Voyager radio occultation investigations at Saturn

Voyager will use dual-frequency 3.5 and 13 cm wavelength radio occultation techniques to study the atmospheres and ionospheres of Saturn and Titan, and the rings of Saturn. At Titan radio occultation is predicted to probe the atmosphere to the surface. The existence of a surface could be confirmed by detection of an obliquely scattered echo. At Saturn the two Voyager encounters will provide occultation measurements of temperate and equatorial regions of the atmosphere and ionosphere, and of the rings. The atmosphere will also be probed in polar regions during the deepest portions of the occultation. Both frequency and intensity data will be collected and jointly analyzed to study temperature-pressure profiles, and to derive information on atmospheric shape, turbulence, and weather. For the rings, Voyager will provide measurements of the complex (amplitude and phase) radio extinction and angular scattering functions of the ring particles as a function of wavelength, polarization, and radial distance from Saturn

Efficacy and Residue Comparisons between Two Slow-release Formulations of Fluridone

Residue profiles and efficacy of Avast and Sonar, two slow release pellet formulations of fluridone {1-methyl-3-phenyl-5- [3-(trifluoromethyl)phenly]-4(1H)-pyridinone}, were compared in outdoor tanks. Hydrilla (Hydrilla verticillata (L.f.) Royle) and southern naiad (Najas guadalupensis (Sprengel) Magnus) were treated with a split application of 6, 12, 18 and 24 μg/l a.i. fluridone and the concentrations of both formulations compared over a 134-day period. Both pellet formulations exhibited very similar residues over time for each respective treatment, resulted in peak concentrations of fluridone 40 to 50 days after application, and effectively and similarly controlled southern naiad and hydrilla at all rates tested by 92 days after initial application. (PDF contains 3 pages.

Estimation of inertial platform errors

Equations for inertial platform error mode

On the maximum bias functions of MM-estimates and constrained M-estimates of regression

We derive the maximum bias functions of the MM-estimates and the constrained M-estimates or CM-estimates of regression and compare them to the maximum bias functions of the S-estimates and the $\tau$-estimates of regression. In these comparisons, the CM-estimates tend to exhibit the most favorable bias-robustness properties. Also, under the Gaussian model, it is shown how one can construct a CM-estimate which has a smaller maximum bias function than a given S-estimate, that is, the resulting CM-estimate dominates the S-estimate in terms of maxbias and, at the same time, is considerably more efficient.Comment: Published at http://dx.doi.org/10.1214/009053606000000975 in the Annals of Statistics (http://www.imstat.org/aos/) by the Institute of Mathematical Statistics (http://www.imstat.org

The consequences of feminization in breeding groups of wild fish

EHP is a publication of the U.S. government. Publication of EHP lies in the public domain and is therefore without copyright. Research articles from EHP may be used freely; however, articles from the News section of EHP may contain photographs or figures copyrighted by other commercial organizations and individuals that may not be used without obtaining prior approval from both the EHP editors and the holder of the copyright. Use of any materials published in EHP should be acknowledged (for example, "Reproduced with permission from Environmental Health Perspectives") and a reference provided for the article from which the material was reproduced.BACKGROUND: The feminization of nature by endocrine-disrupting chemicals (EDCs) is a key environmental issue affecting both terrestrial and aquatic wildlife. A crucial and as yet unanswered question is whether EDCs have adverse impacts on the sustainability of wildlife populations. There is widespread concern that intersex fish are reproductively compromised, with potential population-level consequences. However, to date, only in vitro sperm quality data are available in support of this hypothesis. OBJECTIVE: The aim of this study was to examine whether wild endocrine-disrupted fish can compete successfully in a realistic breeding scenario. METHODS: In two competitive breeding experiments using wild roach (Rutilus rutilus), we used DNA microsatellites to assign parentage and thus determine reproductive success of the adults. RESULTS: In both studies, the majority of intersex fish were able to breed, albeit with varying degrees of success. In the first study, where most intersex fish were only mildly feminized, body length was the only factor correlated with reproductive success. In the second study, which included a higher number of more severely intersex fish, reproductive performance was negatively correlated with severity of intersex. The intersex condition reduced reproductive performance by up to 76% for the most feminized individuals in this study, demonstrating a significant adverse effect of intersex on reproductive performance. CONCLUSION: Feminization of male fish is likely to be an important determinant of reproductive performance in rivers where there is a high prevalence of moderately to severely feminized males.Funding for this work was derived through the Endocrine Disruption in Catchments project, which was supported by the U.K. Department for Environment Food and Rural Affairs and the U.K. Environment Agency

Hand Cooling during Recovery from Exercise in the Heat: Cold Water Immersion vs. Dry Cold Negative Pressure

Areas of the body that are devoid of hair, such as the palms of our hands, efficiently dissipate heat through specialized blood vessels. Immersing the hands in cold water is said to benefit the process of heat exchange, but has been criticized for its ability induce cutaneous vasoconstriction. The use of dry cold negative pressure is proposed to bypass this reflex in order to increase constant heat dissipation. PURPOSE: To compare the effect of two different hand cooling modalities on core temperature when recovering from exercise in a hot environment. METHODS: Males (N=12, 21±2 yr, 64±15 kg, 174±6 cm) of average cardiorespiratory fitness (VO2Peak=37+3 ml.kg-1.min-1) participated in three heat trials (35.1±0.2°C, 42±1%RH,) where they exercised on a cycle ergometer at 65% VO2Peak until a desired core temperature (38.3°C), 95% of heart rate max, or until volitional maximum. During recovery from the heat trials, subjects underwent one of three hand cooling treatments for 10 min [cold water immersion (WTR), dry cold negative pressure (NEG), and a control with no hand cooling (CON)] in a balanced crossover design. In WTR trials subjects submerged one hand in cold (10°C) water, and in NEG the hand was placed in sealed cold (10°C) container (AVAcore CoreControl Pro) that provided negative pressure (-47 mm Hg). Heart rate (HR) and core temperature (rectal, Tre) were measured pre-/post-recovery cooling. Two way (cooling method x time) repeated measures ANOVA was used to analyze recovery HR and Tre (α=0.05). RESULTS: The main effect for cooling method was not significant for both HR (WTR=117±12 bpm, NEG=113±9 bpm, CON=118±13 bpm)(p=0.1650) and Tre (WTR=37.7±0.3°C, NEG=37.8±0.2°C, CON=37.8±0.3°C)(p=0.3560) during recovery. As expected, the main effect for time was significant for both Tre (Pre=37.8±0.2°C, Post=37.6±0.2°C)(p=0.0040) and HR (Pre=135±13 bpm, Post=97±9 bpm)(p=0.0001) as both declined during recovery. The cooling method x time interaction (p=0.4280) did not demonstrate that Tre decreased differently between the three cooling modalities, but the cooling method x time interaction for HR was significant (p=0.0320) where the change in HR during recovery periods did differ significantly between the cooling modalities. The significant interaction was driven by the WTR treatment HR declining at a slightly quicker rate than NEG and CON. CONCLUSION: The use of WTR or NEG didn’t decrease Tre any more efficiently than CON, but recovery HR did decline at slightly greater rate in WTR compared to both NEG and CON. This could suggest that while WTR provided a similar Tre reduction as NEG and CON, it did so with a quicker reduction in heart work