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Extensive research has elucidated the influence of the gut microbiota on human health and disease susceptibility and resistance. We review recent clinical and laboratory-based experimental studies associating the gut microbiota with certain human diseases. We also highlight ongoing translational advances that manipulate the gut microbiota to treat human diseases and discuss opportunities and challenges in translating microbiome research from and to the bedside.

Background Adolescence is a critical period for vaping onset. The purpose of this article was to examine the effect of the early stages of the COVID-19 pandemic period on youth vaping. Methods We used 3-year linked data from the COMPASS study, including 7585 Canadian (Quebec, Ontario) adolescents from which 1949 completed all three survey waves (pre-COVID-19 [2018, 2019] and online [2020] during the early pandemic period [May–July 2020]) and provided vaping data. Structural equation modeling (SEM) and difference-in-difference (DD) models were used to estimate pre-COVID-19 to initial COVID-19 pandemic period change (2019–2020) in vaping (monthly, weekly, daily) compared with 2018–2019 change to adjust for age-related effects. Models were adjusted for age of entry into the cohort and sociodemographic characteristics. Results In the SEM and DD models, the proportion of youth who were monthly and weekly vaping increased from 2018 to 2019 but decreased from 2019 to 2020; daily vaping increased across all waves. However, for all vaping outcomes modeled, the expected increases from the pre-COVID-19 wave (2019) to the initial COVID-19 period wave (2020) were lesser relative to the changes seen across the 2018 to 2019 waves. Conclusion The early stages of the COVID-19 pandemic period appear to be associated with a reduction in the proportion of youth who were monthly and weekly vapers in our adjusted longitudinal models. While daily vaping increased over this same period of time, the magnitude of the increase in our adjusted longitudinal models appears attenuated by the early stages of the pandemic. Implications This large prospective study of youth that included pre-pandemic data is unique in that we were able to identify that the early stages of the COVID-19 pandemic period was associated with a reduction in the proportion of youth who were monthly and weekly vapers in our adjusted longitudinal models. Conversely, the proportion of youth who were daily vaping increased over this same period of time, but the magnitude of the increase appears smaller than expected during the early stages of the pandemic in our adjusted longitudinal models. This study provides novel robust evidence that the patterns of vaping most aligned with onset and progression (i.e., monthly and weekly use) appear attenuated during the initial pandemic period.

Limited research examines changes in quantities of various forms of smoked/vaped cannabis among regular consumers, including emerging adults (EAs; 18 to 29) in Canada. This information is particularly relevant in the current context of emerging cannabis behaviors among EAs related to political amendments (legalization of cannabis), vaping-related lung illnesses (EVALI), and unprecedented pandemics (COVID-19). This study investigated the impact of legalizing recreational cannabis use in Canada, the EVALI epidemic, and the COVID-19 pandemic on the quantity of smoked/vaped forms of cannabis in relation to gender differences. EAs retrospectively self-reported the quantity of herb, hash, concentrates, joint size, and the number of joints and vaping cartridges in relation to three consecutive developments: pre-legalization, post-legalization; pre-EVALI, post-EVALI, pre-COVID-19, and during COVID-19. The quantity of herb use significantly increased among heavy users, and vaping quantity significantly increased among light users. Overall, an increasing incremental trend was observed in the average quantity of cannabis forms used over time. Males consumed higher quantities of all cannabis forms than females. More males than females reported using concentrates (p < 0.05). These findings reveal unique aspects of the amount of various cannabis forms smoked/vaped in relation to gender and provides preliminary evidence of cannabis consumption behaviors in relation to changing social and cultural contexts.

Pattern formation originates during embryogenesis by a series of symmetry-breaking steps throughout an expanding cell lineage. In Drosophila, classic work has shown that the embryo segmentation is established by morphogens within a syncytium, and the subsequent action of the gap, pair-rule, and segment polarity genes. This classic model however does not translate directly to species that lack a syncytium – such as C. elegans – where cell fate is specified by cell-autonomous cell lineage programs and their inter-signaling. Previous single-cell RNA-Seq studies in C. elegans have analyzed cells from a mixed suspension of cells from many embryos to study late differentiation stages, or individual early stage embryos to study early gene expression in the embryo. To study the intermediate stages of early and late gastrulation (28- to 102- cells stages) missed by these approaches, here we determine the transcriptomes of the 1- to 102-cell stage to identify 119 embryonic cell-states during cell-fate specification, including ‘equivalence-group’ cell identities. We find that gene expression programs are modular according to the sub-cell lineages, each establishing a set of stripes by combinations of transcription factor gene expression across the anAterior-posterior axis. In particular, expression of the homeodomain genes establishes a comprehensive lineage-specific positioning system throughout the embryo beginning at the 28-cell stage. Moreover, we find that genes that segment the entire embryo in Drosophila have orthologs in C. elegans that exhibit sub-lineage specific expression. These results suggest that the C. elegans embryo is patterned by a juxtaposition of distinct lineage-specific gene regulatory programs each with a unique encoding of cell location and fate. This use of homologous gene regulatory patterning codes suggests a deep homology of cell fate specification programs across diverse modes of development.

Thermosetting materials generated by photopolymerization are inherently highly crosslinked and suffer from significant shrinkage stress, are often brittle, and have a limited range of mechanical properties. Various classes of chain transfer agents (CTAs) have been investigated and developed to reduce the crosslinking density of photopolymers by terminating kinetic chains and initiating new chains in situ. Although CTAs are successful in manipulating the mechanical properties of photopolymers, they are traditionally consumed during the polymerization and are therefore required in high loadings (up to 20 wt% of total formulation). Moreover, traditional CTAs frequently contain sulfur which is malodorous and can create unstable formulations. Presented here is a catalytic, sulfur-free CTA that can be added in ppm quantities to exist-ing commercial monomer feedstocks to create photopolymers similar to those prepared using traditional CTAs, but at 10,000x lower loadings. These catalysts, which are based on macrocyclic cobaloximes, were found to tunably reduce the molecular weight of the kinetic chain proportional to catalyst loading. It was shown, using only commercial monomers, that this catalyst could reduce the glass transition temperature (Tg), rubbery modulus (E’rubbery), and stiffness.

Multifactorial sampling designs were used to determine the vertical distribution of ichthyoplankton at multiple temporal and spatial scales in New Zealand. Hypotheses concerning the vertical distribution of fish larvae were tested in the following: depth strata, surface, near-surface, mid-depth and deep, and near the substratum. The consistency of abundance patterns was examined at three sites separated by 2–20 km over 2 months. We also tested for differences in shallow water columns of two depths (20 and 40 m) and both day and night. Although peak abundance of total larval fish was found at upper and lower strata, regardless of total depth of the water column, consistent taxa specific patterns of vertical distribution were also found. Some taxa were most abundant at the surface (e.g. mullids, hemiramphids, and kyphosids), whereas others were found at multiple depths below the surface and throughout the water column, regardless of site, time or depth of water column (e.g. carangids, engraulids, clupeids, scombrids, sparids and pleuronectids). Some taxa were most abundant in shallow water columns (e.g. mullids, tripterygiids and gobiids). Rank abundance by depth stratum for non-surface dwelling species varied among sites and times. Diel vertical movements were detected, some taxa (e.g. clupeids, scombrids and bothids) that were most abundant at the surface at night whereas for other taxa this pattern was more variable (e.g. carangids). We conclude that diel depth-related patterns in shallow water columns will influence interactions among taxa and the importance of different transport mechanisms for larval transport.

Pattern formation originates during embryogenesis by a series of symmetry-breaking steps throughout an expanding cell lineage. InDrosophila, classic work has shown that the embryo segmentation is established by morphogens within a syncytium, and the subsequent action of the gap, pair-rule, and segment polarity genes. This classic model however does not translate directly to species that lack a syncytium – such asC. elegans– where cell fate is specified by cell-autonomous cell lineage programs and their inter-signaling. Previous single-cell RNA-Seq studies inC. eleganshave analyzed cells from a mixed suspension of cells from many embryos to study late differentiation stages, or individual early stage embryos to study early gene expression in the embryo. To study the intermediate stages of early and late gastrulation (28- to 102- cells stages) missed by these approaches, here we determine the transcriptomes of the 1- to 102-cell stage to identify 119 embryonic cell-states during cell-fate specification, including ‘equivalence-group’ cell identities. We find that gene expression programs are modular according to the sub-cell lineages, each establishing a set of stripes by combinations of transcription factor gene expression across the anterior-posterior axis. In particular, expression of the homeodomain genes establishes a comprehensive lineage-specific positioning system throughout the embryo beginning at the 28-cell stage. Moreover, we find that genes that segment the entire embryo inDrosophilahave orthologs inC. elegansthat exhibit sub-lineage specific expression. These results suggest that theC. elegansembryo is patterned by a juxtaposition of distinct lineage-specific gene regulatory programs each with a unique encoding of cell location and fate. This use of homologous gene regulatory patterning codes suggests a deep homology of cell fate specification programs across diverse modes of development.

Purpose of review In this review, we will discuss the current status and recent developments in precision medicine in chronic obstructive pulmonary disease (COPD) through the lens of treatable traits. Recent findings Although the term 'treatable traits' in the treatment of COPD is relatively recent, this concept has been used for many years if one considers interventions such as long-term oxygen therapy or alpha-1 antitrypsin replacement therapy. Recent advances have included expanding the definition of COPD to include a broader population of people with lower respiratory disease but not meeting the strict criteria for obstruction, advances in imaging to aid in the diagnosis and treatment of COPD, advances in understanding symptoms and exacerbations to define severity, using biomarkers to guide therapy and better understanding and addressing polymorbidity and frailty. In addition, there is a concerted effort to use these concepts to identify COPD patients earlier in the disease process wherein disease modification may be possible. Summary Focusing on subsets of patients with COPD with certain characteristics should lead to better outcomes and fewer adverse effects from treatment. Video abstract http://links.lww.com/COPM/A30.

Introduction Une meilleure compréhension des facteurs individuels associés à l’initiation à la cigarette électronique contribuerait à l’amélioration des mesures de prévention. Ainsi, cette étude vise à 1) relever les caractéristiques de départ associées à l’initiation à la cigarette électronique et 2) déterminer si des changements dans ces caractéristiques sont associés à l’initiation à la cigarette électronique chez les adolescents canadiens. Méthodologie Cette étude a utilisé les données de l’année 6 (2017-2018, année de référence) et de l’année 7 (2018-2019, année de suivi) de l’étude COMPASS. L’échantillon final comprenait 12 315 élèves de la 9e à la 11e année qui avaient déclaré ne jamais avoir essayé la cigarette électronique au cours de l’année de référence. Les renseignements fournis par les élèves portaient sur leurs caratéristiques individuelles, la consommation d’autres substances, les comportements scolaires, l’activité physique, les comportements sédentaires, les troubles du sommeil, les symptômes d’anxiété et de dépression, la régulation émotionnelle et l’épanouissement. Des modèles hiérarchiques faisant appel aux équations d’estimation généralisées (EEG), stratifiés selon le sexe, ont permis d’analyser l’association entre 1) les caractéristiques de départ et l’initiation à la cigarette électronique lors de l’année de suivi et 2) des changements dans les caractéristiques de départ et l’initiation à la cigarette électronique lors de l’année de suivi. Résultats Au total, 29 % des élèves qui n’avaient encore jamais essayé la cigarette électronique ont déclaré en avoir fait l’usage au moment du suivi. Les élèves de 10e et 11e année étaient proportionnellement moins nombreux à avoir essayé la cigarette électronique. La consommation d’autres substances, l’école buissonnière et le respect des directives en matière d’activité physique pendant l’année de référence ainsi que des changements vers ces comportements mesurés au moment du suivi ont été associés à l’initiation à la cigarette électronique à la fois chez les garçons et chez les filles. Certaines différences ont été observées entre les filles et les garçons. Conclusion Étant donné que d’autres comportements liés à la santé ont été associés à l’initiation à la cigarette électronique, les stratégies de prévention devraient cibler les combinaisons de comportements à risque pour la santé afin de prévenir l’usage de la cigarette électronique chez les jeunes. De plus, mettre en œuvre des approches en milieu scolaire au début ou pendant le premier cycle du secondaire serait certainement bénéfique.

Having a better understanding of individual factors associated with e-cigarette initiation can help improve prevention efforts. Therefore, this study aimed to (1) identify baseline characteristics associated with e-cigarette initiation, and (2) determine whether changes in these baseline characteristics were associated with e-cigarette initiation.This study used data from Year 6 (2017/18, baseline) and Year 7 (2018/19, follow-up) of the COMPASS study. The final sample included 12 315 students in Grades 9 to 11 who reported never having tried e-cigarettes at baseline. Students reported demographic information, other substance use, school behaviours, physical activity, sedentary behaviour, sleep, symptoms of anxiety and depression, and emotional regulation and flourishing scores. Hierarchical GEE models, stratified by gender, examined the association between (1) baseline characteristics and e-cigarette initiation at follow-up and (2) changes in baseline characteristics and e-cigarette initiation at follow-up.In total, 29% of students who had not yet initiated e-cigarette use reported initiating e-cigarette use at follow-up. Students in Grades 10 and 11 were less likely to initiate e-cigarette use. Other substance use, skipping school and meeting the physical activity guidelines at baseline and one-year changes to these behaviours were associated with e-cigarette initiation among both male and female students. Additionally, some differences were noted between females and males.Given that other health behaviours were associated with e-cigarette initiation, prevention approaches should target multiple health-risk behaviours to help prevent youth e-cigarette use. Additionally, school-based approaches may benefit by being implemented at the beginning of high school or in junior high school.Une meilleure compréhension des facteurs individuels associés à l’initiation à la cigarette électronique contribuerait à l’amélioration des mesures de prévention. Ainsi, cette étude vise à 1) relever les caractéristiques de départ associées à l’initiation à la cigarette électronique et 2) déterminer si des changements dans ces caractéristiques sont associés à l’initiation à la cigarette électronique chez les adolescents canadiens.Cette étude a utilisé les données de l’année 6 (2017-2018, année de référence) et de l’année 7 (2018-2019, année de suivi) de l’étude COMPASS. L’échantillon final comprenait 12 315 élèves de la 9e à la 11e année qui avaient déclaré ne jamais avoir essayé la cigarette électronique au cours de l’année de référence. Les renseignements fournis par les élèves portaient sur leurs caratéristiques individuelles, la consommation d’autres substances, les comportements scolaires, l’activité physique, les comportements sédentaires, les troubles du sommeil, les symptômes d’anxiété et de dépression, la régulation émotionnelle et l’épanouissement. Des modèles hiérarchiques faisant appel aux équations d’estimation généralisées (EEG), stratifiés selon le sexe, ont permis d’analyser l’association entre 1) les caractéristiques de départ et l’initiation à la cigarette électronique lors de l’année de suivi et 2) des changements dans les caractéristiques de départ et l’initiation à la cigarette électronique lors de l’année de suivi.Au total, 29 % des élèves qui n’avaient encore jamais essayé la cigarette électronique ont déclaré en avoir fait l’usage au moment du suivi. Les élèves de 10e et 11e année étaient proportionnellement moins nombreux à avoir essayé la cigarette électronique. La consommation d’autres substances, l’école buissonnière et le respect des directives en matière d’activité physique pendant l’année de référence ainsi que des changements vers ces comportements mesurés au moment du suivi ont été associés à l’initiation à la cigarette électronique à la fois chez les garçons et chez les filles. Certaines différences ont été observées entre les filles et les garçons.Étant donné que d’autres comportements liés à la santé ont été associés à l’initiation à la cigarette électronique, les stratégies de prévention devraient cibler les combinaisons de comportements à risque pour la santé afin de prévenir l’usage de la cigarette électronique chez les jeunes. De plus, mettre en œuvre des approches en milieu scolaire au début ou pendant le premier cycle du secondaire serait certainement bénéfique.Twenty-nine percent of students who had not yet initiated e-cigarette use reported initiating e-cigarette use at follow-up. Other substance use (i.e. alcohol, cannabis and cigarettes) was strongly associated with e-cigarette initiation. Students who met the Canadian physical activity guidelines were more likely to initiate e-cigarette use, and female students who met the screen time guidelines were less likely. Anxiety and depression were not significantly associated with e-cigarette initiation, but there was an association with higher emotional dysregulation for females and higher flourishing for males. The majority of students maintained their behaviours over time; results for changes from baseline were largely consistent with findings at baseline.Vingt-neuf pour cent des élèves qui n’avaient encore jamais essayé la cigarette électronique ont déclaré en avoir fait l’usage au moment du suivi. La consommation d’autres substances (alcool, cannabis et cigarettes) était fortement associée à l’initiation à la cigarette électronique. Les élèves qui respectaient les directives canadiennes en matière d’activité physique ont eu davantage tendance à commencer à utiliser la cigarette électronique et les filles qui respectaient les directives sur le temps passé devant un écran ont eu moins tendance à commencer à utiliser la cigarette électronique. Si l’initiation à la cigarette électronique n’était pas associée de façon significative avec l’anxiété et la dépression, elle était toutefois associée à un dérèglement émotionnel élevé chez les filles et à un épanouissement élevé chez les garçons. La majorité des élèves ont maintenu leurs comportements au fil du temps : les résultats concernant les changements par rapport à l’année de référence présentaient une forte concordance avec les observations se rapportant à l’année de référence.