 13 (8) ◽  
pp. 4601-4617
Author(s):  
Bas Mijling

Abstract. In many cities around the world people are exposed to elevated levels of air pollution. Often local air quality is not well known due to the sparseness of official monitoring networks or unrealistic assumptions being made in urban-air-quality models. Low-cost sensor technology, which has become available in recent years, has the potential to provide complementary information. Unfortunately, an integrated interpretation of urban air pollution based on different sources is not straightforward because of the localized nature of air pollution and the large uncertainties associated with measurements of low-cost sensors. This study presents a practical approach to producing high-spatiotemporal-resolution maps of urban air pollution capable of assimilating air quality data from heterogeneous data streams. It offers a two-step solution: (1) building a versatile air quality model, driven by an open-source atmospheric-dispersion model and emission proxies from open-data sources, and (2) a practical spatial-interpolation scheme, capable of assimilating observations with different accuracies. The methodology, called Retina, has been applied and evaluated for nitrogen dioxide (NO2) in Amsterdam, the Netherlands, during the summer of 2016. The assimilation of reference measurements results in hourly maps with a typical accuracy (defined as the ratio between the root mean square error and the mean of the observations) of 39 % within 2 km of an observation location and 53 % at larger distances. When low-cost measurements of the Urban AirQ campaign are included, the maps reveal more detailed concentration patterns in areas which are undersampled by the official network. It is shown that during the summer holiday period, NO2 concentrations drop about 10 %. The reduction is less in the historic city centre, while strongest reductions are found around the access ways to the tunnel connecting the northern and the southern part of the city, which was closed for maintenance. The changing concentration patterns indicate how traffic flow is redirected to other main roads. Overall, it is shown that Retina can be applied for an enhanced understanding of reference measurements and as a framework to integrate low-cost measurements next to reference measurements in order to get better localized information in urban areas.


2020 ◽  
Vol 35 (8) ◽  
pp. 889-899
Author(s):  
Fato Fene ◽  
Edson Serván-Mori ◽  
Miguel Ángel Mendoza ◽  
Carlos Chivardi ◽  
Hortensia Reyes-Morales ◽  
...  

Abstract ‘Social efficiency’ (SE) denotes the capacity of health systems to ensure equitable access to quality health services at no financial risk to users. Mexico and other low- and middle-income countries have rarely studied the performance of their health systems from an SE perspective. We propose a metric for assessing SE in the production of maternal health services in the public sector among populations without social security, analysing contextual correlates of the demand for these services. Analysis was based on administrative data collected from the 243 health jurisdictions (HJs) in Mexico for the period 2008–15. We defined production inputs as the availability of physical and human resources and social product as the unweighted sum of social sub-products, including an equitable distribution of maternal health resources, the provision of quality maternal health care and financial protection for users. We described the SE scores, the main contextual characteristics as well as those related to the demand for maternal health services. We then performed a variance decomposition analysis of the SE score by component and estimated the SE territorial concentration patterns. Finally, we identified the structural characteristics modelling SE by means of a spatial autoregressive panel data model with fixed effects by year. The SE score rose from 57.7% in 2008 to 71.9% in 2015 (P < 0.01), with its quality component accounting for the largest proportion of variance (30%). SE peaked in HJs with low social marginalization and rurality, and with service demand characterized by low parity and older populations. Different SE levels demonstrated territorial concentration patterns. Analysing SE as a metric for health system performance offers elements that contribute to the achievement of UHC as well as to the design and implementation of effective maternal health interventions intended particularly for the most socially vulnerable sectors of the population.


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