Is life going too fast? Exploring the unique and joint contributions of mindfulness, temperament, task load, and metacognitions about time.

BACKGROUND: Previous research has shown that mindfulness is associated with slower passage of time in everyday life, and with lower self-reported time pressure. This study investigates some of the potential mechanisms behind these relationships. METHODS: 318 participants submitted their responses to an online survey which collected data regarding passage of time judgments, time pressure, trait mindfulness, temperament, task load, and metacognitions about time. Using commonality and dominance analyses, we explored how these variables contributed, either alone or jointly, to predicting how fast (or slow) time seems to pass for participants, or how pressed for time they felt. RESULTS: Mindfulness and temperament had some overlaps in their ability to predict passage of time judgments and time pressure for durations at the month and 2-month scales. The temperamental trait of extraversion/surgency, as well as the Non-judging and Non-reacting facets of mindfulness were among the best predictors of passage of time judgments and time pressure. Attention-related variables were mainly related to time perception via their involvement in joint effects with other variables. Results also suggested that metacognitions about time interacted with other variables in predicting passage of time judgments, but only at the month scale. Finally, among all the variables included in this study, task load had the highest degree of involvement in predictions of self-reported time pressure at the week and month scales, but it contributed relatively little to predicting passage of time judgments. CONCLUSIONS: Results suggest that mindfulness relates to passage of time through its involvement in inferential processes. The data also shows how different factors are related to PoTJ at different time scales. Finally, results suggest the existence of both similarities and differences in how passage of time and time pressure relate to the other included variables.

Status-dependent metabolic effects of social interactions in a group-living fish.

Social interactions can sometimes be a source of stress, but social companions can also ameliorate and buffer against stress. Stress and metabolism are closely linked, but the degree to which social companions modulate metabolic responses during stressful situations-and whether such effects differ depending on social rank-is poorly understood. To investigate this question, we studied Neolamprologus pulcher, a group-living cichlid fish endemic to Lake Tanganyika and measured the metabolic responses of dominant and subordinate individuals when they were either visible or concealed from one another. When individuals could see each other, subordinates had lower maximum metabolic rates and tended to take longer to recover following an exhaustive chase compared with dominants. In contrast, metabolic responses of dominants and subordinates did not differ when individuals could not see one another. These findings suggest that the presence of a dominant individual has negative metabolic consequences for subordinates, even in stable social groups with strong prosocial relationships.

Using heart rate and acceleration biologgers to estimate winter activity costs in free-swimming largemouth bass.

Winter is a critical period for largemouth bass (Micropterus nigricans) with winter severity and duration limiting their population growth at northern latitudes. Unfortunately, we have an incomplete understanding of their winter behaviour and energy use in the wild. More winter-focused research is needed to better understand their annual energy budget, improve bioenergetics models, and establish baselines to assess the impacts of climate warming; however, winter research is challenging due to ice cover. Implantable tags show promise for winter-focused research as they can be deployed prior to ice formation. Here, using swim tunnel respirometry, we calibrated heart rate and acceleration biologgers to enable estimations of metabolic rate (MO2) and swimming speed in free-swimming largemouth bass across a range of winter-relevant temperatures. In addition, we assessed their aerobic and swim performance. Calculated group thermal sensitivities of most performance metrics indicated the passive physicochemical effects of temperature, suggesting little compensation in the cold; however, resting metabolic rate and critical swimming speed showed partial compensation. We found strong relationships between acceleration and swimming speed, as well as between MO2 and heart rate, acceleration, or swimming speed. Jackknife validations indicated that these modeled relationships accurately estimate swimming speed and MO2 from biologger recordings. However, there were relatively few reliable heart rate recordings to model the MO2 relationship. Recordings of heart rate were high-quality during holding but dropped during experimentation, potentially due to interference from aerobic muscles during swimming. The models informed by acceleration or swimming speed appear to be best suited for field applications.

Mindfulness and time perception: A systematic integrative review.

Several recent studies have explored the relationships between mindfulness and time perception, an area of research that has become increasingly popular in the last 10-15 years. In this article, we present a systematic integrative review of the evidence on this subject. We also integrate the field's findings into a conceptual framework which considers the multifaceted nature of both mindfulness, and time perception research. To identify the relevant literature, we searched the following databases using relevant keywords: PsycINFO; Medline; EBSCO Host Psychology and Behavioral Sciences Collection; and Web of Science. These searches were last performed on the 4th of May 2022, and additional hand searches were also conducted. To be included, articles had to be in English and contain original data about the potential relationship(s) between mindfulness and time perception. Articles which did not present usable data about the relationship(s) between the variables of interest were excluded. In total, 47 research articles were included in the review (combined sample size of ∼5800 participants). Risks of bias in the selected studies were evaluated using two separate assessment tools designed for this purpose. Through an integrative narrative synthesis, this article reviews how mindfulness may relate to time perception for various reference frames, and for various time perception measures and methods. It also provides new insights by exploring how a wide range of findings can be integrated into a coherent whole, in light of some relevant time perception models and mindfulness theories. Altogether, the reviewed data suggest the existence of complex and multifaceted relationships between mindfulness and time perception, highlighting the importance of considering many factors when planning research or interpreting data in this field. Limitations of the current review include the scarceness of data for certain categories of findings, and the relatively low prevalence of studies with a randomized controlled design in the source literature. This research was partly funded by a grant from the Natural Science and Engineering Research Council of Canada.

An ex vivo approach to the differential parenchymal responses induced by cigarette whole smoke and its vapor phase.

Using a rat lung slice model, this study compared the stress responses induced by cigarette whole smoke (WS) to that induced by the vapor phase (VP) of the smoke. Following a 3-day exposure, lung slices exposed to 4, 10 and 20% WS retained 85, 42 and 16% relative survival respectively in comparison to the air-exposed ones. Consistently, histological observations revealed concentration-related alveolar damages in the lung slices. Expression of 5 stress-response genes was examined following a single 30 min exposure to 4% WS or VP. WS exposure resulted in 4, 11 and 50-fold induction of IL-1ß, kinin type I receptor (B1R) and CYP1A1 genes, respectively, while CYP1B1 and TNF-α genes expression was found only two times higher in comparison to VP group. Since cigarette WS consists of particulate and vapor phases, these results highlight the preferential or synergistic role of the particulate phase in the induction of IL-1ß, B1R and CYP1A1 genes and that VP did not have comparable effects on expression of these genes. However, both phases fairly contributed to the induction of CYP1B1 and TNF-α genes. VP was the fraction responsible for the toxic effect since WS did not produce further toxicity. The 4% whole smoke deposited about 7.1 µg/cm² of total particulate matter (TPM) to the exposure chamber which may account for observed differential stress responses in the lung slices.

Cigarette smoke-induced kinin B1 receptor promotes NADPH oxidase activity in cultured human alveolar epithelial cells.

Pulmonary inflammation is an important pathological feature of tobacco smoke-related lung diseases. Kinin B1 receptor (B1R) is up-regulated in the rat trachea chronically exposed to cigarette-smoke. This study aimed at determining (1) whether exposure to total particulate matter of the cigarette smoke (TPM) can induce B1R in human alveolar epithelial A549 cells, (2) the mechanism of B1R induction, (3) the functionality of de novo synthesized B1R, and (4) the role of B1R in TPM-induced increase of superoxide anion (O2(●⁻)) level. Results show that A549 cells exposed to 10 µg/ml TPM increased O2(●⁻) level along with B1R (protein and mRNA) and IL-1ß mRNA. In contrast, B2R and TNF-α mRNA were not affected by TPM. The increasing effect of TPM on O2(●⁻) level was not significantly affected by the B1R antagonist SSR240612. TPM-increased B1R mRNA was prevented by co-treatments with N-acetyl-l-cysteine (potent antioxidant), diphenyleneiodonium (NADPH oxidase inhibitor), IL-1Ra (interleukin-1R antagonist) and SN-50 (specific inhibitor of NF-kB activation) but not by pentoxifylline (TNF-α release inhibitor), indomethacin and niflumic acid (COX-1 and -2 inhibitors). Stimulation of B1R with a selective agonist (des-Arg9-BK, 10 µM; 30 min) increased O2(●⁻)production which was prevented by apocynin and diphenyleneiodonium (NADPH oxidase inhibitors). Data suggest that the increased expression of B1R by TPM in A549 cells is mediated by oxidative stress, IL-1ß and NF-kB but not by cyclooxygenases or TNF-α. The amplification of O2(●⁻) levels via the activation of B1R-NADPH oxidase may exacerbate pulmonary inflammation and contribute to the chronicity of tobacco smoke-related lung diseases.

Headspace stir bar sorptive extraction-gas chromatography/mass spectrometry characterization of the diluted vapor phase of cigarette smoke delivered to an in vitro cell exposure chamber.

Advanced smoke generation systems, such as the Borgwaldt RM20S(®) smoking machine used in combination with the BAT exposure chamber, allow for the generation, dilution and delivery of fresh cigarette smoke to cell or tissue cultures for in vitro cell culture analyses. Recently, our group confirmed that the Borgwaldt RM20S(®) is a reliable tool to generate and deliver repeatable and reproducible exposure concentrations of whole smoke to in vitro cultures. However, the relationship between dose and diluted smoke components found within the exposure chamber has not been characterized. The current study focused on the development of a headspace stir bar sorptive extraction (HSSE) method to chemically characterize some of the vapor phase components of cigarette smoke generated by the Borgwaldt RM20S(®) and collected within a cell culture exposure chamber. The method was based on passive sampling within the chamber by HSSE using a Twister™ stir bar. Following exposure, sorbed analytes were recovered using a thermal desorption unit and a cooled injection system coupled to gas chromatograph/mass spectrometry for identification and quantification. Using the HSSE method, sixteen compounds were identified. The desorption parameters were assessed using ten reference compounds and the following conditions led to the maximal response: desorption temperature of 200°C for 2 min with cryofocussing temperature of -75°C. During transfer of the stir bars to the thermal desorption system, significant losses of analytes were observed as a function of time; therefore, the exposure-to-desorption time interval was kept at the minimum of 10±0.5 min. Repeatability of the HSSE method was assessed by monitoring five reference compounds present in the vapor phase (10.1-12.9% RSD) and n-butyl acetate, the internal standard (18.5% RSD). The smoke dilution precision was found to be 17.2, 6.2 and 11.7% RSD for exposure concentrations of 1, 2 and 5% (v/v) cigarette vapor phase in air, respectively. A linear response of analyte abundance was observed as a function of dilution. Extrapolation to 100% (v/v) cigarette vapor phase, i.e., undiluted smoke, gave yields for the five compounds ranging from 6 to 450 ng for 10 min exposure.

Estimation and correlation of cigarette smoke exposure in Canadian smokers as determined by filter analysis and biomarkers of exposure.

A clinical study conducted in Canada compared two methods of estimating exposure to cigarette smoke in 192 volunteer subjects: 43 smokers of 4-6 mg, 49 of 8-12 mg and 50 of 14-15 mg ISO tar yield cigarettes and 50 non-smokers. Estimates of mouth level exposure (MLE) to nicotine, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), pyrene and acrolein were obtained by chemical analysis of spent cigarette filters. Estimates of smoke constituent uptake were achieved by analysis of urinary biomarkers for total nicotine equivalents (nicotine, cotinine, trans-3'-hydroxycotinine plus their glucuronide conjugates), NNK (total 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) plus glucuronide), pyrene (1-hydroxy pyrene plus glucuronide) and acrolein (3-hydroxylpropyl-mercapturic acid) plus the nicotine metabolite cotinine in plasma and saliva. The objective of our study was to confirm the correlations between measures of human exposure obtained by filter analysis and biomarkers. Significant correlations (p<0.001) were found between MLE and the relevant biomarker for each smoke constituent. The adjusted values of the Pearson correlation coefficients (r) were 0.80 (nicotine), 0.77 (acrolein) and 0.44 (pyrene). NNK correlations could not be obtained because of the low NNK yield of Canadian cigarettes. Unexpectedly high levels of acrolein biomarker found in non-smokers urine on one of the two days sampled emphasised the need for more than one sampling occasion per period and an awareness of non-tobacco sources of smoke constituents under investigation. No consistent dose response, in line with ISO tar yield smoked, of MLE estimates was found for nicotine, pyrene and acrolein and respective biomarkers. The influence of demographics on our results has also been examined.

Evaluation of precision and accuracy of the Borgwaldt RM20S(®) smoking machine designed for in vitro exposure.

The Borgwaldt RM20S(®) smoking machine enables the generation, dilution, and transfer of fresh cigarette smoke to cell exposure chambers, for in vitro analyses. We present a study confirming the precision (repeatability r, reproducibility R) and accuracy of smoke dose generated by the Borgwaldt RM20S(®) system and delivery to exposure chambers. Due to the aerosol nature of cigarette smoke, the repeatability of the dilution of the vapor phase in air was assessed by quantifying two reference standard gases: methane (CH(4), r between 29.0 and 37.0 and RSD between 2.2% and 4.5%) and carbon monoxide (CO, r between 166.8 and 235.8 and RSD between 0.7% and 3.7%). The accuracy of dilution (percent error) for CH(4) and CO was between 6.4% and 19.5% and between 5.8% and 6.4%, respectively, over a 10-1000-fold dilution range. To corroborate our findings, a small inter-laboratory study was carried out for CH(4) measurements. The combined dilution repeatability had an r between 21.3 and 46.4, R between 52.9 and 88.4, RSD between 6.3% and 17.3%, and error between 4.3% and 13.1%. Based on the particulate component of cigarette smoke (3R4F), the repeatability (RSD = 12%) of the undiluted smoke generated by the Borgwaldt RM20S(®) was assessed by quantifying solanesol using high-performance liquid chromatography with ultraviolet detection (HPLC/UV). Finally, the repeatability (r between 0.98 and 4.53 and RSD between 8.8% and 12%) of the dilution of generated smoke particulate phase was assessed by quantifying solanesol following various dilutions of cigarette smoke. The findings in this study suggest the Borgwaldt RM20S(®) smoking machine is a reliable tool to generate and deliver repeatable and reproducible doses of whole smoke to in vitro cultures.

Mechanism of cigarette smoke-induced kinin B(1) receptor expression in rat airways.

Pulmonary inflammation is an important pathological feature of tobacco smoke related lung diseases such as chronic obstructive pulmonary disease (COPD). Kinin type 1 and type 2 receptors (B(1)R, B(2)R) are known to be associated with inflammatory responses of the lungs and other organs. In this study, we investigated whether cigarette smoke-induced airway inflammation could up-regulate B(1)R and B(2)R in correlation with IL-1ß and TNF-α. Rat lung slices treated with 5 µg/ml total particulate matter (TPM) of cigarette smoke for 24 h showed an enhanced expression of B(1)R and IL-1ß by 5-fold and 30-fold, respectively, in comparison to vehicle treatment (dimethyl sulfoxide). However, higher concentrations of TPM failed to induce B(1)R. No significant increase of B(2)R or TNF-α gene induction was observed. IL-1 receptor antagonist (IL-1Ra, 2 ng/ml) significantly blocked B(1)R gene induction by TPM, while 500 µM pentoxifylline, TNF-α inhibitor, reduced it partially. Western blot analysis showed a 2-fold enhanced expression of B(1)R in rat lung slices treated with 5 µg/ml TPM for 24 h and such protein expression was totally blocked by a co-treatment with IL-1Ra but not with pentoxifylline. In addition to the lower airways, rat trachea subchronically exposed to cigarette whole smoke exhibited 11-fold B(1)R gene induction in comparison with those exposed only to air. Our results demonstrate the involvement of B(1)R in cigarette smoke-induced airway inflammation through a mechanism which is mediated by the pro-inflammatory cytokine IL-1ß.

Sequential fractionation with concurrent chemical and toxicological characterization of the combustion products of chlorogenic acid.

Chlorogenic acid is the most abundant polyphenol found in the tobacco plant. The biological effects of its combustion products remain largely unknown. In this study, chlorogenic acid was burned at 640 degrees C for 2 min and the particulate matter of the smoke was collected onto Cambridge filter pads followed by selective extraction in five different solvents. Various fractions of the chlorogenic acid combustion products were tested for induction of micronuclei in V79 Chinese hamster fibroblast cells. Over 40 compounds were identified in the dimethyl sulfoxide (DMSO) extract by high-performance liquid chromatography coupled to electrospray time-of-flight mass spectrometry (HPLC/TOF-MS). The DMSO extract was then fractionated into three major fractions by preparative LC. The fraction inducing the highest degree of toxicity was further separated into four sub-fractions. The sub-fraction responsible for the most toxic response was determined to contain catechol as its major component. The overall reproducibility of the combustion, the extraction procedure and the chemical characterization of the compounds responsible for the toxicity in the chlorogenic acid smoke were evaluated by LC/TOF-MS.

Dynamic MRI of larynx and vocal fold vibrations in normal phonation.

Dynamic magnetic resonance imaging (MRI) of the larynx and vocal folds during phonation was used for measuring the vertical laryngeal movements and the glottal angle of the vocal folds opening and closing in dynamic phase. The data used in this analysis were taken on 10 healthy volunteers during maximal inspiration and the prolonged phonation of the vowels [i] (as in key), [a] (as in car), [u] (as in loop), and the consonant [sh] (as in ship). The results of our MRI data have demonstrated the difference of the vocal folds movement in relation to the vowel and consonant sounds, with a large glottal opening for [sh] and a narrow opening for [i] and [u], and the difference of the laryngeal position in relation to the vowels, with [a] and [u] having a lower larynx position than [i]. Imaging the larynx's positions and the vocal folds' vibrations is possible using dynamic MRI. This technique permits measurements of laryngeal structures and glottal parameters in dynamic function with multiplanar high-resolution imaging. Analysis of laryngeal activity and vocal folds' vibration may be helpful for the evaluation of the phonation function and for the understanding of the physiology of vocal production and voice modulation.

Saber, ciência, ação / Savoir, science, action

Nesta obra, os autores propõem um conceito de ciência mais aberto à complexidade do real. Defendem uma metodologia multirreferencial, para que os profissionais se tornem cientistas capazes de contribuir para o saber nas ciências humanas e sociais, graças aos princípios e lições de vida extraídas de seu engajamento social.

Anatomical variations of the hepatic artery: study of 932 cases in liver transplantation.

The aim of this study was to identify and to classify anatomical hepatic artery (HA) variations concerning 932 HA dissections in liver transplantation (LT). Normal HA distribution was found in 68.1%. Variations of HA were detected in 31.9% and were divided into three groups describing 48 common hepatic artery (CHA) anomalies, 236 left or right hepatic artery (RHA) anomalies and 13 rare variations including one case of RHA stemmed from the inferior mesenteric artery and one case of normal CHA passed behind the portal vein. The authors propose a modified classification for HA anomalies which are based on the origin of the hepatic arterial supply (either by the CHA as the only source of the arterial vascularization or by additional or replaced right and left arteries) in order to improve management of liver disease thus as in LT.

In vitro bioactivity of combustion products from 12 tobacco constituents.

Twelve chemical components of tobacco leaf, representing 50% of its dry weight, were individually combusted and the bioactivities of their combustion products i.e. total particulate matter (TPM) were assayed using three in vitro tests. These components included carbohydrates, amino acids, proteins, polyphenols and carboxylic acids. The mutagenic potencies were assessed with the Salmonella mutagenicity assay (S. typhimurium TA98 and TA100). The induction of chromosomal damage, determined with the micronucleus test (IVMNT), and the neutral red uptake cytotoxicity test (NRU), were conducted on V79 hamster lung fibroblast cells. The Salmonella mutagenicity test and IVMNT were conducted with and without rat liver microsomal S9 fraction. Salmonella mutagenicity data confirmed the mutagenicity of TPM samples obtained from nitrogenous compounds (amino acids and proteins). The IVMNT showed that precursors of phenols in smoke (i.e. polyphenols) exhibited significantly higher levels of toxicity compared to other tobacco components. While S9 activation amplified the Salmonella mutagenicity response to combustion products, it significantly inhibited the toxicity measured with the IVMNT. NRU data demonstrated the increasing cytotoxicity induced following longer exposure time to TPM samples from nitrogenous and phenolic components. This study is the first to characterize the toxicity of the combustion products of major tobacco constituents. Our data suggest different mechanisms of toxicity and underline the relevance of using various bioassays.

Effects of volatile aromatics, aldehydes, and phenols in tobacco smoke on viability and proliferation of mouse lymphocytes.

Thirteen chemicals present in tobacco smoke were assessed for their effect on viability and proliferation of mouse lymphocytes in vitro. Acetaldehyde, benzene, butyraldehyde, isoprene, styrene, and toluene produced no effect on either viability or proliferation after 3 h of exposure. Formaldehyde, catechol, acrylonitrile, propionaldehyde, and hydroquinone significantly inhibited T-lymphocyte and B-lymphocyte proliferation with IC50 values ranging from 1.19 x 10(-5) M to 8.20 x 10(-4) M after 3 h of exposure. Acrolein and crotonaldehyde not only inhibited T-cell and B-cell proliferation, but also acted on viability with IC50 values ranging from 2.06 x 10(5) M to 4.26 x 10(-5) M. Mixtures of acrolein, formaldehyde, and propionaldehyde or crotonaldehyde were tested and interactive effects at 0.5 and 1 x IC50 were observed. Two mixtures significantly inhibited T-cell proliferation when compared to the control at 0.1 x IC50 concentration. The present study shows that some chemicals known to be present in tobacco smoke exert an effect on lymphocyte viability and proliferation in vitro.