The effects of elevated temperature and ocean acidity on bacterioplankton community structure and metabolism

By the end of the 21st century, mean sea surface temperatures are expected to increase 4°C, while atmospheric CO2 concentrations are predicted to triple causing seawater to become more acidic. These compounding effects will undoubtedly have major consequences for the organisms and processes in the oceans. Bacterioplankton play a vital role in the marine carbon cycle and the oceans\u27 ability to sequester CO2. We utilized pCO2 perturbation experiments to investigate the effects of elevated temperature and acidity on bacterioplankton community structure and metabolism. Terminalrestriction fragment length polymorphism (T-RFLP) revealed that bacterioplankton incubated in lower pH conditions exhibited a reduction of species richness, evenness, and overall diversity, relative to those incubated in ambient pH conditions. Non-metric multidimensional scaling (MDS) of T-RFLP data resulted in clustering by pH suggesting that pH influenced the structure of these communities. Shifts in the dominant members of bacterioplankton communities incubated under different pH were observed in both T-RFLP and clone library analyses. Both ambient and low pH communities were dominated by sequences of γ-proteobacteria and α-proteobacteria, although abundance of α-proteobacteria increased in communities incubated at lower pH. Although the representatives from these two classes were distinctly different between the treatments, a few taxa were found to be persistent in all treatments. Changes in the structure of bacterioplankton communities coincided with significant changes to their overall metabolism. Bacterial production rates decreased, while bacterial respiration increased under lower pH conditions. This study highlights the ability of bacterioplankton communities to respond to ocean acidification both structurally and metabolically, which may have significant implications for their ecological function in the marine carbon cycle and the ocean\u27s response to global climate change

MobiPADS: a reflective middleware for context-aware mobile computing

distributed computing services that essentially abstract the underlying network services to a monolithic “black box. ” In a mobile operating environment, the fundamental assumption of middleware abstracting a unified distributed service for all types of applications operating over a static network infrastructure is no longer valid. In particular, mobile applications are not able to leverage the benefits of adaptive computing to optimize its computation based on current contextual situations. In this paper, we introduce the Mobile Platform for Actively Deployable Service (MobiPADS) system. MobiPADS is designed to support context-aware processing by providing an executing platform to enable active service deployment and reconfiguration of the service composition in response to environments of varying contexts. Unlike most mobile middleware, MobiPADS supports dynamic adaptation at both the middleware and application layers to provide flexible configuration of resources to optimize the operations of mobile applications. Within the MobiPADS system, services (known as mobilets) are configured as chained service objects to provide augmented services to the underlying mobile applications so as to alleviate the adverse conditions of a wireless environment. Index Terms—Middleware, mobile applications, mobile computing support services, mobile environments.

The Effects of Ocean Acidity and Elevated Temperature on Bacterioplankton Community Structure and Metabolism

By the end of the 21st century, mean sea surface temperatures are expected to increase 4?C, while atmospheric CO2 concentrations are predicted to triple causing seawater to become acidic. These compounding effects will undoubtedly have major consequences for the organisms and processes in the oceans. Bacterioplankton play a vital role in the marine carbon cycle and the oceans’ ability to sequester CO2. We utilized pCO2 perturbation experiments to investigate the effects of ocean acidity and elevated temperature on bacterioplankton community structure and metabolism. Terminal-restriction fragment length polymorphism (T-RFLP) of small subunit ribosomal (SSU) genes revealed that bacterioplankton incubated in lower pH conditions exhibited a reduction of species richness, evenness, and overall diversity, relative to those incubated in ambient pH conditions. Non-metric multidimensional scaling (MDS) of T-RFLP data resulted in clustering by pH suggesting that pH influenced the structure of these communities. Shifts in the dominant members of bacterioplankton communities incubated under different pH were observed in both T-RFLP and SSU clone library analyses. Both ambient and low pH communities were dominated by Gammaproteobacteria and Alphaproteobacteria, although abundance of Alphaproteobacteria increased in communities incubated at lower pH. This was expressed by the gamma to alpha ratio dropping from ~9 to 4, respectively. In general, the representative taxa from these two classes were distinctly different between the treatments, with a few taxa found to be persistent in both treatments. Changes in the structure of bacterioplankton communities coincided with significant changes to their overall metabolism. Bacterial production rates decreased, while bacterial respiration increased under lower pH conditions. This study highlights the ability of bacterioplankton communities to respond to ocean acidification both structurally and metabolically, which may have significant implications for their ecological function in the marine carbon cycle and the ocean’s response to global climate change

Persistent hiccup in a continuous ambulatory peritoneal dialysis patient following ingestion of star fruit

AbstractAnimal studies have suggested that ingestion of star fruit, which belongs to the Oxalidaceae family, may cause neurotoxicity. Outbreaks of intractable hiccups have been reported following ingestion of star fruit in patients on regular hemodialysis. Other complaints have included insomnia, agitation and mental confusion. We report a patient on continuous ambulatory peritoneal dialysis (CAPD) who presented with acute confusion and persistent hiccup following ingestion of star fruit. Symptoms resolved spontaneously. Other reported cases and management strategies are discussed

mechanistic promiscuity in hydrogen atom abstraction reactions

In addition to oxometal [Mn+[double bond, length as m-dash]O] and imidometal [Mn+[double bond, length as m-dash]NR] units, transient metal–iodosylarene [M(n−2)+–O[double bond, length as m-dash]IPh] and metal–iminoiodane [M(n−2)+–N(R)[double bond, length as m-dash]IPh] adducts are often invoked as a possible “second oxidant” responsible for the oxo and imido group transfer reactivity. Although a few metal–iodosylarene adducts have been recently isolated and/or spectroscopically characterized, metal–iminoiodane adducts have remained elusive. Herein, we provide UV-Vis, EPR, NMR, XAS and DFT evidence supporting the formation of a metal–iminoiodane complex 2 and its scandium adduct 2-Sc. 2 and 2-Sc are reactive toward substrates in the hydrogen-atom and nitrene transfer reactions, which confirm their potential as active oxidants in metal-catalyzed oxidative transformations. Oxidation of para-substituted 2,6-di-tert-butylphenols by 2 and 2-Sc can occur by both coupled and uncoupled proton and electron transfer mechanisms; the exact mechanism depends on the nature of the para substituent

Brief advice and active referral for smoking cessation services among community smokers: a study protocol for randomized controlled trial

Abstract Background Most smokers do not use smoking cessation (SC) services although it increases successful quits. Passive referral providing SC information to smokers is commonly used in SC studies. Little was known about active referral in the community setting. This study aims to motivate community smokers to quit by brief SC advice using a validated AWARD model (Ask, Warn, Advise, Refer and Do-it-again) that adjunct with active referral of smokers to various SC services in Hong Kong. Methods/Design This is a single-blinded, parallel three-armed cluster randomized controlled trial (RCT) with two treatment groups of (1) brief SC advice using the AWARD model, active referral to SC services plus a referral card and a health warning leaflet (active referral group) and (2) brief SC advice using AWARD model and health warning leaflet (brief advice group) and a control group receives general very brief advice with a self-help booklet. A total of 1291 smokers will be recruited from 66 clusters (recruitment sessions) with 22 will be allocated to each of the two intervention and one control groups. SC ambassadors will be trained for delivering the interventions and conducting telephone follow-up. The primary outcomes are self-reported 7-days point prevalence (PP) abstinence at 3 and 6 months follow-up. Intention-to-treat principle and multi-level regressions will be used for data analysis. Discussion This is the first RCT on assessing a model combining brief advice and active referral to SC services among community smokers. The results will inform the practices of SC services and intervention studies. Trial registration NCT02539875 (ClinicalTrials.gov registry; registered retrospectively on 22 July 2015

Sport-specific balance ability in Taekwondo practitioners

ABSTRACT Fong SSM, Cheung CKY, Ip JY, Chiu JHN, Lam KLH, Tsang WWN. Sport-specific balance ability in Taekwondo practitioners. J. Hum. Sport Exerc. Vol. 7, No. 2, pp. 520-526, 2012. Taekwondo is a combat sport emphasizing on kicking techniques and dynamic footwork. Specialized balance ability is crucial for Taekwondo practitioners. This study aimed to compare (1) the postural stability during turning, and (2) the forward lunge distance between adolescent TKD practitioners and non-practitioners. Nineteen TKD practitioners (12 males, 7 females; Mean age ± SD: 15.58 ± 1.07 years) and nineteen control participants (13 males, 6 females; Mean age ± SD: 16.21 ± 0.98 years) were recruited in the study. Balance performance was assessed by the Forward Lunge Test and Step/Quick Turn Test with the NeuroCom Balance Master system. Forward lunge distance, turn time and turn sway were measured. TKD practitioners were found to turn faster by 35.37% (p=0.004) and sway less during turning by 15.23% (p=0.034) than non-practitioners. The forward lunge distance in TKD practitioners was 5.67% shorter than that in control participants (p=0.046). This study shows that TKD practitioners might have sport-specific balance ability. The findings of this study inspire the exploration of the longitudinal training effect of TKD so as to develop the evidence base for this exercise option to improve the postural control of adolescents with balance problems

Detecting the influence of initial pioneers on succession at deep-sea vents

© The Author(s), 2012. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in PLoS One 7 (2012): e50015, doi:10.1371/journal.pone.0050015.Deep-sea hydrothermal vents are subject to major disturbances that alter the physical and chemical environment and eradicate the resident faunal communities. Vent fields are isolated by uninhabitable deep seafloor, so recolonization via dispersal of planktonic larvae is critical for persistence of populations. We monitored colonization near 9°50′N on the East Pacific Rise following a catastrophic eruption in order to address questions of the relative contributions of pioneer colonists and environmental change to variation in species composition, and the role of pioneers at the disturbed site in altering community structure elsewhere in the region. Pioneer colonists included two gastropod species: Ctenopelta porifera, which was new to the vent field, and Lepetodrilus tevnianus, which had been rare before the eruption but persisted in high abundance afterward, delaying and possibly out-competing the ubiquitous pre-eruption congener L. elevatus. A decrease in abundance of C. porifera over time, and the arrival of later species, corresponded to a decrease in vent fluid flow and in the sulfide to temperature ratio. For some species these successional changes were likely due to habitat requirements, but other species persisted (L. tevnianus) or arrived (L. elevatus) in patterns unrelated to their habitat preferences. After two years, disturbed communities had started to resemble pre-eruption ones, but were lower in diversity. When compared to a prior (1991) eruption, the succession of foundation species (tubeworms and mussels) appeared to be delayed, even though habitat chemistry became similar to the pre-eruption state more quickly. Surprisingly, a nearby community that had not been disturbed by the eruption was invaded by the pioneers, possibly after they became established in the disturbed vents. These results indicate that the post-eruption arrival of species from remote locales had a strong and persistent effect on communities at both disturbed and undisturbed vents.The authors received funding from National Science Foundation grant OCE-0424953, WHOI Deep Ocean Exploration Institute, WHOI Summer Student Fellow program, Woods Hole Partnership in Education Program, IFREMER and CNRS, Fondation TOTAL Chair Extreme Marine Environment, Biodiversity and Global change