Appetite Suppression and Altered Food Preferences Coincide with Changes in Appetite-Mediating Hormones During Energy Deficit at High Altitude, But Are Not Affected by Protein Intake

Appetite suppression and altered food preferences coincide with changes in appetite-mediating hormones during energy deficit at high altitude, but are not affected by protein intake. High Alt Med Biol. 19:156–169, 2018.—Anorexia and unintentional body weight loss are common during high altitude (HA) sojourn, but underlying mechanisms are not fully characterized, and the impact of dietary macronutrient composition on appetite regulation at HA is unknown. This study aimed to determine the effects of a hypocaloric higher protein diet on perceived appetite and food preferences during HA sojourn and to examine longitudinal changes in perceived appetite, appetite mediating hormones, and food preferences during acclimatization and weight loss at HA. Following a 21-day level (SL) period, 17 unacclimatized males ascended to and resided at HA (4300 m) for 22 days. At HA, participants were randomized to consume measured standard-protein (1.0 g protein/kg/d) or higher protein (2.0 g/kg/d) hypocaloric diets (45% carbohydrate, 30% energy restriction) and engaged in prescribed physical activity to induce an estimated 40% energy deficit. Appetite, food preferences, and appetite-mediating hormones were measured at SL and at the beginning and end of HA. Diet composition had no effect on any outcome. Relative to SL, appetite was lower during acute HA (days 0 and 1), but not different after acclimatization and weight loss (HA day 18), and food preferences indicated an increased preference for sweet- and low-protein foods during acute HA, but for high-fat foods after acclimatization and weight loss. Insulin, leptin, and cholecystokinin concentrations were elevated during acute HA, but not after acclimatization and weight loss, whereas acylated ghrelin concentrations were suppressed throughout HA. Findings suggest that appetite suppression and altered food preferences coincide with changes in appetite-mediating hormones during energy deficit at HA. Although dietary protein intake did not impact appetite, the possible incongruence with food preferences at HA warrants consideration when developing nutritional strategies for HA sojourn

Submarine gas seepage in a mixed contractional and shear deformation regime: Cases from the Hikurangi oblique-subduction margin

Gas seepage from marine sediments has implications for understanding feedbacks between the global carbon reservoir, seabed ecology and climate change. Although the relationship between hydrates, gas chimneys and seafloor seepage is well established, the nature of fluid sources and plumbing mechanisms controlling fluid escape into the hydrate zone and up to the seafloor remain one of the least understood components of fluid migration systems. In this study we present the analysis of new three-dimensional high-resolution seismic data acquired to investigate fluid migration systems sustaining active seafloor seepage at Omakere Ridge, on the Hikurangi subduction margin, New Zealand. The analysis reveals at high resolution, complex overprinting fault structures (i.e. protothrusts, normal faults from flexural extension, and shallow (<1 km) arrays of oblique shear structures) implicated in fluid migration within the gas hydrate stability zone in an area of 2x7 km. In addition to fluid migration systems sustaining seafloor seepage on both sides of a central thrust fault, the data show seismic evidence for sub-seafloor gas-rich fluid accumulation associated with proto-thrusts and extensional faults. In these latter systems fluid pressure dissipation through time has been favored, hindering the development of gas chimneys. We discuss the elements of the distinct fluid migration systems and the influence that a complex partitioning of stress may have on the evolution of fluid flow systems in active subduction margins

Surface rupture of multiple crustal faults in the 2016 Mw 7.8 Kaikōura, New Zealand, earthquake

Multiple (>20 >20 ) crustal faults ruptured to the ground surface and seafloor in the 14 November 2016 M w Mw 7.8 Kaikōura earthquake, and many have been documented in detail, providing an opportunity to understand the factors controlling multifault ruptures, including the role of the subduction interface. We present a summary of the surface ruptures, as well as previous knowledge including paleoseismic data, and use these data and a 3D geological model to calculate cumulative geological moment magnitudes (M G w MwG ) and seismic moments for comparison with those from geophysical datasets. The earthquake ruptured faults with a wide range of orientations, sense of movement, slip rates, and recurrence intervals, and crossed a tectonic domain boundary, the Hope fault. The maximum net surface displacement was ∼12  m ∼12  m on the Kekerengu and the Papatea faults, and average displacements for the major faults were 0.7–1.5 m south of the Hope fault, and 5.5–6.4 m to the north. M G w MwG using two different methods are M G w MwG 7.7 +0.3 −0.2 7.7−0.2+0.3 and the seismic moment is 33%–67% of geophysical datasets. However, these are minimum values and a best estimate M G w MwG incorporating probable larger slip at depth, a 20 km seismogenic depth, and likely listric geometry is M G w MwG 7.8±0.2 7.8±0.2 , suggests ≤32% ≤32% of the moment may be attributed to slip on the subduction interface and/or a midcrustal detachment. Likely factors contributing to multifault rupture in the Kaikōura earthquake include (1) the presence of the subduction interface, (2) physical linkages between faults, (3) rupture of geologically immature faults in the south, and (4) inherited geological structure. The estimated recurrence interval for the Kaikōura earthquake is ≥5,000–10,000  yrs ≥5,000–10,000  yrs , and so it is a relatively rare event. Nevertheless, these findings support the need for continued advances in seismic hazard modeling to ensure that they incorporate multifault ruptures that cross tectonic domain boundaries

Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570

Rates of deformation, uplift, and landscape development associated with active folding in the Waipara area of North Canterbury, New Zealand

Analysis of the geometry and ages of faulted and tilted late Quaternary fluvial terraces and their associated cover beds provide evidence of active folding at three localities in the Waipara area of North Canterbury, New Zealand. Terrace survey data, the occurrence of the approximately 22.6-kyr-old Aokautere Ash, and examination of soil profiles indicate that folding has continued into the late Holocene but that the amounts and rates of deformation are locally variable. Rates of uplift in the Waipara area are compared with those derived from marine terraces preserved at the Pacific coast, east of the study area. Results indicate that rates of measurable deformation reach a maximum along the Waipara range front, where bedrock deformation is most intense and shortening rates of up to 5.57±0.69%/100 kyr occur. Across the coastal ranges the average rate of shortening is 0.8±0.4%/100 kyr, which corresponds with an absolute shortening rate of 1.4±0.6 m/kyr and represents only a small proportion of the predicted plate motion vector in this region. Uplift rates range from 0–1.83 m/kyr for a late last glacial fluvial terrace and from 1.36–2.16 m/kyr for three marine terraces. Fluvial and marine terrace uplift rates vary in accord with the geometries of the folds in bedrock, and the spatial pattern of uplift directly reflects fold growth. The structure contour pattern of folded surfaces provides a first approximation to the spatial pattern of uplift. Differential uplift due to folding accounts for up to approximately 55–75% of the total uplift and has produced folds with structural relief of about 1300 m (i.e., amplitudes of 600–700 m). These folds have formed over the last 0.8±0.4 m.y. since the onset of Quaternary deformation in the Waipara region

Comparison of autoregressive and multitaper spectral analysis for long time series

The periodogram (i.e., the square of the Fourier transform) of a time series generally provides a poor estimate of the spectrum if that spectrum has a wide dynamic range. So the spectrum of any process that includes either one or many resonant modes (sharp peaks) can be expected to be poorly computed by such elementary means. Multitaper spectral analysis is a nonparametric method designed to provide a rigorous method of resolving the spectrum of such complex processes. There are some practical difficulties with this method, such as deciding what tapers to use and how many, that can make the method some what difficult for the uninitiated user. Another approach to spectral analysis is the parametric method known as autoregressive (AR) analysis (related but not identical to maximum entropy spectral analysis). AR analysis can be used to approximate the dominant modes in the spectrum, remove them from the time series and thus prewhiten the remaining time series, thereby eliminating the main problem with analysis based on the periodogram. Furthermore, if the main purpose of the spectral analysis is to determine the number and location of the modes, the AR method provides a set of parameters that can be used to describe the mode structure if desired. The present paper provides a set of examples comparing the use of both the multitaper method and the autoregressive method for analyzing the same (long) time series data. We find that both methods give very comparable results in these examples, thus providing a type of empirical cross-validation showing that both methods are therefore doing an excellent job of estimating the true spectrum of the time series

Effects of testosterone supplementation on body composition and lower-body muscle function during severe exercise- and diet-induced energy deficit: A proof-of-concept, single centre, randomised, double-blind, controlled trial

BACKGROUND: Severe energy deficits during military operations, produced by significant increases in exercise and limited dietary intake, result in conditions that degrade lean body mass and lower-body muscle function, which may be mediated by concomitant reductions in circulating testosterone. METHODS: We conducted a three-phase, proof-of-concept, single centre, randomised, double-blind, placebo-controlled trial (CinicalTrials.gov, NCT02734238) of non-obese men: 14-d run-in, free-living, eucaloric diet phase; 28-d live-in, 55% exercise- and diet-induced energy deficit phase with (200 mg testosterone enanthate per week, Testosterone, n = 24) or without (Placebo, n = 26) exogenous testosterone; and 14-d recovery, free-living, ad libitum diet phase. Body composition was the primary end point; secondary endpoints included lower-body muscle function and health-related biomarkers. FINDINGS: Following energy deficit, lean body mass increased in Testosterone and remained stable in Placebo, such that lean body mass significantly differed between groups [mean difference between groups (95% CI), 2.5 kg (3.3, 1.6); P \u3c .0001]. Fat mass decreased similarly in both treatment groups [0.2 (-0.4, 0.7), P = 1]. Change in lean body mass was associated with change in total testosterone (r = 0.71, P \u3c .0001). Supplemental testosterone had no effect on lower-body muscle function or health-related biomarkers. INTERPRETATION: Findings suggest that supplemental testosterone may increase lean body mass during short-term severe energy deficit in non-obese, young men, but it does not appear to attenuate lower-body functional decline. FUNDING: Collaborative Research to Optimize Warfighter Nutrition projects I and II, Joint Program Committee-5, funded by the US Department of Defence