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We present our work about the development of two complementary interrogation schemes based on fiber optic sensing for the use of structural and thermal monitoring of Ariane launchers. The advantages of fiber optic sensing in particular light-weight, immunity to electromagnetic interferences and the possibility of sensor distribution along optical fibers are driving factors for utilization of this technology in space crafts [1]. The edge-filter (EF) and scanning-laser (SL) interrogators for determination of the mean wavelength of fiber Bragg grating (FBG) sensors have been implemented as two separate demonstrators. Within this paper we describe the functional principles of both interrogators. Furthermore we present test results where the developed systems have been used for readout of FBG sensors which are implemented in an Ariane structural demonstrator during thermal, thermal-vacuum and vibration tests. Functionality of both systems is demonstrated and their potential for further development towards space qualified systems is shown. Since the performance characteristics of the two systems are different from each other, they are dedicated for different sensing applications on a launcher. The EF sensor interrogator provides a sample rate of 20 kHz at a number of 4 connected sensors and supports parallel readout and aliasing free operation. Therefore it is best suited for high priority measurement. Structural monitoring which requires the acquisition of real time sensor information in order to support control of the launcher is one operation area for a future EF system. The SL interrogator provides an overall measurement rate of 1 kHz at a number of 24 connected sensors distributed on three sensor channels. It can be adapted to any sensors that have design wavelengths lying within the output spectrum of the laser diode. Furthermore the number of overall sensors to be read out with this system can be adapted easily. Thermal mapping of satellite panels is one possible future application for the SL interrogator.

Layered (oxy) hydroxide minerals often possess out-of-plane hydrogen atoms that form hydrogen bonding networks which stabilize the layered structure. However, less is known about how the ordering of these bonds affects the structural stability and solubility of these minerals. Here, we report a new strategy that uses the focused electron beam to probe the effect of differences in hydrogen bonding networks on mineral solubility. In this regard, the dissolution behavior of boehmite (γ-AlOOH) and gibbsite (γ-Al(OH)3) were compared and contrasted in real time via liquid cell electron microscopy. Under identical such conditions, 2D-nanosheets of boehmite (γ-AlOOH) exfoliated from the bulk and then rapidly dissolved, whereas gibbsite was stable. Further, substitution of only 1% Fe(III) for Al(III) in the structure of boehmite inhibited delamination and dissolution. Factors such as pH, radiolytic species, and knock on damage were systematically studied and eliminated as proximal causes for boehmite dissolution. Instead, the creation of electron/hole pairs was considered to be the mechanism that drove dissolution. The widely disparate behaviors of boehmite, gibbsite, and Fe-doped boehmite are discussed in the context of differences in the OH bond strengths, hydrogen bonding networks, and the presence or absence of electron/hole recombination centers.

Per- and polyfluoroalkyl substances (PFAS) are a group of fluorinated substances that are in the focus of researchers and regulators due to widespread presence in the environment and biota, including humans, of perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA). Fluoropolymers, high molecular weight polymers, have unique properties that constitute a distinct class within the PFAS group. Fluoropolymers have thermal, chemical, photochemical, hydrolytic, oxidative, and biological stability. They have negligible residual monomer and oligomer content and low to no leachables. Fluoropolymers are practically insoluble in water and not subject to long-range transport. With a molecular weight well over 100 000 Da, fluoropolymers cannot cross the cell membrane. Fluoropolymers are not bioavailable or bioaccumulative, as evidenced by toxicology studies on polytetrafluoroethylene (PTFE): acute and subchronic systemic toxicity, irritation, sensitization, local toxicity on implantation, cytotoxicity, in vitro and in vivo genotoxicity, hemolysis, complement activation, and thrombogenicity. Clinical studies of patients receiving permanently implanted PTFE cardiovascular medical devices demonstrate no chronic toxicity or carcinogenicity and no reproductive, developmental, or endocrine toxicity. This paper brings together fluoropolymer toxicity data, human clinical data, and physical, chemical, thermal, and biological data for review and assessment to show that fluoropolymers satisfy widely accepted assessment criteria to be considered as "polymers of low concern" (PLC). This review concludes that fluoropolymers are distinctly different from other polymeric and nonpolymeric PFAS and should be separated from them for hazard assessment or regulatory purposes. Grouping fluoropolymers with all classes of PFAS for "read across" or structure-activity relationship assessment is not scientifically appropriate. Integr Environ Assess Manag 2018;14:316-334. © 2018 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals, Inc. on behalf of Society of Environmental ToxicologyChemistry (SETAC).

In view of the ESA-CONAE SAOCOM-CS L-band bistatic SAR mission this paper will present, analysis of geometric parameters impact on tomographic processing, discussing questions related to vertical resolution, baseline sampling and interferometric phase calibration in the context of bistatic acquisitions. L-band tomographic processing experiments on real data will be also presented exploiting available ESA SAR airborne campaign images. The amount of computational speed improvement when performing the tomographic algorithms in parallel environment will be also addressed. Furthermore, specific analysis concerning the extension to a possible similar bistatic mission for Sentinel 1 C-band data will be also addressed addressing the TOPS mode impact on tomographic processing.

Most species aggregate in local patches. High host density in patches increases contact rate between hosts and parasites, increasing parasite transmission success. At the same time, for environmentally transmitted parasites, high host density can decrease infection risk to individual hosts, because infective stages are divided among all hosts in a patch, leading to safety in numbers. We tested these predictions using the California horn snail, Cerithideopsis californica (=Cerithidea californica), which is the first intermediate host for at least 19 digenean trematode species in California estuaries. Snails become infected by ingesting trematode eggs or through penetration by free-swimming miracidia that hatch from trematode eggs deposited with final-host (bird or mammal) feces. This complex life cycle decouples infective-stage production from transmission, raising the possibility of an inverse relationship between host density and infection risk at local scales. In a field survey, higher snail density was associated with increased trematode (infected snail) density, but decreased trematode prevalence, consistent with either safety in numbers, parasitic castration, or both. To determine the extent to which safety in numbers drove the negative snail-density-trematode-prevalence association, we manipulated uninfected snail density in 83 cages at eight sites within Carpinteria Salt Marsh (California, USA). At each site, we quantified snail density and used data on final-host (bird and raccoon) distributions to control for between-site variation in infective-stage supply. After three months, overall trematode infections per cage increased with snail biomass density. For egg-transmitted trematodes, per-snail infection risk decreased with snail biomass density in the cage and surrounding area, whereas per-snail infection risk did not decrease for miracidium-transmitted trematodes. Furthermore, both trematode recruitment and infection risk increased with infective-stage input, but this was significant only for miracidium-transmitted species. A model parameterized with our experimental results and snail densities from 524 field transects estimated that safety in numbers, when combined with patchy host density, halved per capita infection risk in this snail population. We conclude that, depending on transmission mode, host density can enhance parasite recruitment and reduce per capita infection risk.

6:2 fluorotelomer alcohol (6:2 FTOH) was evaluated for potential systemic repeated-dose and reproductive toxicity in mice. 6:2 FTOH was administered by oral gavage to CD-1 mice as a suspension in 0.5% aqueous methylcellulose with 0.1% Tween-80 at dosages of 1, 5, 25, or 100 mg/kg/day. The no-observed-adverse-effect level (NOAEL) for systemic toxicity was 25 mg/kg/day (males) and 5 mg/kg/day (females), based on effects at higher doses on mortality, clinical observations, body weight, nutritional parameters, hematology (red and white blood cell), clinical chemistry (liver-related), liver weights, and histopathology (liver, teeth, reproductive tract, and mammary gland). However, 6:2 FTOH was not a selective reproductive toxicant. The NOAEL for reproductive toxicity was >100 mg/kg/day; no effects on reproductive outcome were observed at any dosage. The NOAEL for viability and growth of the offspring was 25 mg/kg/day, based on clinical signs of delayed maturation in pups, and reductions in pup survival and pup body weight during lactation at 100 mg/kg/day. While the severity of the effects was generally greater in mice than previously reported in CD rats, the overall NOAELs were identical in both species, 5 mg/kg/day for systemic toxicity and 25 mg/kg/day for offspring viability/growth. 6:2 FTOH was not a selective reproductive toxicant in either species; no effects on reproductive outcome occurred at any dose level, and any effects observed in offspring occurred at dose levels that induced mortality and severe toxicity in maternal animals.

Free-living stages of parasites are consumed by a variety of predators, which might have important consequences for predators, parasites, and hosts. For example, zooplankton prey on the infectious stage of the amphibian chytrid fungus, Batrachochytrium dendrobatidis (Bd), a pathogen responsible for amphibian population declines and extinctions worldwide. Predation on parasites is predicted to influence community structure and function, and affect disease risk, but relatively few studies have explored its consequences empirically. We investigated interactions among Rana cascadae tadpoles, zooplankton, and Bd in a fully factorial experiment in outdoor mesocosms. We measured growth, development, survival, and infection of amphibians and took weekly measurements of the abundance of zooplankton, phytoplankton (suspended algae), and periphyton (attached algae). We hypothesized that zooplankton might have positive indirect effects on tadpoles by consuming Bd zoospores and by consuming phytoplankton, thus reducing the shading of a major tadpole resource, periphyton. We also hypothesized that zooplankton would have negative effects on tadpoles, mediated by competition for algal resources. Mixed-effects models, repeated-measures ANOVAs, and a structural equation model revealed that zooplankton significantly reduced phytoplankton but had no detectable effects on Bd or periphyton. Hence, the indirect positive effects of zooplankton on tadpoles were negligible when compared to the indirect negative effect mediated by competition for phytoplankton. We conclude that examination of host-pathogen dynamics within a community context may be necessary to elucidate complex community dynamics.

Counselors cannot offer what they do not have. In a society marked by round-the-clock connectivity, it is difficult to set aside personal time to recharge and reflect. Yet the minds, voices, bodies, and spirits of counselors are our healing instruments. If even one component is weakened, a slow leak springs. Without an intentional practice of alonetime—a devoted period in silence and solitude or reflectively within oneself when in a group—the cost may be a life vocation unnecessarily lost, or even worse. We will examine priorities and common resistances; consider what alonetime may already be available but possibly underused; evaluate places that may promote a more reflective spirit; offer suggestions on how to restructure a busy schedule; and suggest alonetime and mindfulness meditation resources.

6:2 Fluorotelomer iodide [6:2 FTI, F(CF2)(6)CH2CH2I] is the industrial raw material used to manufacture 6:2 fluorotelomer alcohol [6:2 FTOH, F(CF2)(6)CH2CH2OH] and 6:2 FTOH-based products. During its manufacture and industrial use, workers may be exposed to via oral, dermal or inhalation of 6:2 FTI. Therefore it is useful to understand how 6:2 HI may be metabolized and into what transformation products. 6:2 FTI in vitro rat liver microsomal metabolism was explored for the first time to compare its biotransformation potential with that of [1,2-C-14] 6:2 FTOH [F(CF2)(6)(CH2CH2OH)-C-14-C-14]. 6:2 FTI and 6:2 FTOH metabolite yields were determined in closed-bottle systems using Sprague Dawley and Wistar Han rat microsomes after incubation at 37 C for up to 6 h with NADPH (reduced form of nicotinamide adenine dinucleotide phosphate)-addition and NADPH-regenerating systems, respectively. 5:3 acid [F(CF2)(5)CH2CH2COOH] was the most abundant metabolite for 6:2 FTI (3.3-6.3 mol%) and 6:2 FTOH (9-12 mol%). Perfluorobutanoic acid (PFBA), perfluoropentanoic acid (PFPeA), and perfluorohexanoic acid (PFHxA) in sum accounted for 1.3-2.2 mol% from 6:2 FTI and 2.7-4.4 mol% from 6:2 FTOH biotransformation. Perfluoroheptanoic acid (PFHpA) accounted for 0.14-0.36 mol% from 6:2 FTI but only 0.01-0.06 mol% from 6:2 FTOH biotransformation. These results suggest that mammalian systems exposed to 6:2 FTI or 6:2 FTOH would form 5:3 acid, PFBA, PFPeA, PFHxA as the primary stable metabolites, whereas more PFHpA would be expected from 6:2 FTI biotransformation. (C) 2014 Elsevier Ltd. All rights reserved.

A bistatic radar at X-band (11 GHz) using opportunity signals (Passive Reflectometry and Interferometry System (PARIS) concept implementing the interferometric technique) has been developed and tested in a coastal-based experimental setup. Digital satellite TV signals broadcast from geostationary orbit have been used as sources of opportunity, and correlation waveforms have been collected at different receiver bandwidths. Calibration algorithms to compensate instrumental errors have improved our observables and allowed us to obtain delay measurements with a precision of about 10 cm for wind speeds in the range of 3 m/s. A statistical analysis of the measurement noise is used to determine the quality of the obtained observables. This paper also discusses the opportunities of the PARIS concept applied at higher frequency band and with stronger signals.

The occurrence of plutonium dioxide (PuO2) either from direct deposition or from the precipitation of plutonium-bearing solutions in contaminated soils and sediments has been well described, particularly for the Hanford site in Washington State. However, past research has suggested that plutonium may exist in environmental samples at the Hanford site in chemical forms in addition to large size PuO2 particles and that these previously unidentified nano-sized particles maybe more reactive and thus more likely to influence the environmental mobility of Pu. Here we present evidence for the formation of nano-sized plutonium iron phosphate hydroxide structurally related to the rhabdophane group nanoparticles in 216-Z9 crib sediments from Hanford using transmission electron microscopy (TEM). The distribution and nature of these nanoparticles varied depending on the adjacent phases present. Fine electron probes were used to obtain electron diffraction and electron energy-loss spectra from specific phase regions of the 216-Z9 cribs specimens from fine-grained plutonium oxide and phosphate phases. Energy-loss spectra were used to evaluate the plutonium N4,5 (4d → 5f ) and iron L2,3 absorption edges. The iron plutonium phosphate formation may depend on the local micro-environment in the sediments, availability of phosphate, and hence the distribution of these minerals may control long-termmore » migration of Pu in the soil. This study also points to the utility of using electron beam methods for determining the identity of actinide phases and their association with other sediment phases.« less

The uranium–molybdenum (U–Mo) alloy in a monolithic form has been proposed as one fuel design capable of converting some of the world’s highest power research reactors from the use of high enriched uranium to low enriched uranium. One aspect of the fuel development and qualification process is to demonstrate appropriate understanding of the thermal-conductivity behavior of the fuel system as a function of temperature and expected irradiation conditions. The purpose of this paper is to verify functionality of equipment installed in hot cells for eventual measurements on irradiated uranium–molybdenum (U–Mo) monolithic fuel specimens, refine procedures to operate the equipment, and validate models to extract the desired thermal properties. The results presented here demonstrate the adequacy of the equipment, procedures, and models that have been developed for this purpose based on measurements conducted on surrogate depleted uranium–molybdenum (DU–Mo) alloy samples containing a Zr diffusion barrier and clad in aluminum alloy 6061 (AA6061). The results are in excellent agreement with thermal property data reported in the literature for similar U–Mo alloys as a function of temperature.

Rat models have emerged as a common tool to study neuroinflammation to intracortical microelectrodes. While a number of studies have attempted to understand the factors resulting in neuroinflammation using rat models, a complete understanding of key mechanistic pathways remains elusive. Transgenic mouse models, however, could facilitate a deeper understanding of mechanistic pathways due to an ease of genetic alteration. Therefore, the goal of the present study is to compare neuroinflammation following microelectrode implantation s between the rat and the mouse model. Our study suggests that subtle differences in the classic neuroinflammatory markers exist between the animal models at both two and sixteen weeks post implantation. Most notably, neuronal densities surrounding microelectrodes were significantly lower in the rat model at two weeks, while similar densities were observed between the animal models at sixteen weeks. Physiological differences between the species and slight alterations in surgical methods are likely key contributors to the observed differences. Moving forward, we propose that differences in the time course of neuroinflammation between the animal models should be considered when trying to understand and prevent intracortical microelectrode failure.

Nitrogen trifluoride (NF3) was used to fluorinate the metallic residue from the dissolution of a high burnup, boiling water reactor fuel (∼70 MWd/kgU). The washed residue included the noble-metal phase (containing ruthenium, rhodium, palladium, technetium, and molybdenum), smaller amounts of zirconium, selenium, tellurium, and silver, along with trace quantities of plutonium, uranium, cesium, cobalt, europium, and americium, likely as their oxides. Exposing the noble metal phase to 10% NF3 in argon, between 400 and 550 °C, removed molybdenum and technetium near 400 °C as their volatile fluorides, and ruthenium near 500 °C as its volatile fluoride. The events were thermally and temporally distinct and the conditions specified provide a recipe to separate these transition metals from each other and from the nonvolatile residue. Depletion of the volatile fluorides resulted in substantial exothermicity. Thermal excursion behavior was recorded with the thermal gravimetric instrument operated in a non-adiabatic, isothermal mode; conditions that typically minimize heat release. Physical characterization of the noble-metal phase and its thermal behavior are consistent with high kinetic velocity reactions encouraged by the nanoparticulate phase or perhaps catalytic influences of the mixed platinum metals with nearly pure phase structure. Post-fluorination, only two products were present in the residual nonvolatile fraction. These were identified as a nano-crystalline, metallic palladium cubic phase and a hexagonal rhodium trifluoride (RhF3) phase. The two phases were distinct as the sub-μm crystallites of metallic palladium were in contrast to the RhF3 phase, which grew from the parent, nano-crystalline noble-metal phase during fluorination, to acicular crystals exceeding 20-μm in length.

The solubility of different forms of precipitated 242PuO2(am) were examined in solutions containing aqueous Fe(II) over a range of pH values. The first series of 242PuO2(am) suspensions were prepared from a 242Pu(IV) stock that had been treated with thenoyltrifluoroacetone (TTA) to remove the 241Am originating from the decay of 241Pu. These 242PuO2(am) suspensions showed much higher solubilities at the same pH value and Fe(II) concentration than previous studies using 239PuO2(am). X-ray absorption fine structure (XAFS) spectroscopy of the precipitates showed a substantially reduced Pu–Pu backscatter over that previously observed in 239PuO2(am) precipitates, indicating that the 242PuO2(am) precipitates purified using TTA lacked the long range order previously found in239PuO2(am) precipitates. The Pu(IV) stock solution was subsequently repurified using an ion exchange resin and an additional series of 242PuO2(am) precipitates prepared. These suspensions showed higher redox potentials and total aqueous Pu concentrations than the TTA purified stock solution. The higher redox potential and aqueous Pu concentrations were in general agreement with previous studies on 242PuO2(am) precipitates, presumably due to the removal of possible organic compounds originally present in the TTA purified stock. 242PuO2(am) suspensions prepared with both stock solutions showed almost identical solubilities in Fe(II) containing solutions even though the initial aqueous Pu concentrations before the addition of Fe(II) were orders of magnitude different. By examining the solubility of 242PuO2(am) prepared from both stocks in this way we have essentially approached equilibrium from both the undersaturated and oversaturated conditions. The final aqueous Pu concentrations are predictable using a chemical equilibrium model which includes the formation of a nanometer sized Fe(III) reaction product, identified in the 242PuO2(am) suspension both by use of 57Fe Mössbauer spectroscopy and transmission electron microscopy (TEM) analysis.

Three different chemical treatment methods were tested for their ability to stabilize residual waste from Hanford tank C-202 for reducing contaminant release (Tc, Cr, and U in particular). The three treatment methods tested were lime addition [Ca(OH)2], an in situ Ceramicrete waste form based on chemically bonded phosphate ceramics, and a ferrous iron/goethite treatment. These approaches rely on formation of insoluble forms of the contaminants of concern (lime addition and Ceramicrete) and chemical reduction followed by co-precipitation (ferrous iron/goethite incorporation treatment). The results have demonstrated that release of uranium from tank residual wastes can be dramatically reduced after treatment compared to contact with simulated grout porewater without treatment. All three treatments methods reduced the leachable uranium concentrations by well over three orders of magnitude. In the case of uranium and technetium, released concentrations were well below their respective Maximum Contaminant Levels (MCLs) for the wastes tested. For tank C-202 residual waste, chromium release concentrations were above the MCL but were considerably reduced relative to untreated tank waste. This innovative approach has the potential to revolutionize Hanford’s tank retrieval process, by allowing larger volumes of residual waste to be left in tanks while providing an acceptably low level of risk with respect to contaminant release that is protective of the environment and human health. Such an approach could enable DOE to realize significant cost savings through streamlined retrieval and closure operations.

Major fluorinated chemical manufacturers have developed new short-chain per- and polyfluorinated substances with more favorable environmental, health and safety profiles. This study provides the first evaluation of the elimination half-life of perfluorohexanoic acid (PFHxA) from the blood of humans. PFHxA biomonitoring data were obtained from a recently published study of professional ski wax technicians. These data were analyzed to provide estimates of the apparent half-life of PFHxA from humans, and comparisons were made with kinetic studies of PFHxA elimination from mice, rats and monkeys. The apparent elimination half-life of PFHxA in highly exposed humans ranged between 14 and 49 d with a geomean of 32 d. The half-lives of PFHxA in mice, rats, monkeys and humans were proportional to body weight with no differences observed between genders, indicating similar volumes of distribution and similar elimination mechanisms among mammalian species. Compared to long-chain perfluoroalkyl acid analogs, PFHxA is rapidly cleared from biota. The consistent weight-normalized elimination half-lives for PFHxA in mammalian species indicates that results obtained from animal models are suitable for establishment of PFHxA benchmark dose and reference dose hazard endpoints for use in human risk assessments.

The reduction of PuO2(am) by Fe(II) in the presence and absence of hematite was studied over a range of pH values and oxidation/reduction potentials. In contrast to thermodynamic predictions, the presence of hematite did not have a major effect on the overall reduction of PuO2(am) to aqueous Pu(III). Instead the aqueous Pu(III) concentrations at longer time frames were accurately predicted using the measured Fe(II) concentration and existing thermodynamic data for the reaction: H2O + H++ Fe2++ PuO2(am) ⇌ Pu3++ Fe(OH)3(am) with log K =− 0.6. The accuracy of this approach in all solutions containing aqueous Fe(II), coupled with the apparent lack of oxidation of Fe(II) by O2(g), suggests that the Fe(OH)3(am) is formed by the oxidation of Fe(II) to Fe(III) by radiolysis. The continued generation of reactive amorphous iron hydroxide by radiolysis prevents thermodynamic equilibrium from being reached with more stable ferric oxide compounds, except possibly under acidic conditions where amorphous ferric hydroxide is soluble. The use of measured pe values, instead of aqueous Fe(II) measurements, also yields reasonable predictions of the final Pu(III) concentrations although the predictions are more uncertain.

6:2 FTI [F(CF2)6CH2CH2I] is a principal industrial raw material used to manufacture 6:2 FTOH [F(CF2)6CH2CH2OH] and 6:2 FTOH-based products and could enter aerobic environments from possible industrial emissions where it is manufactured. This is the first study to assess 6:2 FTI aerobic soil biotransformation, quantify transformation products, and elucidate its biotransformation pathways. 6:2 FTI biotransformation led to 6:2 FTOH as a key intermediate, which was subsequently biotransformed to other significant transformation products, including PFPeA [F(CF2)4COOH, 20 mol % at day 91], 5:3 acid [F(CF2)5CH2CH2COOH, 16 mol %], PFHxA [F(CF2)5COOH, 3.8 mol %], and 4:3 acid [F(CF2)4CH2CH2COOH, 3.0 mol %]. 6:2 FTI biotransformation also led to a significant level of PFHpA [F(CF2)6COOH, 16 mol % at day 91], perhaps via another putative intermediate, 6:2 FTUI [F(CF2)6CH ═ CHI], whose molecular identity and further biotransformation were not verified because of the lack of an authentic standard. Total recovery of the aforementioned per- and polyfluorocarboxylates accounted for 59 mol % of initially applied 6:2 FTI by day 91, in comparison to 56 mol % when soil was dosed with 6:2 FTOH, which did not lead to PFHpA. Thus, were 6:2 FTI to be released from its manufacture and undergo soil microbial biotransformation, it could form PFPeA, PFHpA, PFHxA, 5:3 acid, and 4:3 acid in the environment.

The current study seeks to elucidate a biological mechanism which may mediate neuroinflammation, and decreases in both blood–brain barrier stability and neuron viability at the intracortical microelectrode-tissue interface. Here, we have focused on the role of pro-inflammatory reactive oxygen species. Specifically, adult rats implanted within intracortical microelectrodes were systemically administered the anti-oxidant, resveratrol, both the day before and the day of surgery. Animals were sacrificed at two or four weeks post-implantation for histological analysis of the neuroinflammatory and neurodegenerative responses to the microelectrode. At two weeks post-implantation, we found animals treated with resveratrol demonstrated suppression of reactive oxygen species accumulation and blood–brain barrier instability, accompanied with increased density of neurons at the intracortical microelectrode-tissue interface. Four weeks post-implantation, animals treated with resveratrol exhibited indistinguishable levels of markers for reactive oxygen species and neuronal nuclei density in comparison to untreated control animals. However, of the neurons that remained, resveratrol treated animals were seen to display reductions in the density of degenerative neurons compared to control animals at both two and four weeks post-implantation. Initial mechanistic evaluation suggested the roles of both anti-oxidative enzymes and toll-like receptor 4 expression in facilitating microglia activation and the propagation of neurodegenerative inflammatory pathways. Collectively, our data suggests that short-term attenuation of reactive oxygen species accumulation and blood–brain barrier instability can result in prolonged improvements in neuronal viability around implanted intracortical microelectrodes, while also identifying potential therapeutic targets to reduce chronic intracortical microelectrode-mediated neurodegeneration.

For the past several decades, amphibian populations have been decreasing around the globe at an unprecedented rate. Batrachochytrium dendrobatidis (Bd), the fungal pathogen that causes chytridiomycosis in amphibians, is contributing to amphibian declines. Natural and anthropogenic environmental factors are hypothesized to contribute to these declines by reducing the immunocompetence of amphibian hosts, making them more susceptible to infection. Antimicrobial peptides (AMPs) produced in the granular glands of a frog's skin are thought to be a key defense against Bd infection. These peptides may be a critical immune defense during metamorphosis because many acquired immune functions are suppressed during this time. To test if stressors alter AMP production and survival of frogs exposed to Bd, we exposed wood frog (Lithobates sylvaticus) tadpoles to the presence or absence of dragonfly predator cues crossed with a single exposure to three nominal concentrations of the insecticide malathion (0, 10, or 100 parts per billion (ppb)). We then exposed a subset of post-metamorphic frogs to the presence or absence of Bd zoospores and measured frog survival. Although predator cues and malathion had no effect on survival or size at metamorphosis, predator cues increased the time to metamorphosis by 1.5 days and caused a trend of a 20% decrease in hydrophobic skin peptides. Despite this decrease in peptides determined shortly after metamorphosis, previous exposure to predator cues increased survival in both Bd-exposed and unexposed frogs several weeks after metamorpho- sis. These results suggest that exposing tadpoles to predator cues confers fitness benefits later in life.

6:2 Fluorotelomer alcohol [6:2 FTOH, F(CF2)6CH2CH2OH] is a major basic chemical being used to manufacture FTOH-based products. After the end of use, 6:2 FTOH-based products may be released to domestic wastewater treatment plants (WWTPs) as a first major environmental entry point. Activated sludge collected from two WWTPs was dosed with 6:2 FTOH to investigate its biotransformation rate and to identify major transformation products. The volatile 5:2 sFTOH [F(CF2)5CH(OH)CH3] is the most abundant transformation product and accounted for an average of 40 mol% of initially dosed 6:2 FTOH after two months of incubation with activated sludge, with 30 mol% detected in the headspace. PFPeA [F(CF2)4COOH] averaged 4.4 mol% after two months, 2.4–7 times lower than that in sediment and soils. The much lower level of PFPeA formed in activated sludge compared with soil indicates that microbial populations in activated sludge may lack enzymes or suitable environment conditions to promote rapid 5:2 sFTOH decarboxylation to form PFPeA, resulting in more 5:2 sFTOH partitioned to the headspace. PFHxA [F(CF2)5COOH] and 5:3 [F(CF2)5CH2CH2COOH] acid are major non-volatile transformation products in activated sludge. For example, PFHxA averaged 11 mol% after two months, which is about 30% higher compared with sediment and soils, suggesting that microbes in WWTPs may utilize similar pathways as that in sediment and soils to convert 5:2 sFTOH to PFHxA. 5:3 Acid averaged 14 mol% after two months, comparable to that in soils and slightly lower than in sediment, further confirming that 5:3 acid is a unique product of 6:2 FTOH biotransformation in the environment.

6:2 FTOH and 8:2 FTOH [FTOHs, F(CF2)nCH2CH2OH, n = 6, 8] are the principal polyfluorinated raw materials used to manufacture FTOH-based products, which may be released to WWTPs during their product life cycle. For the first time, anaerobic biotransformation of FTOHs and key biotransformation intermediates in WWTP digester sludge under methanogenic conditions was investigated. 6:2 FTOH was transformed to 6:2 FTCA, [F(CF2)6CH2COOH, 32-43 mol %], 6:2 FTUCA [F(CF2)5CF═CHCOOH, 1.8-8.0 mol %], and 5:3 acid [F(CF2)5CH2CH2COOH, 18-23 mol %] by day 90 and day 176 in two separate studies. 8:2 FTOH was transformed by day 181 to 8:2 FTCA (18 mol %), 8:2 FTUCA (5.1 mol %), and 7:3 acid (27 mol %). 6:2 and 8:2 FTOH anaerobic biotransformation led to low levels of perfluorohexanoic acid (PFHxA, ≤0.4 mol %) and perfluorooctanoic acid (PFOA, 0.3 mol %), respectively. 6:2 FTUCA anaerobic biotransformation led to a newly identified novel transient intermediate 3-fluoro 5:3 acid [F(CF2)5CFHCH2COOH] and 5:3 acid, but not 5:2 sFTOH [F(CF2)5CH(OH)CH3] and α-OH 5:3 acid [F(CF2)5CH2CH(OH)COOH], two precursors leading to PFPeA (perfluoropentanoic acid) and PFHxA. Thus, FTOH anaerobic biotransformation pathways operated by microbes in the environment was likely inefficient at shortening carbon chains of FTOHs to form PFCAs (perfluorinated carboxylic acids). These results imply that anaerobic biotransformation of FTOH-based products may produce polyfluorinated acids, but is not likely a major source of PFCAs detected in anaerobic environmental matrices such as anaerobic digester sludge, landfill leachate, and anaerobic sediment under methanogenic conditions.

Amorphous TcO2 and NH4TcO4 solubilized into 12 M HCl will spontaneously convert to hexachlorotechnetate (TcCl6 2−). This process is accelerated upon heating but species lower than Tc(IV) are not generated by this action. TcCl6 2− is kinetically unstable with regards to formation in solutions of low concentrations of HCl and will spontaneously convert back to soluble and insoluble forms of Tc(IV) in water. TcCl6 2− in 12 M HCl placed in contact with the reducing metal Zn at elevated temperatures (90 °C) forms a black precipitate that contains amorphous Tc metal, TcO2, and oxy-chlorides of Tc. Powder X-ray diffraction indicates the presence of Tc metal after thermal treatment where X-ray absorption fine structure spectroscopy indicates the presence of hexagonal Tc metal and amorphous TcO2 in the precipitate after rinsing with 12 HCl but before thermal treatment. The resulting solution contains a mixture of Tc chlorides and oxy-chlorides following reduction where TcCl6 2− is completely consumed resulting primarily in Tc2OCl10 4− dominating the UV–visible spectra. Reducing the solution volume and reconstituting the products into 12 M HCl while boiling the mixed solution (>24 h) will slowly convert all soluble Tc back to TcCl6 2−. Expanding on previous efforts made in this laboratory to recover Tc metal from aqueous solution, we investigate its synthesis when Tc(IV) and Tc(VII) in 12 M HCl is placed in contact with the reducing metal (i.e., Zn) at elevated temperatures.

SummaryWith challenges in the healthcare system growing, strengthened leader and organizational resilience is often overlooked as a factor that can support staff morale and sustain performance improvement and quality. Here we examine resilience-building practices related to self-awareness, alone time, mindfulness, and a healthy perspective.A key aspect of management resilience is weighing the costs and benefits to the executive personally and to the organization if the warning signals of impairment are left untended. To that end, we propose a leader self-care protocol, which even the busy healthcare executive can find time to undertake. If implemented, the protocol will allow leaders to lessen their vulnerability to burnout and help teammates whose resilience may be stretched thin. Finally, we present healthy coping skills for daily stressors and for the sudden and overwhelming situations that can negatively affect resilience.Modern leaders are charged with casting a compelling vision, mobilizing their staff to accomplish great things, offering hope in the midst of traumatic circumstances, modeling exemplary client care, and delivering on the bottom line- all while exhibiting the highest levels of integrity, optimism, and innovation. In the constantly changing healthcare field, the added complexity is that many of the clients are ill and our employees are trying to help them feel better not only physically but psychologically and emotionally as well. Add to that the fact that this is all being achieved while managing the incremental, and sometimes transformative, change of the system as a whole so it can remain financially vital.In fact, healthcare is one of the only remaining professions in which ignoring spouses, significant others, children, friends, and even ourselves is still considered socially acceptable. A woman physician once noted, "What's good about caring for others is that there is always something to do, so you don't have to think about your problems. What's bad about caring for others is that there's always something to do so you don't have to think about your problems enough" (Wicks 2010). The same can surely be said of healthcare executives, who must balance the delivery of safe and effective patient care with so many other significant operational factors.If we healthcare executives are honest with ourselves, as is the case with most of us guiding policy and action in the healing professions, we are not psychologically or spiritually home much of the FRONTIERS OF HEALTH SERVICES M A N A G E M E N T 3 O : 2time. However, as leaders faced with daily challenges that have life-and-death consequences, we risk professional and personal catastrophe if we disengage from our staff, our patients, and ourselves.Healthy, resilient executives set a positive tone for their organizations and energize their employees by fostering high staff morale and professional development while driving sustainable performance improvement and quality. These are the linchpins of transformative change when it becomes necessary-which is often the case in today's challenging healthcare scene. Thus, it is important to address resilience and weigh the costs and benefits to the executive personally and to the organization if the warning signals of impairment are left untended. This approach requires healthy coping skills for the day-to-day work life as well as the sudden, overwhelming situations that challenge resilience.In this article, we share the essential factors in strengthening a self-care protocol, including self-awareness, sensitivity to renewing alone time that is already present but not fully appreciated, mindfulness, and a healthy perspective. Resilience is not simply bouncing back from stress; it is both recovering and deepening as a consequence of encountering stress in the right way with adequate inner strength.The Resilience Factor in BusinessMedicine, nursing, and healthcare are very emotional businesses. …

Contaminant release models are required to evaluate and predict long-term environmental impacts of even residual amounts of high-level radioactive waste after cleanup and closure of radioactively contaminated sites such as the DOE’s Hanford Site. More realistic and representative models have been developed for release of uranium, technetium, and chromium from Hanford Site tanks C-202, C-203, and C-103 residual wastes using data collected with a single-pass flow-through test (SPFT) method. These revised models indicate that contaminant release concentrations from these residual wastes will be considerably lower than previous estimates based on batch experiments. For uranium, a thermodynamic solubility model provides an effective description of uranium release, which can account for differences in pore fluid chemistry contacting the waste that could occur through time and as a result of different closure scenarios. Under certain circumstances in the SPFT experiments various calcium rich precipitates (calcium phosphates and calcite) form on the surfaces of the waste particles, inhibiting dissolution of the underlying uranium phases in the waste. This behavior was not observed in previous batch experiments. For both technetium and chromium, empirical release models were developed. In the case of technetium, release from all three wastes was modeled using an equilibrium Kd model. Formore » chromium release, a constant concentration model was applied for all three wastes.« less

Laves-type intermetallic phases have been observed to be the dominant phases in a series of alloy compositions being designed for the immobilization of technetium in a metallic waste form. The dominant metals in the alloy compositions were Fe-Mo and Fe-Mo-Zr. The alloy composition, Fe-Mo-Zr, also contained Pd, Zr, Cr, and Ni. Both non-radioactive rhenium-containing and radioactive technetium-bearing alloy compositions were investigated. In the Fe-Mo series, the phases observed were Fe2Mo (C14 Laves phase) and ferrite in agreement with predictions. Both Tc and Re resided predominantly in the Laves phases. In the Fe-Mo-Zr system, the phases included hexagonal C14 with the composition (Fe,Cr)2Mo, cubic C15 phase with a (Fe,Ni)2Zr composition, and the hcp phase Pd2Zr. The observation of these phases was in agreement with predictions. Re was found in the C14 intermetallic, (Fe,Cr)2Mo. Technetium was also observed to be partitioned preferentially into the (Fe,Cr)2Mo phase; however, this phase exhibited a cubic structure consistent with the C15 structural type. The composition of Laves phases is influenced by both the atomic size and electro-negativity of the constituent elements. The long-term release behavior of technetium under nuclear waste disposal conditions may be more dependent on the corrosion characteristics of these individual Laves phases containing Tc than the other metallic phases.

Amphibian declines have been linked to numerous factors, including pesticide use and the fungal pathogen Batrachochytrium dendrobatidis (Bd). Moreover, research has suggested a link between amphibian sensitivity to Bd and pesticide exposure. We simultaneously exposed postmetamorphic American toads (Anaxyrus americanus), western toads (A. boreas), spring peepers (Pseudacris crucifer), Pacific treefrogs (P. regilla), leopard frogs (Lithobates pipiens), and Cascades frogs (Rana cascadae) to a factorial combination of two pathogen treatments (Bd+, Bd–) and four pesticide treatments (control, ethanol vehicle, herbicide mixture, and insecticide mixture) for 14 d to quantify survival and infection load. We found no interactive effects of pesticides and Bd on anuran survival and no effects of pesticides on infection load. Mortality following Bd exposure increased in spring peepers and American toads and was dependent upon snout–vent length in western toads, American toads, and Pacific treefrogs. Previous studies ...

Stem cell research has been a popular topic in the past few decades. This review aims to discuss factors that help regulate, induce, and enhance mesenchymal stem cell (MSC) differentiation into osteoblasts for bone regeneration. The factors analyzed include bone morphogenic protein (BMP), transforming growth factor β (TGF‐β), stromal cell‐derived factor 1 (SDF‐1), insulin‐like growth factor type 1 (IGF‐1), histone demethylase JMJD3, cyclin dependent kinase 1 (CDK1), fucoidan, Runx2 transcription factor, and TAZ transcriptional coactivator. Methods promoting bone healing are also evaluated in this review that have shown promise in previous studies. Methods tested using animal models include low intensity pulsed ultrasound (LIPUS) with MSC, micro motion, AMD3100 injections, BMP delivery, MSC transplantation, tissue engineering utilizing scaffolds, anti‐IL‐20 monoclonal antibody, low dose photodynamic therapy, and bone marrow stromal cell transplants. Human clinical trial methods analyzed include osteoblast injections, bone marrow grafts, bone marrow and platelet rich plasma transplantation, tissue engineering using scaffolds, and recombinant human BMP‐2. These methods have been shown to promote and accelerate new bone formation. These various methods for enhanced bone regeneration have the potential to be used, following further research, in clinical practice.

The Weapon Sonar Test Facility (WSTF) at NUWC Keyport, WA is a 34,500 gallon pressure tank currently used for test and evaluation of torpedo sonar arrays. The tank has many more possible uses and complete characterization of the testing environment needs to be performed. One of the methods of characterization being used is the determination of the reverberation time of the anechoic chamber. Applying Sabine-Franklin-Jaeger theory of reverberant rooms, an experimentally determined reverberation time T60 for a “live room” can be used to provide an upper bound for the reverberation time in the chamber. Utilizing the Eyring theory of “dead” rooms will provide a better determination of T60 for the anechoic chamber; hence provide a lower bound characterization. The experimental method involves determining the spatially averaged acoustic energy of an initial tone and the corresponding reflection from the chamber wall seen in a recorded signal. These values determined from the root mean square signal voltage determine the wave decay time, τ. The decay time is directly related to the reverberation time through T60 = 6τ · loge 10. The reverberation was determined to be within an acceptable tolerance for testing and evaluation.

Short-term 48, 72 and 96-h aquatic toxicity tests were conducted to evaluate the acute toxicity of eight fluorinated acids to the cladoceran, Daphnia magna, the green alga, Pseudokirchneriella subcapitata, and the rainbow trout, Oncorhynchus mykiss or the fathead minnow, Pimephales promelas. The eight fluorinated acids studied were tridecafluorohexyl ethanoic acid (6:2 FTCA), heptadecafluorooctyl ethanoic acid (8:2 FTCA), 2H-dodecafluoro-2-octenoic acid (6:2 FTUCA), 2H-hexadecafluoro-2-decenoic acid (8:2 FTUCA), 2H,2H,3H,3H-undecafluoro octanoic acid (5:3 acid), 2H,2H,3H,3H-pentadecafluoro decanoic acid (7:3 acid), n-perfluoropentanoic acid (PFPeA) and n-perfluorodecanoic acid (PFDA). The results of the acute toxicity tests conducted during this study suggest that the polyfluorinated acids, 8:2 FTCA, 8:2 FTUCA, 6:2 FTCA, 6:2 FTUCA, 7:3 acid and 5:3 acid, and the perfluorinated acids PFPeA and PFDA, are generally of low to medium concern based on evaluation of their acute freshwater toxicity (EC/LC50s typically between 1 and >100 mg L(-1)) using the USEPA TSCA aquatic toxicity evaluation paradigm. For the polyfluorinated acids, aquatic toxicity generally decreased as the number of fluorinated carbons decreased and as the overall carbon chain length decreased from 12 to 8. Acute aquatic toxicity of the 5 and 10 carbon perfluorocarboxylic acids (EC/LC50s between 10.6 and >100 mg L(-1)) was greater or similar to that of the 6-9 carbon perfluorocarboxylic acids (EC/LC50s>96.5 mg L(-1)). This study also provides the first report of the acute aquatic toxicity of the 5:3 acid (EC/LC50s of 22.5 to >103 mg L(-1)) which demonstrated less aquatic toxicity than the 7:3 acid (EC/LC50s of 0.4-32 mg L(-1)). The cladoceran, D. magna and the green alga, P. subcapitata had generally similar EC50 values for a given substance while fish were typically equally or less sensitive with the exception that PFPeA was most toxic to fish. Predicted no-effect concentrations (PNECs) were estimated using approaches consistent with REACH guidance and when compared with available environmental concentrations, these PNECs suggest that the fluorinated acids tested pose little risk for aquatic organisms.

Although abnormal sexual behavior, including boar-to-boar mounting with anal penetration, is recognized in pubescent pigs, reports of the pathologic consequences are scarce. A 7-month-old male minipig, housed with age-matched males, died within 1 day of the onset of lethargy and reluctance to rise. At necropsy, 2 rectal tears were identified as the cause for fibrinous peritonitis, and spermatozoa were identified in the pelvic and peritoneal cavity by light and transmission electron microscopy. According to DNA typing results, using 11 porcine microsatellites, the intraperitoneal semen was from at least 2 pen mates. The prohibition of castration of fattening pigs, implemented or planned in multiple European countries, could increase the risk of rectal perforation in co-housed pigs.

This study measured reductive solubilization of plutonium(IV) hydrous oxide (Pu(IV)O2·xH2O(am)) with hydrogen (H2) as electron donor, in the presence or absence of dissimilatory metal-reducing bacteria (DMRB), anthraquinone-2,6-disulfonate (AQDS), and ethylenediaminetetraacetate (EDTA). In PIPES buffer at pH 7 with excess H2, Shewanella oneidensis and Geobacter sulfurreducens both solubilized

The toxicity of tridecafluorohexylethyl methacrylate (6:2 FTMAC), an acrylic monomer used in producing polymeric substances, was evaluated. 6:2 FTMAC has low acute oral and dermal toxicity (LD50>5000 mg/kg), was not a skin or eye irritant, and did not demonstrate skin sensitization potential in a local lymph node assay (LLNA). 6:2 FTMAC was not mutagenic in the bacterial reverse mutation (Ames) test or in the mouse lymphoma assay. 6:2 FTMAC induced structural aberrations in human peripheral blood lymphocytes in vitro in the absence of metabolic activation but not in the presence of S9 metabolic activation. No numerical aberrations were detected under any testing condition. Also, no increase occurred in structural or numerical chromosomal aberrations in an in vivo mouse micronucleus assay in 6:2 FTMAC treated animals compared to controls. 6:2 FTMAC was administered at 0, 100, 500 and 1000 mg/kg/day via gavage to male and female SD rats for 14 days. No test substance-related effects on mortality, clinical signs, body weights, nutritional parameters, or clinical pathology were observed at any dose. Test substance-related increases in liver weights in males and females at all dose levels and thyroid and kidney weights in 500 and 1000 mg/kg/day males were noted. While there was no histopathological correlate for thyroid and kidney weight changes, minimal hypertrophy was noted in liver in males and females at 1000 mg/kg/day group. The changes noted in teeth (altered mineralization; retention of basophilic material) and femur (increased mineralization) in all treated groups were not associated with clinical signs or microscopic changes and were likely related to free fluoride formed from 6:2 FTMAC metabolism. Plasma (3-4-fold) and urine (30-50-fold) fluoride was higher in treated groups versus controls. Therefore, the changes noted in organ weights, teeth, femur, plasma or urine were not considered adverse. In the repeated dose toxicity study, the no-observed-adverse-effect-level (NOAEL) was 1000 mg/kg/day. Based on mean measured concentrations, the 96-h LC50 in fathead minnow was >14.5 mg/L and the 72-h EC50 in Pseudokirchneriella subcapitata was >24.6 mg/L, while the 48-h EC50 in Daphnia magna, based on nominal concentrations, was >120 mg/L. Overall, 6:2 FTMAC is considered to have low toxicity potential based on these studies.

We examined whether Black Americans and Hispanic Americans experienced greater mental health benefits from religious involvement than White Americans, and whether these benefits would be mediated through three psychosocial factors--social support, meaning, and forgiveness.Utilizing data from a probability sample of Chicago-based adults (n=3103), ethnicity-stratified multivariate regression models estimated the association of religiosity with depressive symptoms, anxiety symptoms, and major depressive disorder (MDD). Models controlled for potential confounders and psychosocial mediators.Contrary to our hypotheses, religiously involved Black Americans and Hispanic Americans did not experience greater mental health benefits than their White counterparts. For White Americans alone, service attendance was inversely related to depressive symptoms, anxiety symptoms, and MDD. Religious saliency was consistently associated with worse mental health for Hispanic Americans only. However, both meaning and forgiveness conferred mental health benefits for all three groups.The benefits of specific aspects of religious involvement vary across ethnicity. Caution is necessary in any effort to bring religion into the health domain. Our findings, if replicated, suggest that initiatives that facilitate a sense of purpose or forgiveness are likely to prove promising in improving mental health, regardless of race or ethnicity.

ZusammenfassungBei einer weiblichen Thüringerwald Ziege wurden eine generalisierte Osteopenie, Zwergwuchs, Anämie und ein Kupfermangel beobachtet. Das Tier stammte aus einer Hobbyhaltung mit etwa 30 klinisch unauffälligen weiteren Ziegen. Mittels röntgenologischer sowie computertomographischer und pathomorphologischer Untersuchung konnten eine verminderte Knochendichte und zahlreiche Frakturen mit fehlender oder lediglich geringgradiger Tendenz zur Kallusbildung nachgewiesen werden. Die Veraschung ausgewählter Knochen ergab im Vergleich zu zwei Kontrolltieren keinen Unterschied hinsichtlich des Kalzium- und Phosophorgehalts, was auf eine reguläre Mineralisierung der Knochenmatrix hindeutet. Vermutet wurde eine kupfermangelbedingte Osteogenesestörung.

SUMMARY 1. Anthropogenic effects have propelled us into what many have described as the sixth mass extinction, and amphibians are among the most affected groups. The causes of global amphibian population declines and extinctions are varied, complex and context-dependent and may involve multiple stressors. However, experimental studies examining multiple factors contributing to amphibian population declines are rare. 2. Using outdoor mesocosms containing zooplankton, phytoplankton, periphyton and tadpoles, we conducted a 2 · 2 · 3 factorial experiment that examined the separate and combined effects of an insecticide and the fungal pathogen Batrachochytrium dendrobatidis (Bd) on three different assemblages of larval pacific treefrogs (Pseudacris regilla) and Cascades frogs (Rana cascadae). 3. Larval amphibian growth and development were affected by carbaryl and the amphibian assemblage treatment, but only minimally by Bd. Carbaryl delayed metamorphosis in both amphibian species and increased the growth rate of P. regilla. Carbaryl also reduced cladoceran abundance, which, in turn, had positive effects on phytoplankton abundance but no effect on periphyton biomass. Substituting 20 intraspecific competitors with 20 interspecific competitors decreased the larval period but not the growth rate of P. regilla. In contrast, substituting 20 intraspecific competitors with 20 interspecific competitors had no effect on R. cascadae. Results of real-time quantitative polymerase chain reaction (qPCR) analysis confirmed infection of Bd-exposed animals, but exposure to Bd had no effects on either species in univariate analyses, although it had significant or nearly significant effects in several multivariate analyses. In short, we found no interactive effects among the treatments on amphibian growth and development. 4. We encourage future research on the interactive effects of pesticides and pathogens on amphibian communities.

Batrachochytrium dendrobatidis (hereafter Batrachochytrium), a fungal pathogen of amphibians, causes the disease chytridiomycosis which is responsible for unprecedented population declines and extinctions globally. Host defenses against chytridiomycosis include cutaneous symbiotic bacteria and anti-microbial peptides, and proposed treatment measures include use of fungicides and bioaugmentation. Efforts to eradicate the fungus from localized areas of disease outbreak have not been successful. Instead, control measures to mitigate the impacts of the disease on host populations, many of which are already persisting with Batrachochytrium in an endemic state, may be more realistic. The infective stage of the fungus is an aquatic zoospore, 3–5 μm in diameter. Here we show that zoospores of Batrachochytrium are consumed by the zooplankter Daphnia magna. This species inhabits amphibian breeding sites where Batrachochytrium transmission occurs, and consumption of Batrachochytrium zoospores may lead to effective biological control of Batrachochytrium.

Mesoscale ocean altimetry remains a challenge in satellite remote sensing. Conventional nadir-looking radar altimeters can make observations only along the satellite ground track, and many of them are needed to sample the sea surface at the required spatial and temporal resolutions. The Passive Reflectometry and Interferometry System (PARIS) using Global Navigation Satellite Systems (GNSS) reflected signals was proposed as a means to perform ocean altimetry along several tracks simultaneously spread over a wide swath. The bandwidth limitation of the GNSS signals and the large ionospheric delay at L-band are however issues which deserve careful attention in the design and performance of a PARIS ocean altimeter. This paper describes such an instrument specially conceived to fully exploit the GNSS signals for best altimetric performance and to provide multifrequency observations to correct for the ionospheric delay. Furthermore, an in-orbit demonstration mission that would prove the expected altimetric accuracy suited for mesoscale ocean science is proposed.

Heterogeneous reduction of actinides in higher, more soluble oxidation states to lower, more insoluble oxidation states by reductants such as Fe(II) has been the subject of intensive study for more than two decades. However, Fe(II)-induced reduction of sparingly soluble Pu(IV) to the more soluble lower oxidation state Pu(III) has been much less studied, even though such reactions can potentially increase the mobility of Pu in the subsurface. Thermodynamic calculations are presented that show how differences in the free energy of various possible solid-phase Fe(III) reaction products can greatly influence aqueous Pu(III) concentrations resulting from reduction of PuO2(am) by Fe(II). We present the first experimental evidence that reduction of PuO2(am) to Pu(III) by Fe(II) was enhanced when the Fe(III) mineral goethite was spiked into the reaction. The effect of goethite on reduction of Pu(IV) was demonstrated by measuring the time dependence of total aqueous Pu concentration, its oxidation state, and syste...