Per- and polyfluoroalkyl substances (PFAS), trace elements and life history parameters of mass-stranded common dolphins (Delphinus delphis) in New Zealand.

Profiles of 33 PFAS analytes and 12 essential and non-essential trace elements were measured in livers of stranded common dolphins (Delphinus delphis) from New Zealand. PFAS concentrations reported were largely comparable to those measured in other marine mammal species globally and composed mostly of long-chain compounds including perfluorooctanesulfonic acid (PFOS), perfluorododecanoic acid (PFDoDA), perfluorotridecanoic acid (PFTrDA) and perfluorooctanesulfonamide (FOSA). PFAS profiles did not vary significantly by location, body condition, or life history. Notably, significant positive correlations were observed within respective PFAS and trace elements. However, only negative correlations were evident between these two contaminant types, suggesting different exposure and metabolic pathways. Age-associated concentrations were found for PFTrDA and four trace elements, i.e. silver, mercury, cadmium, selenium, indicating differences in the bioaccumulation biomagnification mechanisms. Overall, our results contribute to global understanding of accumulation of PFAS by offering first insights of PFAS exposure in cetaceans living within South Pacific Australasian waters.

The implications of lag times between nitrate leaching losses and riverine loads for water quality policy.

Understanding the lag time between land management and impacts on riverine nitrate-nitrogen (N) loads is critical to understand when action to mitigate nitrate-N leaching losses from the soil profile may start improving water quality. These lags occur due to leaching of nitrate-N through the subsurface (soil and groundwater). Actions to mitigate nitrate-N losses have been mandated in New Zealand policy to start showing improvements in water quality within five years. We estimated annual rates of nitrate-N leaching and annual nitrate-N loads for 77 river catchments from 1990 to 2018. Lag times between these losses and riverine loads were determined for 34 catchments but could not be determined in other catchments because they exhibited little change in nitrate-N leaching losses or loads. Lag times varied from 1 to 12 years according to factors like catchment size (Strahler stream order and altitude) and slope. For eight catchments where additional isotope and modelling data were available, the mean transit time for surface water at baseflow to pass through the catchment was on average 2.1 years less than, and never greater than, the mean lag time for nitrate-N, inferring our lag time estimates were robust. The median lag time for nitrate-N across the 34 catchments was 4.5 years, meaning that nearly half of these catchments wouldn't exhibit decreases in nitrate-N because of practice change within the five years outlined in policy.

Comprehensive Analysis of Adverse Events Associated with Gastric Peroral Endoscopic Myotomy: An International Multicenter Study.

BACKGROUND: Gastric peroral endoscopic myotomy (G-POEM) has emerged as an effective management approach for patients with refractory gastroparesis. This study aims to comprehensively study the safety of G-POEM and describe the predictive factors of adverse events (AEs) occurrence. METHODS: This study is a retrospective study involving 13 tertiary care centers (7 USA, 1 South America, 4 Europe, and 1 Asia). Patients who underwent G-POEM for refractory gastroparesis were included. Cases were identified by the occurrence of AEs. For each case, two controls were randomly selected and matched for age (± 10 years), gender, and etiology of gastroparesis. RESULTS: A total of 216 patients underwent G-POEM for gastroparesis. Overall, 31 (14%) AEs were encountered [mild 24 (77%), moderate 5 (16%), and severe 2 (6%)] during the duration of the study. The most common AE was abdominal pain (n = 16), followed by mucosotomy (n = 5) and capnoperitoneum (n = 4), and AEs were most commonly identified within the first 48-h post-procedure 18 (58%). The risk of adverse event occurrence was significantly higher for endoscopists with experience of < 20 G-POEM procedures (OR 3.03 [1.03-8.94], p < 0.05). CONCLUSION: G-POEM seems to be a safe intervention for refractory gastroparesis. AEs are most commonly mild and managed conservatively. Longitudinal mucosal incision, use of hook knife, use of clips for mucosal closure and endoscopist's experience with > 20 G-POEM procedures is significantly associated with decreased incidence of AEs.

The effect of the visual exercise environment on the response to psychological stress: a pilot study.

Background: Performing physical activity whilst exposed to nature can improve health. However, there is little evidence of its impact on stress outcomes. The aim of this study was to examine the influence of the visual exercise environment on the response to a psychosocial stressor. Methods: Eighteen participants were randomized to one of three conditions: i. nature; ii. built or; iii. control condition. Participants exercised for 30 min on a treadmill at 50% of their VO2max whilst viewing a video of either a natural or built environment or a blank screen. Following the exercise, participants completed the Trier Social Stress Test (TSST), a standardized laboratory stressor. Salivary samples were collected before, during and after the TSST to calculate cortisol reactivity and recovery. Results: One-way ANOVA revealed a significant effect of viewing condition on cortisol reactivity [F(2, 11) = 4.686, p = .034; n2p = .460]; with significantly lower reactivity in the built compared to the nature condition (p = .027, d = 1.73). There was no effect of condition on cortisol recovery (p = .137; n2p = .257). Conclusions: In the context of the adverse health impact of lower (i.e., blunted) cortisol responding, these findings could indicate a negative impact of the built environment on stress responses.

Below the surface: Twenty-five years of seafloor litter monitoring in coastal seas of North West Europe (1992-2017).

Marine litter presents a global problem, with increasing quantities documented in recent decades. The distribution and abundance of marine litter on the seafloor off the United Kingdom's (UK) coasts were quantified during 39 independent scientific surveys conducted between 1992 and 2017. Widespread distribution of litter items, especially plastics, were found on the seabed of the North Sea, English Channel, Celtic Sea and Irish Sea. High variation in abundance of litter items, ranging from 0 to 1835 pieces km-2 of seafloor, was observed. Plastic tems such as bags, bottles and fishing related debris were commonly observed across all areas. Over the entire 25-year period (1992-2017), 63% of the 2461 trawls contained at least one plastic litter item. There was no significant temporal trend in the percentage of trawls containing any or total plastic litter items across the long-term datasets. Statistically significant trends, however, were observed in specific plastic litter categories only. These trends were all positive except for a negative trend in plastic bags in the Greater North Sea - suggesting that behavioural and legislative changes could reduce the problem of marine litter within decades.

Private well groundwater quality in West Virginia, USA-2010.

The Centers for Disease Control and Prevention (CDC), in collaboration with the West Virginia Bureau of Public Health (BPH), initiated an investigation to characterize private well water quality in West Virginia. The objective was to better characterize private well water across various aquifer geologies by testing household drinking water samples and comparing them to EPA's National Primary Drinking Water Standards. The BPH selected ten counties representing three regions to capture geologically diverse areas that represent varying aquifer geology. We collected well-water samples from participating households and analyzed all water samples for 20 constituents currently monitored in public drinking-water systems. We calculated geometric means for each constituent and compared metal concentrations to EPA maximum and secondary contaminant levels by the geologic age of the rock surrounding the aquifer where the sample was obtained. All participating households (n=139) provided a water sample. We detected arsenic at levels higher than the EPA maximum contaminant level in 10 (7.2%) samples. We detected elevated radon-222 in 48 (34.5%) samples. Geologic age of the region was indicative of whether arsenic and radon-222 were present at levels that exceeded current EPA drinking water standards. We found arsenic and radon concentrations were higher in Permian aquifers compared to those of other geologic ages. Homeowners with private wells in areas with Permian aged aquifers could benefit from targeted public health messaging about potentially harmful constituent concentrations in the well water. This may help ensure proper testing and maintenance of private wells and reduce exposure to these constituents.

Studying the effects of asymmetry on the bending rigidity of lipid membranes formed by microfluidics.

In this article we detail a robust high-throughput microfluidic platform capable of fabricating either symmetric or asymmetric giant unilamellar vesicles (GUVs) and characterise the mechanical properties of their membranes.

Top-down assessment of the Asian carbon budget since the mid 1990s.

Increasing atmospheric carbon dioxide (CO2) is the principal driver of anthropogenic climate change. Asia is an important region for the global carbon budget, with 4 of the world's 10 largest national emitters of CO2. Using an ensemble of seven atmospheric inverse systems, we estimated land biosphere fluxes (natural, land-use change and fires) based on atmospheric observations of CO2 concentration. The Asian land biosphere was a net sink of -0.46 (-0.70-0.24) PgC per year (median and range) for 1996-2012 and was mostly located in East Asia, while in South and Southeast Asia the land biosphere was close to carbon neutral. In East Asia, the annual CO2 sink increased between 1996-2001 and 2008-2012 by 0.56 (0.30-0.81) PgC, accounting for ∼35% of the increase in the global land biosphere sink. Uncertainty in the fossil fuel emissions contributes significantly (32%) to the uncertainty in land biosphere sink change.

Effect of concentrate feeding method on the performance of dairy cows in early to mid lactation.

The objective of the current study was to determine the effects of concentrate feeding method on milk yield and composition, dry matter (DM) intake (DMI), body weight and body condition score, reproductive performance, energy balance, and blood metabolites of housed (i.e., accommodated indoors) dairy cows in early to mid lactation. Eighty-eight multiparous Holstein-Friesian cows were managed on 1 of 4 concentrate feeding methods (CFM; 22 cows per CFM) for the first 21 wk postpartum. Cows on all 4 CFM were offered grass silage plus maize silage (in a 70:30 ratio on a DM basis) ad libitum throughout the study. In addition, cows had a target concentrate allocation of 11 kg/cow per day (from d 13 postpartum) via 1 of 4 CFM, consisting of (1) offered on a flat-rate basis via an out-of-parlor feeding system, (2) offered based on individual cow's milk yields in early lactation via an out-of-parlor feeding system, (3) offered as part of a partial mixed ration (target intake of 5 kg/cow per day) with additional concentrate offered based on individual cow's milk yields in early lactation via an out-of-parlor feeding system, and (4) offered as part of a partial mixed ration containing a fixed quantity of concentrate for each cow in the group. In addition, all cows were offered 1 kg/cow per day of concentrate pellets via an in-parlor feeding system. We detected no effect of CFM on concentrate or total DMI, mean daily milk yield, concentrations and yields of milk fat and protein, or metabolizable energy intakes, requirements, or balances throughout the study. We also found no effects of CFM on mean or final body weight, mean or final body condition score, conception rates to first service, or any of the blood metabolites examined. The results of this study suggest that CFM has little effect on the overall performance of higher-yielding dairy cows in early to mid lactation when offered diets based on conserved forages.

The effect of hydrostatic pressure on model membrane domain composition and lateral compressibility.

Phase separation in ternary model membranes is known to occur over a range of temperatures and compositions and can be induced by increasing hydrostatic pressure. We have used small angle X-ray scattering (SAXS) to study phase separation along pre-determined tie lines in dioleoylphosphatidylcholine (DOPC), dipalmitoylphosphatidylcholine (DPPC) and cholesterol (CHOL) mixtures. We can unequivocally distinguish the liquid ordered (Lo) and liquid disordered (Ld) phases in diffraction patterns from biphasic mixtures and compare their lateral compressibility. The variation of tie line endpoints with increasing hydrostatic pressure was determined, at atmospheric pressure and up to 100 MPa. We find an extension and shift of the tie lines towards the DOPC rich region of the phase diagram at increased pressure, this behaviour differs slightly from that reported for decreasing temperature.

Baseline survey of marine sediments collected from the State of Kuwait: PAHs, PCBs, brominated flame retardants and metal contamination.

A geographically extensive baseline survey of sediment contamination was undertaken at twenty nine locations around Kuwait. Samples were assessed in relation to a wide range of industrial pollutants, including metals, PAHs, PCBs, PBDEs and HBCDs. The data generated indicated that levels of pollutants were generally low and below commonly applied sediment quality guidelines (SQGs). However, naturally high background concentrations of certain metals present in sediment from the region may prohibit the direct assessment against some of the routinely applied SQGs. Hot spots of contamination were identified for PAHs, PCBs and PBDEs, that were mainly associated with the Shuaiba Industrial Area, located south of the city, and known to contain a diverse mix of both light and heavy industry.

Evaluation of water displacement energetics in protein binding sites with grid cell theory.

Excess free energies, enthalpies and entropies of water in protein binding sites were computed via classical simulations and Grid Cell Theory (GCT) analyses for three pairs of congeneric ligands in complex with the proteins scytalone dehydratase, p38α MAP kinase and EGFR kinase respectively. Comparative analysis is of interest since the binding modes for each ligand pair differ in the displacement of one binding site water molecule, but significant variations in relative binding affinities are observed. Protocols that vary in their use of restraints on protein and ligand atoms were compared to determine the influence of protein-ligand flexibility on computed water structure and energetics, and to assess protocols for routine analyses of protein-ligand complexes. The GCT-derived binding affinities correctly reproduce experimental trends, but the magnitude of the predicted changes in binding affinities is exaggerated with respect to results from a previous Monte Carlo Free Energy Perturbation study. Breakdown of the GCT water free energies into enthalpic and entropic components indicates that enthalpy changes dominate the observed variations in energetics. In EGFR kinase GCT analyses revealed that replacement of a pyrimidine by a cyanopyridine perturbs water energetics up three hydration shells away from the ligand.

Temperature and pressure tuneable swollen bicontinuous cubic phases approaching nature's length scales.

Bicontinuous cubic structures offer enormous potential in applications ranging from protein crystallisation to drug delivery systems and have been observed in cellular membrane structures. One of the current bottlenecks in understanding and exploiting these structures is that cubic scaffolds produced in vitro are considerably smaller in size than those observed in biological systems, differing by almost an order of magnitude in some cases. We have addressed this technological bottleneck and developed a methodology capable of manufacturing highly swollen bicontinuous cubic membranes with length scales approaching those seen in vivo. Crucially, these cubic systems do not require the presence of proteins. We have generated highly swollen Im3m symmetry bicontinuous cubic phases with lattice parameters of up to 480 Å, composed of ternary mixtures of monoolein, cholesterol and negatively charged lipid (DOPS or DOPG) and we have been able to tune their lattice parameters. The swollen cubic phases are highly sensitive to both temperature and pressure; these structural changes are likely to be controlled by a fine balance between lipid headgroup repulsions and lateral pressure in the hydrocarbon chain region.

A microfluidic platform for size-dependent generation of droplet interface bilayer networks on rails.

Droplet interface bilayer (DIB) networks are emerging as a cornerstone technology for the bottom up construction of cell-like and tissue-like structures and bio-devices. They are an exciting and versatile model-membrane platform, seeing increasing use in the disciplines of synthetic biology, chemical biology, and membrane biophysics. DIBs are formed when lipid-coated water-in-oil droplets are brought together-oil is excluded from the interface, resulting in a bilayer. Perhaps the greatest feature of the DIB platform is the ability to generate bilayer networks by connecting multiple droplets together, which can in turn be used in applications ranging from tissue mimics, multicellular models, and bio-devices. For such applications, the construction and release of DIB networks of defined size and composition on-demand is crucial. We have developed a droplet-based microfluidic method for the generation of different sized DIB networks (300-1500 pl droplets) on-chip. We do this by employing a droplet-on-rails strategy where droplets are guided down designated paths of a chip with the aid of microfabricated grooves or "rails," and droplets of set sizes are selectively directed to specific rails using auxiliary flows. In this way we can uniquely produce parallel bilayer networks of defined sizes. By trapping several droplets in a rail, extended DIB networks containing up to 20 sequential bilayers could be constructed. The trapped DIB arrays can be composed of different lipid types and can be released on-demand and regenerated within seconds. We show that chemical signals can be propagated across the bio-network by transplanting enzymatic reaction cascades for inter-droplet communication.

Preparation and mechanical characterisation of giant unilamellar vesicles by a microfluidic method.

Giant unilamellar vesicles (GUVs) have a wide range of applications in biology and synthetic biology. As a result, new approaches for constructing GUVs using microfluidic techniques are emerging but there are still significant shortcomings in the control of fundamental vesicle structural parameters such as size, lamellarity, membrane composition and internal contents. We have developed a novel microfluidic platform to generate compositionally-controlled GUVs. Water-in-oil (W/O) droplets formed in a lipid-containing oil flow are transferred across an oil-water interface, facilitating the self-assembly of a phospholipid bilayer. In addition, for the first time we have studied the mechanical properties of the resultant lipid bilayers of the microfluidic GUVs. Using fluctuation analysis we were able to calculate the values for bending rigidity of giant vesicles assembled on chip and demonstrate that these correlate strongly with those of traditional low throughput strategies such as electroformation.

Microfluidic generation of droplet interface bilayer networks incorporating real-time size sorting in linear and non-linear configurations.

In this study, a novel droplet based microfluidic method for the generation of different sized droplet interface bilayers is reported. A microfluidic platform was designed, which allows the generation and packing of picoliter lipid coated water droplets. Droplets were generated by hydrodynamic focusing coupled with selective transport along grooves according to their size. A trapping structure at the end of the groove and a fine control of the flow pressures allowed for the droplets to be successfully trapped and aligned on demand. This technology facilitates the fine control of droplet size production as well as the generation of extended networks from a variety of lipids including 1,2-diphytanoyl-sn-glycero-3-phosphocholine and 1,2-dioleoyl-sn-glycero-3-phosphocholine in linear and non-linear configurations, which is vital to the application of Droplet Interface Bilayers to biological network construction on-chip.

Incidents of potential public health significance identified using national surveillance of US poison center data (2008-2012).

BACKGROUND: The Centers for Disease Control and Prevention (CDC) and the American Association of Poison Control Centers conduct national surveillance on data collected by US poison centers to identify incidents of potential public health significance (IPHS). The overarching goals of this collaboration are to improve CDC's national surveillance capacity for public health threats, identify early markers of public health incidents and enhance situational awareness. The National Poison Data System (NPDS) is used as a surveillance system to automatically identify data anomalies. PURPOSE: To characterize data anomalies and IPHS captured by national surveillance of poison center data over 5 years. METHODS: Data anomalies are identified through three surveillance methodologies: call-volume, clinical effect, and case-based. Anomalies are reviewed by a team of epidemiologists and clinical toxicologists to determine IPHS using standardized criteria. The authors reviewed IPHS identified by these surveillance activities from 2008 through 2012. RESULTS: Call-volume surveillance identified 384 IPHS; most were related to gas and fume exposures (n = 229; 59.6%) with the most commonly implicated substance being carbon monoxide (CO) (n = 92; 22.8%). Clinical-effect surveillance identified 138 IPHS; the majority were related to gas and fume exposures (n = 58; 42.0%) and gastrointestinal complaints (n = 84; 16.2%), and the most commonly implicated substance was CO (n = 20; 14.4%). Among the 11 case-based surveillance definitions, the botulism case definition yielded the highest percentage of identified agent-specific illness. CONCLUSIONS: A small proportion of data anomalies were designated as IPHS. Of these, CO releases were the most frequently reported IPHS and gastrointestinal syndromes were the most commonly reported illness manifestations. poison center data surveillance may be used as an approach to identify exposures, illnesses, and incidents of importance at the national and state level.

Crystallisation in oxide glasses - a tutorial review.

Glasses and glass-ceramics have had a tremendous impact upon society and continue to have profound industrial, commercial and domestic importance. A remarkable number of materials, with exceptional optical and mechanical properties, have been developed and enhanced using the glass-ceramic method over many years. In order to develop glass-ceramics, glass is initially prepared via high temperature synthesis and subsequently heat treated, following a carefully designed and controlled process. A glass-ceramic system comprises crystalline and non-crystalline phases; in multicomponent systems these phases are significantly different from the initial glass composition. The properties of glass-ceramics are defined by microstructure, crystal morphology as well as the final chemical composition and physical properties of the residual glass. Knowing the mechanism of glass crystallisation, it is possible to predict and design a glass-ceramic system with near-ideal properties that exactly fulfil the requirements for a particular application. This tutorial review is a basic introduction to the crystallisation in glasses and mainly focuses on silicate and closely related oxide glasses. The review describes and discusses key learning points in five different sections, which facilitate the understanding of glass crystallisation and development of glass-ceramics.