3,307 research outputs found

    The Fate of Sulfamethazine in Sodium-Hypochlorite-Treated Drinking Water: Monitoring by LC-MSN-IT-TOF

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    Pharmaceutical compounds represent a rapidly emerging class of environmental contaminants. Such compounds were recently classified by the U.S. Geological Survey, including several antibiotics. An LC-MS/MS screening method for the top five antibiotics in drinking water was developed and validated using a Shimadzu LC-MS-IT-TOF. The separation was performed using a Waters Acquity UPLC BEH C18 column with a gradient elution. Sulfamethazine was exposed to conditions intended to mimic drinking water chlorination, and samples were collected and quenched with excess sodium sulfite. Kinetics of sulfamethazine degradation was followed as well as the formation of the major chlorinated byproduct (m/z 313). For the screening method, all five antibiotic peaks were baseline resolved within 5 minutes. Additionally, precision and accuracy of the screening method were less than 15%. Degradation of sulfamethazine upon exposure to drinking water chlorination occurred by first order kinetics with a half-life of 5.3 × 10(4) min (approximately 37 days) with measurements starting 5 minutes after chlorination. Likewise, the formation of the major chlorinated product occurred by first order kinetics with a rate constant of 2.0 × 10(-2). The proposed identification of the chlorinated product was 4-amino-(5-chloro-4,6-dimethyl-2-pyrimidinyl)-benzenesulfonamide (C12H13N4O2SCl) using MS (n) spectra and databases searches of SciFinder and ChemSpider

    Speed and Terrain Impact Ground Reaction Forces During Load Carriage

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    Load carriage leads to larger, faster vertical ground reaction forces (GRFs), and greater risk of musculoskeletal injury. Although increased lower limb flexion can help dissipate the vertical GRF, reducing injury risk, it is unclear if terrain affects limb flexion and vertical GRFs during load carriage. This study quantified lower limb biomechanics as participants walked, jogged and ran with heavy body borne load over different terrain. We hypothesize that participants will decrease lower limb flexion, but increase peak vertical GRFs as speed increases, but these changes will vary with terrain. Each participant walked (1.3 m/s), jogged (3.0 m/s) and ran (4.5 m/s) with body borne load (15 kg) over a rocky, firm, soft, and flat terrain. During each locomotor task, peak vertical GRF and range of hip, knee and ankle motion (ROM) were calculated, and submitted to statistical analysis. Significant speed by surface interactions were evident for peak vertical GRF (p \u3c 0.001), and ankle and knee ROM (p=0.030 and p \u3c 0.001). Speed impacted peak vertical GRF, and ankle and knee ROM (all: p \u3c 0.001), where GRF and ankle were larger, but knee motion smaller during the run. Surface impacted peak vertical GRF and ankle ROM (p \u3c 0.001 and p=0.008). Unexpectedly, participants decreased peak vertical GRF on the rocky compared to all other surfaces. Through the use of this study, training programs can be adapted to help athletes and military personnel decrease their risk of injury while training

    Functional Compartmentalization of Endosomal Trafficking for the Synaptic Delivery of AMPA Receptors during Long-Term Potentiation

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    Endosomal membrane trafficking in dendritic spines is important for proper synaptic function and plasticity. However, little is known about the molecular identity and functional compartmentalization of the membrane trafficking machinery operating at the postsynaptic terminal. Here we report that the transport of AMPA-type glutamate receptors into synapses occurs in two discrete steps, and we identify the specific endosomal functions that control this process during long-term potentiation. We found that Rab11-dependent endosomes translocate AMPA receptors from the dendritic shaft into spines. Subsequently, an additional endosomal trafficking step, controlled by Rab8, drives receptor insertion into the synaptic membrane. Separate from this receptor delivery route, we show that Rab4 mediates a constitutive endosomal recycling within the spine. This Rab4-dependent cycling is critical for maintaining spine size but does not influence receptor transport. Therefore, our data reveal a highly compartmentalized endosomal network within the spine and identify the molecular components and functional organization of the membrane organelles that mediate AMPA receptor synaptic delivery during plasticity.This work was supported by National Institute of Mental Health Grants MH070417 (J.A.E.) and F31-MH070205 (T.C.B.). We thank Ronald Holz, Jeffrey Martens, Maria Soengas, and members of the Esteban laboratory for critical reading of this manuscript.Peer reviewe

    Sex and Limb Impact Biomechanics Associated with Risk of Injury During Drop Landing with Body Borne Load

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    Increasing lower limb flexion may reduce risk of musculoskeletal injury for military personnel during landing. This study compared lower limb biomechanics between sexes and limbs when using normal and greater lower limb flexion to land with body borne load. Thirty-three participants (21 male, 12 female, age: 21.6±2.5 years, height: 1.7±0.1 m, weight: 74.5±9.0 kg) performed normal and flexed lower limb landings with four body borne loads: 20, 25, 30 and 35 kg. Hip and knee biomechanics, peak vertical ground reaction force (GRF), and the magnitude and direction of the GRF vector in frontal plane were submitted to two separate repeated measures ANOVAs to test the main and interaction effects of sex, load, and landing, as well as limb, load, and landing. Participants increased GRFs (between 5 and 10%) and hip and knee flexion moments when landing with body borne load, but decreased vertical GRF 19% and hip adduction and knee abduction joint range of motion and moments during the flexed landings. Both females and the non-dominant limb presented greater risk of musculoskeletal injury during landing. Females exhibited larger GRFs, increased hip adduction range of motion, and greater knee abduction moments compared to males. Whereas, the non-dominant limb increased knee abduction moments and exhibited a more laterally-directed frontal plane GRF vector compared to the dominant limb during the loaded landings. Yet, increasing lower limb flexion during landing does not appear to produce similar reductions in lower limb biomechanics related to injury risk for both females and the non-dominant limb during landing

    Sex Impacts Leg Stiffness When Increasing Stride Length to Run with Body Borne Load

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    Military personnel routinely run at a fixed cadence with body borne load, which may increase leg stiffness and potential injury risk - particularly for females. Seventeen males and ten females had leg stiffness quantified when running with four loads (20, 25, 30, and 35 kg) and three stride lengths (preferred, and ±15% of preferred). Participants increased leg stiffness (P=0.006), and potentially injury risk when running with load. But, a sex dimorphism in stiffness was evident with changes in stride length. Males exhibited reduced leg stiffness with longer strides (P\u3e0.05)

    IRF3 polymorphisms induce different innate anti-Theiler's virus immune responses in RAW264.7 macrophages

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    AbstractPersistent viral infections can lead to disease such as myocarditis. Theiler's murine encephalomyelitis virus (TMEV) infects macrophages of SJL/J (H-2s) mice establishing persistent infections leading to demyelinating disease. In contrast macrophages from B10.S (H-2s) mice clear TMEV. Activation of the transcription factor IRF3 induces IFNβ, ISG56, and apoptosis for viral clearance, but also inflammatory cytokines, such as IL-23 and IL6, which contribute to disease. Here we identify polymorphisms in the IRF3 of SJL/J versus B10.S mice that are located in DNA binding, nuclear localization, and autoinhibitory domains. SJL-IRF3 expression in RAW264.7 macrophage cells with or without TMEV infection decreased IL-23p19 promoter activity compared with B10S-IRF3. In contrast SJL-IRF3 increased IL-6, ISG56 and IFNβ in response to TMEV. B10S-IRF3 expression augmented apoptotic caspase activation and decreased viral RNA in TMEV-infected macrophages while SJL-IRF3 increased viral replication with less caspase activation. Therefore IRF3 polymorphisms contribute to viral persistence and altered cytokine expression

    Assessing population impacts of toxicant-induced disruption of breeding behaviours using an individual-based model for the three-spined stickleback

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     This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this recordThe effects of toxicant exposure on individuals captured in standard environmental risk assessments (ERA) do not necessarily translate proportionally into effects at the population-level. Population models can incorporate population resilience, physiological susceptibility, and likelihood of exposure, and can therefore be employed to extrapolate from individual- to population-level effects in ERA. Here, we present the development of an individual-based model (IBM) for the three-spined stickleback (Gasterosteus aculeatus) and its application in assessing population-level effects of disrupted male breeding behaviour after exposure to the anti-androgenic pesticide, fenitrothion. The stickleback is abundant in marine, brackish, and freshwater systems throughout Europe and their complex breeding strategy makes wild populations potentially vulnerable to the effects of endocrine disrupting chemicals (EDCs). Modelled population dynamics matched those of a UK field population and the IBM is therefore considered to be representative of a natural population. Literature derived dose-response relationships of fenitrothion-induced disruption of male breeding behaviours were applied in the IBM to assess population-level impacts. The modelled population was exposed to fenitrothion under both continuous (worst-case) and intermittent (realistic) exposure patterns and population recovery was assessed. The results suggest that disruption of male breeding behaviours at the individual-level cause impacts on population abundance under both fenitrothion exposure regimes; however, density-dependent processes can compensate for some of these effects, particularly for an intermittent exposure scenario. Our findings further demonstrate the importance of understanding life-history traits, including reproductive strategies and behaviours, and their density-dependence, when assessing the potential population-level risks of EDCs.Syngenta LtdBiotechnology and Biological Sciences Research Council (BBSRC

    Assessing risks and mitigating impacts of harmful algal blooms on mariculture and marine fisheries

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    Aquaculture is the fastest growing food sector globally and protein provisioning from aquaculture now exceeds that from wild capture fisheries. There is clear potential for the further expansion of marine aquaculture (mariculture), but there are associated risks. Some naturally occurring algae can proliferate under certain environmental conditions, causing deoxygenation of seawater, or releasing toxic compounds (phycotoxins), which can harm wild and cultured finfish and shellfish, and also human consumers. The impacts of these so‐called harmful algal blooms (HABs) amount to approximately 8 $billion/yr globally, due to mass mortalities in finfish, harvesting bans preventing the sale of shellfish that have accumulated unsafe levels of HAB phycotoxins and unavoided human health costs. Here, we provide a critical review and analysis of HAB impacts on mariculture (and wild capture fisheries) and recommend research to identify ways to minimise their impacts to the industry. We examine causal factors for HAB development in inshore versus offshore locations and consider how mariculture itself, in its various forms, may exacerbate or mitigate HAB risk. From a management perspective, there is considerable scope for strategic siting of offshore mariculture and holistic Environmental Approaches for Aquaculture, such as offsetting nutrient outputs from finfish farming, via the co‐location of extractive shellfish and macroalgae. Such pre‐emptive, ecosystem‐based approaches are preferable to reactive physical, chemical or microbiological control measures aiming to remove or neutralise HABs and their phycotxins. To facilitate mariculture expansion and long‐term sustainability, it is also essential to evaluate HAB risk in conjunction with climate change

    Sex Impact on Knee and Ankle Muscle Extensor Forces During Loaded Running

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    Background: This study determined whether the knee and ankle muscle extensor forces increase when running with a body-borne load and whether these forces differ between the sexes. Methods: Thirty-six (twenty male and sixteen female) adults had the knee and ankle extensor force quantified when running 4.0 m/s with four body-borne loads (20, 25, 30, and 35 kg). Peak normalized (BW) and unnormalized (N) extensor muscle force, relative effort, and joint angle and angular velocity at peak muscle force for both the ankle and the knee were submitted to a mixed model ANOVA. Results: Significant load by sex interactions for knee unnormalized extensor force (p = 0.025) and relative effort (p = 0.040) were observed, as males exhibited greater knee muscle force and effort than females and increased their muscle force and effort with additional load. Males also exhibited greater ankle normalized and unnormalized extensor force (p = 0.004, p \u3c 0.001) and knee unnormalized force than females (p = 0.005). The load increased the normalized ankle and knee muscle force (p \u3c 0.001, p = 0.030) and relative effort (p \u3c 0.001, p = 0.044) and the unnormalized knee muscle force (p = 0.009). Conclusion: Running with a load requires greater knee and ankle extensor force, but males exhibited greater increases in muscle force, particularly at the knee, than females

    Factors Determining the Susceptibility of Fish to Effects of Human Pharmaceuticals

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    This is the final version. Available on open access from the American Chemical Society via the DOI in this recordThe increasing levels and frequencies at which active pharmaceutical ingredients (APIs) are being detected in the environment are of significant concern, especially considering the potential adverse effects they may have on nontarget species such as fish. With many pharmaceuticals lacking environmental risk assessments, there is a need to better define and understand the potential risks that APIs and their biotransformation products pose to fish, while still minimizing the use of experimental animals. There are both extrinsic (environment- and drug-related) and intrinsic (fish-related) factors that make fish potentially vulnerable to the effects of human drugs, but which are not necessarily captured in nonfish tests. This critical review explores these factors, particularly focusing on the distinctive physiological processes in fish that underlie drug absorption, distribution, metabolism, excretion and toxicity (ADMET). Focal points include the impact of fish life stage and species on drug absorption (A) via multiple routes; the potential implications of fish’s unique blood pH and plasma composition on the distribution (D) of drug molecules throughout the body; how fish’s endothermic nature and the varied expression and activity of drug-metabolizing enzymes in their tissues may affect drug metabolism (M); and how their distinctive physiologies may impact the relative contribution of different excretory organs to the excretion (E) of APIs and metabolites. These discussions give insight into where existing data on drug properties, pharmacokinetics and pharmacodynamics from mammalian and clinical studies may or may not help to inform on environmental risks of APIs in fish.ServierEuropean Union Horizon 2020European Federation of Pharmaceutical Industries and Association
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