Evaluation of noninvasive cardiac output methods during exercise

Noninvasive techniques to estimate cardiac output (Qc) will be used during future space flight. This retrospective literature survey compared the Qc techniques of carbon dioxide rebreathing (CO2-R), CO2 single breath (CO2-S), Doppler (DOP), impedance (IM), and inert gas (IG: acetylene or nitrous oxide) to direct (DIR) assessments measured at rest and during exercise

Fuel utilization during exercise after 7 days of bed rest

Energy yield from carbohydrate, fat, and protein during physical activity is partially dependent on an individual's fitness level. Prolonged exposure to microgravity causes musculoskeletal and cardiovascular deconditioning; these adaptations may alter fuel utilization during space flight. Carbohydrate and fat metabolism during exercise were analyzed before and after 7 days of horizontal bed rest

Comparison of total body water estimates from O-18 and bioelectrical response prediction equations

Identification of an indirect, rapid means to measure total body water (TBW) during space flight may aid in quantifying hydration status and assist in countermeasure development. Bioelectrical response testing and hydrostatic weighing were performed on 27 subjects who ingested O-18, a naturally occurring isotope of oxygen, to measure true TBW. TBW estimates from three bioelectrical response prediction equations and fat-free mass (FFM) were compared to TBW measured from O-18. A repeated measures MANOVA with post-hoc Dunnett's Test indicated a significant (p less than 0.05) difference between TBW estimates from two of the three bioelectrical response prediction equations and O-18. TBW estimates from FFM and the Kushner & Schoeller (1986) equation yielded results that were similar to those given by O-18. Strong correlations existed between each prediction method and O-18; however, standard errors, identified through regression analyses, were higher for the bioelectrical response prediction equations compared to those derived from FFM. These findings suggest (1) the Kushner & Schoeller (1986) equation may provide a valid measure of TBW, (2) other TBW prediction equations need to be identified that have variability similar to that of FFM, and (3) bioelectrical estimates of TBW may prove valuable in quantifying hydration status during space flight

Physiological responses to wearing the space shuttle launch and entry suit and the prototype advanced crew escape suit compared to the unsuited condition

The launch and entry suit (LES) is a life support suit worn during Orbiter ascent and descent. The impact of suit weight and restricted mobility on egress from the Orbiter during an emergency is unknown. An alternate suit - the advanced crew escape suite (ACES) - is being evaluated. The physiological responses to ambulatory exercise of six subjects wearing the LES and ACES were measured and compared to those measurements taken while unsuited. Dependent variables included heart rate and metabolic response to treadmill walking at 5.6 km/h (3.5 mph), and also bilateral concentric muscle strength about the knee, shoulder, and elbow. No significant (p greater than 0.06) differences in heart rate or metabolic variables were measured in either suit while walking at 5.6 km/h. Significant (p less than 0.05) decreases in all metabolic variables were remarked when both suits were compared to the unsuited condition. There were no significant (p greater than 0.05) differences among the three suit conditions at 30 or 180 deg/s for muscles about the elbow and knee; however, about the shoulder, a significant (p = 0.0215) difference between the ACES and the unsuited condition was noted. Therefore, wearing a life support suit while performing Orbiter egress imposes a significant metabolic demand on crewmembers. Selective upper body strength movements may be compromised

Using ³⁶Cl exposure dating to date mass movement and assess land stability on the Nicholas Range, Tasmania

Detailed mapping of dolerite slope deposits overlying sedimentary Triassic rocks on the northern slopes of the Nicholas Range in northeastern Tasmania has revealed an extensive mass movement complex. Landforms north of the summit plateau of the Nicholas Range include the following: (1) a cliff of dolerite columns with associated scree slopes at its base; (2) a topple landscape consisting of several topples that have fallen in a north-easterly direction; (3) a ripple landscape consisting of a series of long boulder ridges aligned approximately east-west. Exposure dates were obtained for three large boulders (collapsed dolerite columns) from a ridge within the ripple landscape. The two youngest dates gave a mean age of 52.1 ± 1.9 ka using36Cl. This is the estimated age for collapse of the dated columns from the cliff face c. 750 m to the south. Boulder ages and landscape morphology indicate that the ripple landscape developed by physical and chemical degradation and concurrent northern displacement of topples over a slip plane formed at the contact between dolerite colluvium and underlying Triassic sedimentary rocks. There is no evidence of movement today, other than localised debris flows associated with knickpoints in streams, and it is deduced that movement on the slip plane occurred under a cooler climate than that prevailing today, possibly under the influence of melting of winter snow during the last glacial cycle. As there is no evidence of significant recent mass movement and forests in the area are likely to have experienced many stand-destroying forest fires in the Holocene, forest harvest is not considered to pose a risk to landscape stability

Do Oil Industry Merger Waves Reveal Any Trends?

The dynamics of the stock prices of oil industry acquirer companies are studied during in-wave and out-wave years between 1998 and 2013. The research question is do oil industry merger waves reveal any trends? This quantitative study focuses on stock returns of acquirer companies over a four-year horizon for each merger transaction. Portfolios created from these transactions provide a comparison between in-wave and out-wave years. Three benchmarks are incorporated to provide various economic adjustment factors. Six cases are presented whose outcome largely follow other similar studies. The main contribution of the study is the identification of a dynamic during oil industry in-wave years which sees a substantial increase in the Brent oil market price, of at least 29% for these in-wave years. This dynamic is not identified previously in the literature. Keywords: Oil Industry Mergers, Waves, Crude Oil Price, 1998-2013 JEL Classifications: G15, G34, P1

Are Oil Industry Mergers Becoming Less Profitable?

Are oil industry mergers becoming less profitable? This study evaluates oil industry consolidations that occur during the sixteen-year time frame between 1998 and 2013 to find out. This quantitative study focuses on the stock price total return performance of acquirer companies over a four year horizon for each merger transaction. The portfolios created from these transactions provide for an analysis of the economics of the mergers after full integration of target companies. Four benchmarks are incorporated to provide various economic adjustment factors. There are seven cases presented that show that oil industry mergers are becoming less profitable. Implications are that companies may chase mergers as an easy way to increase returns, but this may not occur. As ever larger companies chase the remaining players and bid up their selling prices, increased returns may not always be the outcome. Keywords: Oil Industry Mergers, 1998-2013, Brent Crude Oil JEL Classifications: G15, G34, P1

Assessment of mood in aphasia following stroke: validation of the Dynamic Visual Analogue Mood Scales (D-VAMS)

OBJECTIVES: To validate a non-verbal self-report measure of mood - the Dynamic Visual Analogue Mood Scales (D-VAMS) - against the Hospital Anxiety and Depression Scale (HADS) and assess its suitability as an outcome measure or screening measure for depressed mood following stroke. DESIGN: Cross-sectional observational cohort study. PARTICIPANTS: Forty-six stroke survivors (24% with aphasia) recruited from online, from stroke clubs and via an NHS rehabilitation service. METHODS: A set of seven bipolar scales was developed enabling users to report mood by modifying facial expression images using a slider. Participants completed a tablet/computer task, reporting their mood on these scales mixed randomly with versions which used only words. The HADS was then completed, followed by a repeat run of the two versions in a different, random sequence. RESULTS: Exploratory factor analysis identified one factor consistent with pleasantness of mood accounting for 80% of the variance. Internal consistency of D-VAMS was high ( α = 0.95), and there was a high correlation between face-only D-VAMS scores and HADS total scores ( r = -0.80, P < 0.001), as well as HADS-D/HADS-A subscale scores ( r = -0.73, P < 0.001; r = -0.71, P < 0.001). D-VAMS showed good sensitivity and specificity against HADS, with means of 85%/77% (sensitivity/specificity) against the HADS-D and 80%/77% against the HADS-A across nine cut-offs. CONCLUSION: D-VAMS is a valid and reliable measure likely suitable for assessment of depressed mood in aphasia following stroke. Though D-VAMS performed well as a screening measure in this study sample, further study is needed in the acute stage post-stroke

Monitoring the Formation of a CH<inf>3</inf>NH<inf>3</inf>PbI<inf>3-</inf><inf>x</inf>Cl<inf>x</inf> Perovskite during Thermal Annealing Using X-Ray Scattering

Grazing incidence wide and small angle X-ray scattering (GIWAXS and GISAXS) measurements have been used to study the crystallization kinetics of the organolead halide perovskite CH3NH3PbI3-xClx during thermal annealing. In situ GIWAXS measurements recorded during annealing are used to characterize and quantify the transition from a crystalline precursor to the perovskite structure. In situ GISAXS measurements indicate an evolution of crystallite sizes during annealing, with the number of crystallites having sizes between 30 and 400 nm increasing through the annealing process. Using ex situ scanning electron microscopy, this evolution in length scales is confirmed and a concurrent increase in film surface coverage is observed, a parameter crucial for efficient solar cell performance. A series of photovoltaic devices are then fabricated in which perovskite films have been annealed for different times, and variations in device performance are explained on the basis of X-ray scattering measurements