BackgroundGiven the rapid development during the early years (0-4 years), an understanding of the health implications of physical activity is needed. The purpose of this systematic review was to examine the relationships between objectively and subjectively measured physical activity and health indicators in the early years.MethodsElectronic databases were originally searched in April, 2016. Included studies needed to be peer-reviewed, written in English or French, and meet a priori study criteria. The population was apparently healthy children aged 1 month to 59.99 months/4.99 years. The intervention/exposure was objectively and subjectively measured physical activity. The comparator was various volumes, durations, frequencies, patterns, types, and intensities of physical activity. The outcomes were health indicators ranked as critical (adiposity, motor development, psychosocial health, cognitive development, fitness) and important (bone and skeletal health, cardiometabolic health, and risks/harm). The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) framework was used to assess the quality of evidence for each health indicator by each study design.ResultsNinety-six studies representing 71,291 unique participants from 36 countries were included. Physical activity interventions were consistently (>60% of studies) associated with improved motor and cognitive development, and psychosocial and cardiometabolic health. Across observational studies, physical activity was consistently associated with favourable motor development, fitness, and bone and skeletal health. For intensity, light- and moderate-intensity physical activity were not consistently associated with any health indicators, whereas moderate- to vigorous-intensity, vigorous-intensity, and total physical activity were consistently favourably associated with multiple health indicators. Across study designs, consistent favourable associations with health indicators were observed for a variety of types of physical activity, including active play, aerobic, dance, prone position (infants; ≤1 year), and structured/organized. Apart from ≥30 min/day of the prone position for infants, the most favourable frequency and duration of physical activity was unclear. However, more physical activity appeared better for health. Evidence ranged from “very low” to “high” quality.ConclusionsSpecific types of physical activity, total physical activity, and physical activity of at least moderate- to vigorous-intensity were consistently favourably associated with multiple health indicators. The majority of evidence was in preschool-aged children (3-4 years). Findings will inform evidence-based guidelines.Electronic supplementary materialThe online version of this article (10.1186/s12889-017-4860-0) contains supplementary material, which is available to authorized users.

Please note that Figure 3 should read as follows (left-hand segment 24 and not 14; right-hand segment 37 and not 26): Figure 3. Venn diagram of proteins overlapping between the two trials and the number of proteins identified in each trial. Of the total proteins from the first and second trials, 76.9 and 68.4%, respectively, were common to both trials.

Gram-negative bacteria constitutively secrete outer membrane vesicles (OMVs) into the extracellular milieu. Recent research in this area has revealed that OMVs may act as intercellular communicasomes in polyspecies communities by enhancing bacterial survival and pathogenesis in hosts. However, the mechanisms of vesicle formation and the pathophysiological roles of OMVs have not been clearly defined. While it is obvious that mass spectrometry-based proteomics offers great opportunities for improving our knowledge of bacterial OMVs, limited proteomic data are available for OMVs. The present review aims to give an overview of the previous biochemical, biological, and proteomic studies in the emerging field of bacterial OMVs, and to give future directions for high-throughput and comparative proteomic studies of OMVs that originate from diverse Gram-negative bacteria under various environmental conditions. This article will hopefully stimulate further efforts to construct a comprehensive proteome database of bacterial OMVs that will help us not only to elucidate the biogenesis and functions of OMVs but also to develop diagnostic tools, vaccines, and antibiotics effective against pathogenic bacteria.

Anaerobic membrane bioreactors have potential for energy-efficient treatment of domestic and other wastewaters, membrane fouling being a major hurdle to application. It was found that fouling can be controlled if membranes are placed directly in contact with the granular activated carbon (GAC) in an anaerobic fluidized bed bioreactor (AFMBR) used here for post-treatment of effluent from another anaerobic reactor treating dilute wastewater. A 120-d continuous-feed evaluation was conducted using this two-stage anaerobic treatment system operated at 35 °C and fed a synthetic wastewater with chemical oxygen demand (COD) averaging 513 mg/L. The first-stage was a similar fluidized-bed bioreactor without membranes (AFBR), operated at 2.0-2.8 h hydraulic retention time (HRT), and was followed by the above AFMBR, operating at 2.2 h HRT. Successful membrane cleaning was practiced twice. After the second cleaning and membrane flux set at 10 L/m(2)/h, transmembrane pressure increased linearly from 0.075 to only 0.1 bar during the final 40 d of operation. COD removals were 88% and 87% in the respective reactors and 99% overall, with permeate COD of 7 ± 4 mg/L. Total energy required for fluidization for both reactors combined was 0.058 kWh/m(3), which could be satisfied by using only 30% of the gaseous methane energy produced. That of the AFMBR alone was 0.028 kWh/m(3), which is significantly less than reported for other submerged membrane bioreactors with gas sparging for fouling control.