Granule formation mechanisms within an aerobic wastewater system for phosphorus removal

Granular sludge is a novel alternative for the treatment of wastewater and offers numerous operational and economic advantages over conventional floccular-sludge systems. The majority of research on granular sludge has focused on optimization of engineering aspects relating to reactor operation with little emphasis on the fundamental microbiology. In this study, we hypothesize two novel mechanisms for granule formation as observed in three laboratory scale sequencing batch reactors operating for biological phosphorus removal and treating two different types of wastewater. During the initial stages of granulation, two distinct granule types (white and yellow) were distinguished within the mixed microbial population. White granules appeared as compact, smooth, dense aggregates dominated by 97.5% "Candidatus Accumulibacter phosphatis," and yellow granules appeared as loose, rough, irregular aggregates with a mixed microbial population of 12.3% "Candidatus Accumulibacter phosphatis" and 57.9% "Candidatus Competibacter phosphatis," among other bacteria. Microscopy showed white granules as homogeneous microbial aggregates and yellow granules as segregated, microcolony-like aggregates, with phylogenetic analysis suggesting that the granule types are likely not a result of strain-associated differences. The microbial community composition and arrangement suggest different formation mechanisms occur for each granule type. White granules are hypothesized to form by outgrowth from a single microcolony into a granule dominated by one bacterial type, while yellow granules are hypothesized to form via multiple microcolony aggregation into a microcolony-segregated granule with a mixed microbial population. Further understanding and application of these mechanisms and the associated microbial ecology may provide conceptual information benefiting start-up procedures for full-scale granular-sludge reactors

Universal diffusion of dendrimers in a semidilute solution of linear polymers

The static and dynamic properties of dendrimers in semidilute solutions of linear chains of comparable size are investigated using Brownian dynamics simulations. The radius of gyration and diffusivity of a wide variety of low generation dendrimers and linear chains in solution follow universal scaling laws independent of their topology. Analysis of the shape functions and internal density of dendrimers shows that they are more spherical than linear chains and have a dense core. At intermediate times, dendrimers become subdiffusive, with an exponent higher than that previously reported for nanoparticles in semidilute polymer solutions. The long-time diffusivity of dendrimers does not follow theoretical predictions for nanoparticles. We propose a new scaling law for the long-time diffusion coefficient of dendrimers which accounts for the fact that, unlike nanoparticles, dendrimers shrink with an increase in background solution concentration. Analysis of the properties of a special case of a higher functionality dendrimer shows a transition from polymer-like to nanoparticle-like behaviour.Comment: 20 pages, 14 figures, includes supplementary informatio

The effect of ball carrying on the sprinting speed of international rugby union players

Speed is considered to be a highly valuable ability in rugby union. One unique aspect of rugby is that players need to be effective at sprinting while carrying a rugby ball. Previous research reported that amateur club players were slower while sprinting with the ball, than without. The purpose of the current research was to examine how sprinting while carrying a ball affected the sprinting speed of international rugby players. Twenty-six international players performed 6 x 40 m sprints under three conditions: Ball One Hand (B1H), Ball Two Hands (B2H) and No Ball (NB). Timing gates were placed at the 0 m, 10 m, 30 m and the 40m mark of the sprint. The 0-10m was used to examine initial acceleration; 30-40 m was used to examine maximal velocity and the 10-30 m section to analyze the acceleration up to maximal velocity. Comparisons were also made between backs and forwards. Backs were found to be faster than forwards at each of the splits for the NB, B1H and B2H conditions (0.04 - 0.08 s,

The gut virome and the relevance of temperate phages in human health

Alterations in the gut virome impact human health. Bacteriophages, viruses that infect bacteria, dominate the gut virome and are mainly composed by virulent and temperate phages. While virulent phages exclusively replicate within and lyse their bacterial host’s cell, temperate phages switch from an integrated state residing within their bacterial host’s chromosome to an induced free virion state via an induction event. How often do these induction events occur and what are their implications on gut homeostasis? Here, we summarize the current knowledge of the gut virome based on metagenomics and present how the proportion of induced temperate phages varies amongst individuals, age, and disease states. Finally, we highlight the importance of building upon classical culture-dependent techniques and sequencing approaches to improve our understanding of temperate phages to enable their potential therapeutic use

Late-Holocene floodplain development, land-use, and hydroclimate–flood relationships on the lower Ohio River, US

Floodplain development, land-use, and flooding on the lower Ohio River are investigated with a 3100-year-long sediment archive from Avery Lake, a swale lake on the Black Bottom floodplain in southern Illinois, US. In all, 12 radiocarbon dates show that Avery Lake formed at 1130 BCE (3100 cal. yr BP), almost 3000 years later than previously thought, indicating that the Black Bottom floodplain is younger and more dynamic than previously estimated. Three subsequent periods of extensive land clearance were identified by changes in pollen composition, corresponding to Native American occupations before 1500 CE and the current Euro-American occupation beginning in the 18th century. Sedimentation rates prior to 1820 CE changed independently of land clearance events, suggesting natural as opposed to land-use controls. Comparison with high-resolution paleoclimate data from Martin Lake, IN, indicates that lower Ohio River flooding was frequent when cold-season precipitation originating from the Pacific/Arctic predominated when atmospheric circulation resembled positive Pacific North American (PNA) conditions and the Pacific Decadal Oscillation (PDO) was in a positive mean state (1130 BCE to 350 CE and 1150–1820 CE). Conversely, Ohio River flooding was less frequent when warm-season precipitation from the Gulf of Mexico prevailed during negative PDO- and PNA-like mean states (350 and 1150 CE). This flood dynamic appears to have been fundamentally altered after 1820 CE. We suggest that extensive land clearance in the Ohio River watershed increased runoff and landscape erosion by reducing interception, infiltration, and evapotranspiration, thereby increasing flooding despite a shift to negative PDO- and PNA-like mean states. Predicted increases in average precipitation and extreme rainfall events across the mid-continental US are likely to perpetuate current trends toward more frequent flood events, because anthropogenic modifications have made the landscape less resilient to changing hydroclimatic conditions

Neighbourhood unemployment and other socio-demographic predictors of emergency hospitalisation for infectious intestinal disease in England: A longitudinal ecological study

BACKGROUND:Previous studies have observed that infectious intestinal disease (IID) related hospital admissions are higher in more deprived neighbourhoods. These studies have mainly focused on paediatric populations and are cross-sectional in nature. This study examines recent trends in emergency IID admission rates, and uses longitudinal methods to investigate the effects of unemployment (as a time varying measure of neighbourhood deprivation) and other socio-demographic characteristics on IID admissions for adults and children in England. METHODS:A longitudinal ecological analysis was performed using Hospital Episode Statistics on emergency hospitalisations for IID, collected over the time period 2012-17 across England. Analysis was conducted at the neighbourhood (Lower-layer Super Output Area) level for three age groups (0-14; 15-64; 65+ years). Mixed-effect Poisson regression models were used to assess the relationship between trends in neighbourhood unemployment and emergency IID admission rates, whilst controlling for measures of primary and secondary care access, underlying morbidity and the ethnic composition of each neighbourhood. RESULTS:From 2012-17, declining trends in emergency IID admission rates were observed for children and older adults overall, while rates increased for some sub-groups in the population. Each 1 percentage point increase in unemployment was associated with a 6.3, 2.4 and 4% increase in the rate of IID admissions per year for children [IRR=1.06, 95%CI 1.06-1.07], adults [IRR=1.02, 95%CI 1.02-1.03] and older adults [IRR=1.04, 95%CI 1.036-1.043], respectively. Increases in poor primary care access, the percentage of people from a Pakistani ethnic background, and the prevalence of long-term health problems, in a neighbourhood, were also associated with increases in IID admission rates. CONCLUSIONS:Increasing trends in neighbourhood deprivation, as measured by unemployment, were associated with increases in emergency IID admission rates for children and adults in England, despite controlling for measures of healthcare access, underlying morbidity and ethnicity. Research is needed to improve understanding of the mechanisms that explain these inequalities, so that effective policies can be developed to reduce the higher emergency IID admission rates experienced by more disadvantaged communities

The Virome of Cerebrospinal Fluid: Viruses Where We Once Thought There Were None.

Traditionally, medicine has held that some human body sites are sterile and that the introduction of microbes to these sites results in infections. This paradigm shifted significantly with the discovery of the human microbiome and acceptance of these commensal microbes living across the body. However, the central nervous system (CNS) is still believed by many to be sterile in healthy people. Using culture-independent methods, we examined the virome of cerebrospinal fluid (CSF) from a cohort of mostly healthy human subjects. We identified a community of DNA viruses, most of which were identified as bacteriophages. Compared to other human specimen types, CSF viromes were not ecologically distinct. There was a high alpha diversity cluster that included feces, saliva, and urine, and a low alpha diversity cluster that included CSF, body fluids, plasma, and breast milk. The high diversity cluster included specimens known to have many bacteria, while other specimens traditionally assumed to be sterile formed the low diversity cluster. There was an abundance of viruses shared among CSF, breast milk, plasma, and body fluids, while each generally shared less with urine, feces, and saliva. These shared viruses ranged across different virus families, indicating that similarities between these viromes represent more than just a single shared virus family. By identifying a virome in the CSF of mostly healthy individuals, it is now less likely that any human body site is devoid of microbes, which further highlights the need to decipher the role that viral communities may play in human health

60 million years of glaciation in the Transantarctic Mountains

The Antarctic continent reached its current polar location ~83 Ma and became shrouded by ice sheets ~34 Ma, coincident with dramatic global cooling at the Eocene-Oligocene boundary. However, it is not known whether the first Antarctic glaciers formed immediately prior to this or were present significantly earlier. Here we show that mountain glaciers were likely present in the Transantarctic Mountains during the Late Palaeocene (~60–56 Ma) and middle Eocene (~48–40 Ma). Temperate (warm-based) glaciers were prevalent during the Late Eocene (~40–34 Ma) and, in reduced numbers, during the Oligocene (~34–23 Ma), before larger, likely cold-based, ice masses (including ice sheets) dominated. Some temperate mountain glaciers were present during the Miocene Climatic Optimum (~15 Ma), before a widespread switch to cold-based glaciation. Our findings highlight the longevity of glaciation in Antarctica and suggest that glaciers were present even during the Early-Cenozoic greenhouse world

T. brucei cathepsin-L increases arrhythmogenic sarcoplasmic reticulum-mediated calcium release in rat cardiomyocytes

Aims: African trypanosomiasis, caused by Trypanosoma brucei species, leads to both neurological and cardiac dysfunction and can be fatal if untreated. While the neurological-related pathogenesis is well studied, the cardiac pathogenesis remains unknown. The current study exposed isolated ventricular cardiomyocytes and adult rat hearts to T. brucei to test whether trypanosomes can alter cardiac function independent of a systemic inflammatory/immune response. Methods and results: Using confocal imaging, T. brucei and T. brucei culture media (supernatant) caused an increased frequency of arrhythmogenic spontaneous diastolic sarcoplasmic reticulum (SR)-mediated Ca2+ release (Ca2+ waves) in isolated adult rat ventricular cardiomyocytes. Studies utilising inhibitors, recombinant protein and RNAi all demonstrated that this altered SR function was due to T. brucei cathepsin-L (TbCatL). Separate experiments revealed that TbCatL induced a 10–15% increase of SERCA activity but reduced SR Ca2+ content, suggesting a concomitant increased SR-mediated Ca2+ leak. This conclusion was supported by data demonstrating that TbCatL increased Ca2+ wave frequency. These effects were abolished by autocamtide-2-related inhibitory peptide, highlighting a role for CaMKII in the TbCatL action on SR function. Isolated Langendorff perfused whole heart experiments confirmed that supernatant caused an increased number of arrhythmic events. Conclusion: These data demonstrate for the first time that African trypanosomes alter cardiac function independent of a systemic immune response, via a mechanism involving extracellular cathepsin-L-mediated changes in SR function

Early life stress and macaque annygdala hypertrophy: preliminary evidence for a role for the serotonin transporter gene

Background: Children exposed to early life stress (ELS) exhibit enlarged amygdala volume in comparison to controls. the primary goal of this study was to examine amygdala volumes in bonnet macaques subjected to maternal variable foraging demand (VFD) rearing, a well-established model of ELS. Preliminary analyses examined the interaction of ELS and the serotonin transporter gene on amygdala volume. Secondary analyses were conducted to examine the association between amygdala volume and other stress-related variables previously found to distinguish VFD and non-VFD reared animals.Methods: Twelve VFD-reared and nine normally reared monkeys completed MRI scans on a 3T system (mean age = 5.2 years).Results: Left amygdala volume was larger in VFD vs. control macaques. Larger amygdala volume was associated with: high cerebrospinal fluid concentrations of corticotropin releasing-factor (CRF) determined when the animals were in adolescence (mean age = 2.7 years); reduced fractional anisotropy (FA) of the anterior limb of the internal capsule (ALIC) during young adulthood (mean age = 5.2 years) and timid anxiety-like responses to an intruder during full adulthood (mean age = 8.4 years). Right amygdala volume varied inversely with left hippocampal neurogenesis assessed in late adulthood (mean age = 8.7 years). Exploratory analyses also showed a gene-by-environment effect, with VFD-reared macaques with a single short allele of the serotonin transporter gene exhibiting larger amygdala volume compared to VFD-reared subjects with only the long allele and normally reared controls.Conclusion: These data suggest that the left amygdala exhibits hypertrophy after ELS, particularly in association with the serotonin transporter gene, and that amygdala volume variation occurs in concert with other key stress-related behavioral and neurobiological parameters observed across the lifecycle. Future research is required to understand the mechanisms underlying these diverse and persistent changes associated with ELS and amygdala volume.National Institute for Mental HealthNIMHNARSAD Mid-investigator AwardSuny Downstate Med Ctr, Dept Psychiat & Behav Sci, Brooklyn, NY 11203 USAUniversidade Federal de São Paulo, Dept Psiquiatria, São Paulo, BrazilMt Sinai Sch Med, Dept Psychiat, New York, NY USAMt Sinai Sch Med, Dept Neurosci, New York, NY USAMt Sinai Sch Med, Dept Radiol, New York, NY USANew York State Psychiat Inst & Hosp, New York, NY 10032 USAMichael E Debakey VA Med Ctr, Mental Hlth Care Line, Houston, TX USABaylor Coll Med, Menninger Dept Psychiat & Behav Sci, Houston, TX 77030 USAYale Univ, Sch Med, Dept Psychiat, New Haven, CT USANatl Ctr PTSD, Clin Neurosci Div, West Haven, CT USANew York State Psychiat Inst & Hosp, Dept Mol Imaging & Neuropathol, New York, NY 10032 USAColumbia Univ, Coll Phys & Surg, Dept Psychiat, New York, NY USAColumbia Univ, Coll Phys & Surg, Dept Pathol & Cell Biol, New York, NY USAComprehensive NeuroSci Corp, Westchester, NY USAUniv Miami Hlth Sytems, Dept Psychiat & Behav Sci, Miami, FL USAEmory Univ, Sch Med, Dept Psychiat & Behav Sci, Emory, GA USAUniversidade Federal de São Paulo, Dept Psiquiatria, São Paulo, BrazilNational Institute for Mental Health: R01MH65519-01National Institute for Mental Health: R01MH098073NIMH: R21MH066748NIMH: R01MH59990AWeb of Scienc