Superfluid Optomechanics: Coupling of a Superfluid to a Superconducting Condensate

We investigate the low loss acoustic motion of superfluid $^4$He parametrically coupled to a very low loss, superconducting Nb, TE$_{011}$ microwave resonator, forming a gram-scale, sideband resolved, optomechanical system. We demonstrate the detection of a series of acoustic modes with quality factors as high as $7\cdot 10^6$. At higher temperatures, the lowest dissipation modes are limited by an intrinsic three phonon process. Acoustic quality factors approaching $10^{11}$ may be possible in isotopically purified samples at temperatures below 10 mK. A system of this type may be utilized to study macroscopic quantized motion and as an ultra-sensitive sensor of extremely weak displacements and forces, such as continuous gravity wave sources

Sensor/Actuator Selection for the Constrained Variance Control Problem

The problem of designing a linear controller for systems subject to inequality variance constraints is considered. A quadratic penalty function approach is used to yield a linear controller. Both the weights in the quadratic penalty function and the locations of sensors and actuators are selected by successive approximations to obtain an optimal design which satisfies the input/output variance constraints. The method is applied to NASA's 64 meter Hoop-Column Space Antenna for satellite communications. In addition the solution for the control law, the main feature of these results is the systematic determination of actuator design requirements which allow the given input/output performance constraints to be satisfied

Ultra-high Q Acoustic Resonance in Superfluid 4He

We report the measurement of the acoustic quality factor of a gram-scale, kilo-hertz frequency superfluid resonator, detected through the parametric coupling to a superconducting niobium microwave cavity. For temperature between 400mK and 50mK, we observe a $T^{-4}$ temperature dependence of the quality factor, consistent with a 3-phonon dissipation mechanism. We observe Q factors up to $1.4\cdot10^8$, consistent with the dissipation due to dilute $^3$He impurities, and expect that significant further improvements are possible. These experiments are relevant to exploring quantum behavior and decoherence of massive macroscopic objects, the laboratory detection of continuous wave gravitational waves from pulsars, and the probing of possible limits to physical length scales.Comment: 5 pages, 2 figure

THE EFFECTS OF ALTERNATE COW FRESHENING DISTRIBUTIONS ON MILK PRODUCTION AND IMPORTS IN FLORIDA

Seasonal swings in milk production in Florida result in a need to import milk on a seasonal basis. A linear programming analysis is used to analyze alternate freshening-date distributions and project the cost savings to Florida dairy farmers from reduced milk imports.Farm Management,

Lionfish (\u3ci\u3ePterois volitans\u3c/i\u3e) as biomonitoring species for oil pollution effects in coral reef ecosystems

With oil spills, and other sources of aromatic hydrocarbons, being a continuous threat to coral reef systems, and most reef fish species being protected or difficult to collect, the use of the invasive lionfish (Pterois volitans) might be a good model species to monitor biomarkers in potentially exposed fish in the Caribbean and western Atlantic. The rapid expansion of lionfish in the Caribbean and western Atlantic, and the unregulated fishing for this species, would make the lionfish a suitable candidate as biomonitoring species for oil pollution effects. However, to date little has been published about the responses of lionfish to environmental pollutants. For this study lionfish were collected in the Florida Keys a few weeks after Hurricane Irma, which sank numerous boats resulting in leaks of oil and fuel, and during the winter and early spring after that. Several biomarkers indicative of exposure to PAHs (bile fluorescence, cytochrome P450-1A induction, glutathione S-transferase activity) were measured. To establish if these biomarkers are inducible in PAH exposed lionfish, dosing experiments with different concentrations of High Energy Water Accommodated Fraction of crude oil were performed. The results revealed no significant effects in the biomarkers in the field collected fish, while the exposure experiments demonstrated that lionfish did show strong effects in the measured biomarkers, even at the lowest concentration tested (0.3% HEWAF, or 25 μg/l ƩPAH50). Based on its widespread distribution, relative ease of collection, and significant biomarker responses in the controlled dosing experiment, it is concluded that lionfish has good potential to be used as a standardized biomonitoring species for oil pollution in its neotropical realm

Distribution and potential bioeffects of atrazine in coastal waters

Estuaries provide critical nursery habitat for many commercially and recreationally important fish and shellfish species. These productive, diverse ecosystems are particularly vulnerable to pollution because they serve as repositories for non–point-source contaminants from upland sources, such as pesticide runoff. Atrazine, among the most widely used pesticides in the United States, has also been one of the most extensively studied. There has not, however, been a specific assessment of atrazine in marine and estuarine ecosystems. This document characterizes the presence and transformation of atrazine in coastal waters, and the effects of atrazine on marine organisms. Review of marine and estuarine monitoring data indicate that atrazine is chronically present in U.S. coastal waters at relatively low concentrations. The concentrations detected have typically been below acute biological effects levels, and below the U.S. EPA proposed water quality criteria for atrazine. While direct risk of atrazine impacts are low, uncertainty remains regarding the effects of long-term low levels of atrazine in mixture with other contaminants. It is recommended that best management practices, such as the use of vegetative buffers and public education about pesticide use, be encouraged in the coastal zone to minimize runoff of atrazine into marine and estuarine waters

The ocean sampling day consortium

Ocean Sampling Day was initiated by the EU-funded Micro B3 (Marine Microbial Biodiversity, Bioinformatics, Biotechnology) project to obtain a snapshot of the marine microbial biodiversity and function of the world’s oceans. It is a simultaneous global mega-sequencing campaign aiming to generate the largest standardized microbial data set in a single day. This will be achievable only through the coordinated efforts of an Ocean Sampling Day Consortium, supportive partnerships and networks between sites. This commentary outlines the establishment, function and aims of the Consortium and describes our vision for a sustainable study of marine microbial communities and their embedded functional traits

Prospective open-label study of add-on and monotherapy topiramate in civilians with chronic nonhallucinatory posttraumatic stress disorder

BACKGROUND: In order to confirm therapeutic effects of topiramate on posttraumatic stress disorder (PTSD) observed in a prior study, a new prospective, open-label study was conducted to examine acute responses in chronic, nonhallucinatory PTSD. METHODS: Thirty-three consecutive newly recruited civilian adult outpatients (mean age 46 years, 85% female) with DSM-IV-diagnosed chronic PTSD, excluding those with concurrent auditory or visual hallucinations, received topiramate either as monotherapy (n = 5) or augmentation (n = 28). The primary measure was a change in the PTSD Checklist-Civilian Version (PCL-C) score from baseline to 4 weeks, with response defined as a ≥ 30% reduction of PTSD symptoms. RESULTS: For those taking the PCL-C at both baseline and week 4 (n = 30), total symptoms declined by 49% at week 4 (paired t-test, P < 0.001) with similar subscale reductions for reexperiencing, avoidance/numbing, and hyperarousal symptoms. The response rate at week 4 was 77%. Age, sex, bipolar comorbidity, age at onset of PTSD, duration of symptoms, severity of baseline PCL-C score, and monotherapy versus add-on medication administration did not predict reduction in PTSD symptoms. Median time to full response was 9 days and median dosage was 50 mg/day. CONCLUSIONS: Promising open-label findings in a new sample converge with findings of a previous study. The use of topiramate for treatment of chronic PTSD, at least in civilians, warrants controlled clinical trials