A study of air-to-ground sound propagation using an instrumented meteorological tower

The results of an exploratory NASA study, leading to a better understanding of the effects of meteorological conditions on the propagation of aircraft noise, are reported. The experimental program utilized a known sound source fixed atop an instrumented meteorological tower. The basic experimental scheme consisted of measuring the amplitude of sound radiated toward the ground along a line of microphones fixed to a tower guy wire. Experimental results show the feasibility of this approach in the acquisition of data indicating the variations encountered in the time-averaged and instantaneous amplitudes of propagated sound. The investigation included a consideration of ground reflections, a comparison of measured attenuations with predicted atmospheric absorption losses, and an evaluation of the amplitude fluctuations of recorded sound pressures

A non-invasive method for measuring preimplantation embryo physiology

Author Posting. © Cambridge University Press, 2000. This article is posted here by permission of Cambridge University Press for personal use, not for redistribution. The definitive version was published in Zygote 8 (2000): 15-24, doi:10.1017/S0967199400000782.The physiology of the early embryo may be indicative of embryo vitality and therefore methods for non-invasively monitoring physiological parameters from embryos could improve preimplantation diagnoses. The self-referencing electrophysiological technique is capable of non-invasive measurement of the physiology of individual cells by monitoring the movement of ions and molecules between the cell and the surrounding media. Here we use this technique to monitor gradients of calcium, potassium, oxygen and hydrogen peroxide around individual mouse preimplantation embryos. The calcium-sensitive electrode in self-referencing mode identified a region of elevated calcium concentration ([similar]0.25 pmol) surrounding each embryo. The calcium gradient surrounding embryos was relatively steep, such that the region of elevated calcium extended into the medium only 4 [mu]m from the embryo. By contrast, using an oxygen-sensitive electrode an extensive gradient of reduced dissolved oxygen concentration was measured surrounding the embryo and extended tens of micrometres into the medium. A gradient of neither potassium nor hydrogen peroxide was observed around unperturbed embryos. We also demonstrate that monitoring the physiology of embryos using the self-referencing technique does not compromise their subsequent development. Blastocysts studied with the self-referencing technique implanted and developed to term at the same frequency as did unexamined, control embryos. Therefore, the self-referencing electrode provides a valuable non-invasive technique for studying the physiology and pathophysiology of individual embryos without hindering their subsequent development.A portion of this work was funded by an NIH R21 #RR 12718–02 to D.L.K. and P.J.S.S., KO81099 to D.L.K. and NIH P41 RR01395 to P.J.S.S

Relationships between Morning and Afternoon WUT (Weight, Urine Color, and Thirst) Criteria and Hydration Markers

A Venn diagram decision tool consisting of weight, urine color, and thirst (WUT) is suggested to measure hydration status. The WUT Venn diagram has been used as a practical hydration status assessment tool; however, this relationship has only been investigated using a first-morning urine sample. PURPOSE: To investigate relationships between morning and afternoon WUT criteria, blood and urine markers. METHODS: Eight men (age: 21 ± 3; mass: 76.3 ± 15.6 kg) and five women (age: 22 ± 2; mass: 60.5 ± 13.6 kg) completed the study. Body mass, urine color, urine specific gravity (USG), urine osmolality (UOSM), thirst level, and plasma osmolality (POSM) were collected as a first-morning and afternoon spot urine (2:00-4:00 CST) for 3 consecutive days in a free-living situation and 3 consecutive days in a euhydrated state. Body mass loss \u3e1%, urine color \u3e5, and thirst level ≥5 were used as dehydration thresholds. The number of markers that indicated dehydration levels were counted and categorized into either 3, 2, 1, or 0 WUT markers indicating dehydration (defined by either USG, UOSM, or POSM). One-way ANOVA with Tukey pairwise comparisons were used to assess differences in USG, UOSM, and POSM between different numbers of WUT markers. Receiver operating characteristics analysis was performed to calculate the predictive value of 0, 1, 2, or 3 hydration markers in detecting a dehydrated or euhydrated state. RESULTS: Morning and afternoon 1, 2, and 3 WUT markers were not significantly different (ps \u3e .05) for USG and POSM. Morning and afternoon 0, 2, and 3 WUT markers were not significantly different for UOSM. Morning and afternoon 3 WUT resulted in a specificity of 0.984 and 1.000, 0.984 and 1.000, and 0.956 and 0.981 for USG \u3e 1.020, UOSM \u3e 700mOsm, and POSM \u3e 290mOsm, respectively. Meeting at 2 WUT for morning and afternoon resulted in a specificity of 0.820 and 0.985, and 0.806 and 0.984 for USG and UOSM, respectively. Meeting at 1 WUT for morning and afternoon resulted in a sensitivity of 1.000 and 0.813 for UOSM. CONCLUSION: These results suggest that when 2 or 3 WUT markers are met, urine and blood hydration markers indicate dehydration, and when 1 WUT marker is met, UOSM indicates not dehydrated. The WUT Venn diagram can assess hydration status when an afternoon spot urine sample is used

Disordered Regimes of the one-dimensional complex Ginzburg-Landau equation

I review recent work on the ``phase diagram'' of the one-dimensional complex Ginzburg-Landau equation for system sizes at which chaos is extensive. Particular attention is paid to a detailed description of the spatiotemporally disordered regimes encountered. The nature of the transition lines separating these phases is discussed, and preliminary results are presented which aim at evaluating the phase diagram in the infinite-size, infinite-time, thermodynamic limit.Comment: 14 pages, LaTeX, 9 figures available by anonymous ftp to amoco.saclay.cea.fr in directory pub/chate, or by requesting them to [email protected]

Evaluational adjectives

This paper demarcates a theoretically interesting class of "evaluational adjectives." This class includes predicates expressing various kinds of normative and epistemic evaluation, such as predicates of personal taste, aesthetic adjectives, moral adjectives, and epistemic adjectives, among others. Evaluational adjectives are distinguished, empirically, in exhibiting phenomena such as discourse-oriented use, felicitous embedding under the attitude verb `find', and sorites-susceptibility in the comparative form. A unified degree-based semantics is developed: What distinguishes evaluational adjectives, semantically, is that they denote context-dependent measure functions ("evaluational perspectives")—context-dependent mappings to degrees of taste, beauty, probability, etc., depending on the adjective. This perspective-sensitivity characterizing the class of evaluational adjectives cannot be assimilated to vagueness, sensitivity to an experiencer argument, or multidimensionality; and it cannot be demarcated in terms of pretheoretic notions of subjectivity, common in the literature. I propose that certain diagnostics for "subjective" expressions be analyzed instead in terms of a precisely specified kind of discourse-oriented use of context-sensitive language. I close by applying the account to `find x PRED' ascriptions

Sleep Duration is Increased Following Muscle Damaging Exercise in Hot Environmental Conditions

Sleep and recovery measures are typically negatively affected by a muscle-damaging bout of exercise. However, it remains unknown if the additive effects of hot environmental conditions, resulting in increased core temperature and other thermoregulatory responses during the exercise bout, further progress changes in quantity and performance quality of sleep duration. PURPOSE: To investigate the effect of muscle-damaging exercise in the heat, compared to a thermoneutral condition, on sleep and recovery measures. METHODS: Ten healthy males (age: 23 ± 3yr; body mass: 78.7 ± 11.5kg; height: 176.9 ± 5cm; lactate threshold [LT]: 9.7 ± 1.0km.hr-1) performed two protocols in a randomized, counterbalanced order of downhill running (DHR) for 30-minutes at the LT in either a thermoneutral (ambient temperate [Tamb], 20°C; relative humidity [RH], 20%) or hot environmental condition (Tamb, 35°C; RH, 40%) at a -10% gradient. Sleep and recovery measures were collected from a wearable sleep device participants wore the night after the DHR. Differences in sleep and recovery measures following DHR in the heat compared to a thermoneutral condition were analyzed using paired samples T-tests. RESULTS: Sleep hours, restorative sleep hours, rapid eye movement (REM) sleep hours, and slow wave sleep (SWS) hours were all greater following the heat condition (mean ± SD; sleep hours: 6.70 ± 0.74hr, p = 0.040; restorative sleep hours: 3.31 ± 0.90hr, p = 0.012; REM sleep hours: 1.70 ± 0.64hr, p = 0.046; SWS hours: 1.61 ± 0.35hr, p = 0.015) compared to the thermoneutral condition (sleep hours: 5.24 ± 1.75hr; restorative sleep hours: 2.45 ± 1.11hr; REM sleep hours: 1.23 ± 0.68hr; SWS: 1.22 ± 0.53hr). Also, recovery was higher following the heat condition (recovery: 75.88 ± 15.31, p = 0.023) compared to the thermoneutral condition (recovery: 50.75 ± 21.46). Sleep efficiency, sleep disturbance, sleep deprivation, sleep score, %REM, %SWS, light sleep, resting heart rate, and heart rate variability were not different between conditions (ps \u3e 0.05). CONCLUSION: Following muscle-damaging exercise in the heat, sleep and recovery duration measures were increased compared to a thermoneutral condition. These findings suggest that performing muscle-damaging exercises in hot conditions may require a greater amount of sleep for optimal recovery