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Oceanic anoxic events (OAEs) are historical intervals of global-scale ocean deoxygenation associated with hyperthermal climate states and biological crises1,2. Massive volcanic carbon dioxide (CO2) emissions frequently associated with these events are thought to be a common driver of ocean deoxygenation through several climate-warming-related mechanisms1,3,4. The Early Cretaceous OAE1a is one of the most intense ocean deoxygenation events, persisting for more than 1 Myr (refs. 5,6). However, existing records of marine chemistry and climate across OAE1a are insufficient to fully resolve the timing and dynamics of the underlying processes, thus obscuring cause-and-effect relationships between climate forcing and ocean oxygenation states. Here we show that rapid ocean deoxygenation during OAE1a is linked to volcanic CO2emissions and the crossing of an associated climate threshold, after which the sluggish pace of the silicate-weathering feedback and climate recovery delayed reoxygenation for >1 Myr. At the end of OAE1a, recrossing this threshold allowed for ocean reoxygenation. Following OAE1a, however, the Earth system remained sufficiently warm such that orbitally forced climate dynamics led to continued cyclic ocean deoxygenation on approximately 100-kyr timescales for another 1 Myr. Our results thus imply a tight coupling between volcanism, weathering and ocean oxygen content that is characterized by a climate threshold.

IMPORTANCE: Black adolescents are at increased risk of contracting HIV and other sexually transmitted infections (STIs) and experiencing unplanned pregnancy. Although sexual health interventions aimed at decreasing these risks exist, evidence of the association between sexual health interventions and the sexual behavior of black adolescents has not been synthesized to our knowledge. OBJECTIVE: To examine the associations between sexual health interventions and behavioral, biological, and psychological outcomes. DATA SOURCES: For this systematic review and meta-analysis, a systematic search was conducted of studies published through January 31, 2019, using the PubMed, PsycINFO, and CINAHL databases and relevant review articles. The following key words were used: youth, adolesc* or teen*; sexual health or safe* sex or sexually transmitted disease or sexually transmitted infection or STD or STI or HIV or AIDS or pregnancy or reproductive health or condom* or contracept* or unprotected sex or abstinence; intervention or program or education or prevention or promotion or trial; latino* or latina* or latinx* or minorit* or ethnic* or hispanic or african american* or black* or race or racial or biracial. STUDY SELECTION: Studies were included if they included a US-based sample of black adolescents, evaluated a sexual health intervention using experimental or quasi-experimental designs, included a behavioral outcome, and were published in English. DATA EXTRACTION AND SYNTHESIS: Standardized mean differences and 95% CIs were extracted and meta-analyzed using random-effects models. MAIN OUTCOMES AND MEASURES: Behavioral outcomes were abstinence, condom use, and number of sex partners. Biological outcomes were pregnancy and STI contraction. Psychological outcomes were sexual health intentions, knowledge, and self-efficacy. RESULTS: Across 29 studies including 11 918 black adolescents (weighted mean age, 12.43 years), there was a significant weighted mean association of sexual health interventions with improvements in abstinence (Cohen d = 0.14; 95% CI, 0.05-0.24) and condom use (Cohen d = 0.25; 95% CI, 0.11-0.39). No significant mean association of these interventions with number of sex partners, pregnancy, or STI contraction was found. Sexual health interventions were significantly associated with improvements in psychological outcomes: sexual health intentions (Cohen d = 0.17; 95% CI, 0.05-0.30), knowledge (Cohen d = 0.46; 95% CI, 0.30-0.63), and self-efficacy (Cohen d = 0.19; 95% CI, 0.09-0.28). Intervention effect sizes were consistent across factors, such as participant sex and age and intervention dose. CONCLUSIONS AND RELEVANCE: The findings suggest that sexual health interventions are associated with improvements in sexual well-being among black adolescents. There appears to be a need for wide-scale dissemination of these programs to address racial disparities in sexual health across the US.

The kinematic and exhumational evolution of the Lesser Himalaya (LH) remains a topic of debate. In NW India, the stratigraphically diverse LH is separated into the inner LH (iLH) of late Paleo‐Mesoproterozoic rocks and the outer LH (oLH) of Cryogenian to Cambrian rocks. Contradictory models regarding the age and structural affinity of the Tons thrust—a prominent structure bounding the oLH and iLH—are grounded in conflicting positions of the oLH prior to Himalayan orogenesis. This study presents new zircon (U‐Th)/He and U‐Pb ages from the thrust belt and foreland basin of NW India that refine the kinematic and exhumational evolution of the LH. Combined cooling ages and foreland provenance data support emplacement and unroofing of the oLH via southward in‐sequence propagation of the Tons thrust by middle Miocene time. This requires that, before India–Asia collision, the oLH was positioned as the southernmost succession of Neoproterozoic–Cambrian strata along the north Indian margin. This is further supported by detrital zircon U‐Pb ages from Cretaceous–Paleogene strata (Singtali Formation) unconformably overlying the oLH, which yield diagnostic Cretaceous detrital zircons correlative with coeval strata in the frontal Himalaya of Nepal. A pulse of rapid exhumation along the Tons thrust front at ~16 Ma was followed by east‐to‐west development of a midcrustal ramp at ~12 Ma which facilitated diachronous iLH duplexing. This duplexing shifted the locus of maximum exhumation northward, eroding away Main Central Thrust hanging wall rocks until the iLH breached the surface at ~9–11 Ma near Nepal and by ~3–7 Ma within the Kullu‐Rampur window. Zircon (U‐Th)/He ages reveal focused exhumation of outer Lesser Himalayan rocks at ~16–17 Ma along the Tons‐Berinag frontal thrust rampLesser Himalayan duplexing along a midcrustal ramp initiated by 11 Ma and propagated westward to its terminus near the Kullu‐Rampur windowDuplexing shifted focused exhumation northward, removing MCT hanging wall rocks until diachronous unroofing of the inner Lesser Himalaya

Reconstructing the stratigraphic architecture of deposits prior to Cenozoic Himalayan uplift is critical for unravelling the structural, metamorphic, depositional and erosional history of the orogen. The nature and distribution of Proterozoic and lower Paleozoic strata have helped elucidate the relationship between lithotectonic zones, as well as the geometries of major bounding faults. Stratigraphic and geochronological work has revealed a uniform and widespread pattern of Paleoproterozoic strata >1.6 Ga that are unconformably overlain by <1.1 Ga rocks. The overlying Neoproterozoic strata record marine sedimentation, including a Cryogenian diamictite, a well-developed carbonate platform succession and condensed fossiliferous Precambrian–Cambrian boundary strata. Palaeontological study of Cambrian units permits correlation from the Indian craton through three Himalayan lithotectonic zones to a precision of within a few million years. Detailed sedimentological and stratigraphic analysis shows the differentiation of a proximal realm of relatively condensed, nearshore, evaporite-rich units to the south and a distal realm of thick, deltaic deposits to the north. Thus, Neoproterozoic and Cambrian strata blanketed the northern Indian craton with an extensive, northward-deepening, succession. Today, these rocks are absent from parts of the inner Lesser Himalaya, and the uplift and erosion of these proximal facies explains a marked change in global seawater isotopic chemistry at 16 Ma.

Abstract ID 19624

We present empirical data on flight speed for 30 species of Australian bats representing seven families. These data show five characteristic level flight speeds: ‘minimum’ (Vmin), ‘best efficiency’ (Veff), ‘most common’ (Vmode), ‘maximum cruise’ (Vmcr) and ‘maximum spurt’ (Vmsp). Next, we calculate Vmin, Veff, ‘maximum aerobic’ (Vae), ‘sustainable anaerobic’ (Vsan) and ‘maximum anaerobic’ (Vman) flight speeds using a published quasi-steady model. Model predictions were within 0.5 m s−1of the empirical values for all five characteristic speeds given adequate samples. Model fidelity was cross-checked using flight speed data published for other Old and New World species.

Earth owes its oxygenated atmosphere to its unique claim on life, but how the atmosphere evolved from an initially oxygen-free state remains unresolved. The rise of atmospheric oxygen occurred in two stages: approximately 2.5 to 2.0 billion years ago during the Great Oxidation Event and roughly 2 billion years later during the Neoproterozoic Oxygenation Event. We propose that the formation of continents about 2.7 to 2.5 billion years ago, perhaps due to the initiation of plate tectonics, may have led to oxygenation by the following mechanisms. In the first stage, the change in composition of Earth's crust from iron- and magnesium-rich mafic rocks to feldspar- and quartz-rich felsic rocks could have caused a decrease in the oxidative efficiency of the Earth's surface, allowing atmospheric O2to rise. Over the next billion years, as carbon steadily accumulated on the continents, metamorphic and magmatic reactions within this growing continental carbon reservoir facilitated a gradual increase in the total long-term input of CO2to the ocean–atmosphere system. Given that O2is produced during organic carbon burial, the increased CO2input may have triggered a second rise in O2. A two-step rise in atmospheric O2may therefore be a natural consequence of plate tectonics, continent formation and the growth of a crustal carbon reservoir.

A link between CO2outgassing from carbonatite volcanoes during the Ediacaran and one of the most prominent carbon cycle perturbations in Earth’s history is suggested by an analysis of the trace-element composition of detrital zircons.

Previous bat aerodynamic power models are refined by (1) varying the value of wing profile drag with lift coefficient, which varies with both flight speed and Reynolds number, (2) allowing for the aerodynamic cleanliness of head, body, ears and tail in calculating parasitic drag values at various speeds and according to airframe type, (3) incorporating models of wingbeat amplitude and frequency in the power calculations, and, (4) upgrading the allometric, phylogenetically corrected relationship between basal metabolic rate and body mass using data from 98 bat species. The fidelity of the aerodynamic power model is assessed using published wind tunnel data on a bat in steady glide. By comparing empirical published metabolic power (Pmet) values with values derived using the new aerodynamic model, we update estimates of in-flight musculoskeletal mechanical efficiency (η) for the airframes of eight bat species at steady level flight speeds. Furthermore, we calculate the increase in ηat high speeds. The bats assessed range in body mass from 0.01 to 1 kg, and the comparison covers the speed range normally used by free-flying bats during their excursions. At their best endurance flight speeds (Vend), η= 1.52 Ln (mbat) + 11.44 (%). At speeds > Vend, η= η@Vend+ 1.3 (V−Vend) (%). These equations yield accurate Pmetestimates for flight speeds within the range used for the steady level flight.

Organic carbon and nitrogen found in soils are subject to a range of biological processes capable of generating or consuming greenhouse gases (CO2, N2O and CH4). In response to the strong impact that agricultural management can have on the amount of organic carbon and nitrogen stored in soil and their rates of biological cycling, soils have the potential to reduce or enhance concentrations of greenhouse gases in the atmosphere. Concern also exists over the potential positive feedback that a changing climate may have on rates of greenhouse gas emission from soil. Climate projections for most of the agricultural regions of Australia suggest a warmer and drier future with greater extremes relative to current climate. Since emissions of greenhouse gases from soil derive from biological processes that are sensitive to soil temperature and water content, climate change may impact significantly on future emissions. In this paper, the potential effects of climate change and options for adaptation and mitigations will be considered, followed by an assessment of future research requirements. The paper concludes by suggesting that the diversity of climate, soil types, and agricultural practices in place across Australia will make it difficult to define generic scenarios for greenhouse gas emissions. Development of a robust modelling capability will be required to construct regional and national emission assessments and to define the potential outcomes of on-farm management decisions and policy decisions. This model development will require comprehensive field datasets to calibrate the models and validate model outputs. Additionally, improved spatial layers of model input variables collected on a regular basis will be required to optimise accounting at regional to national scales.

This study evaluated the accuracy of pressure plate apparatus for measuring soil water retention at −0.5 and −1.5 MPa matric potential. Samples from 35 contrasting Australian soils were wetted with distilled water and drained on pressure plate apparatus at −0.5 and −1.5 MPa. The soil matric potential of each sample was then determined using a thermocouple psychrometer, and water content was measured. Water content at exactly −0.5 and −1.5 MPa matric potential was determined independently by interpolating between replicates of matric potential–water content data measured using a thermocouple psychrometer. Water content of the soil samples at apparent equilibrium on pressure plates was compared with these “target” water contents. The 35 samples on pressure plates at −1.5 MPa equilibrated, on average, to 0.3% (w/w) wetter than the target water content, with mean matric potential of −1.10 MPa. Fifteen samples were significantly wetter than the target values. Soil samples on pressure plates at −0.5 MPa equilibrated, on average, to 0.2% (w/w) wetter than the target water content, attaining a mean matric potential of −0.48 MPa. Mean error in water content at −1.5 MPa on pressure plates was reduced from >0.5 to <0.1% (w/w) in a subset of 10 samples prone to dispersion by wetting with 0.01 mol L−1CaCl2Water contents of samples equilibrated on pressure plates at −1.5 MPa were good estimates of “true” −1.5 MPa water content for the nonswelling soils tested, provided CaCl2was used to minimize dispersion. Vapor equilibrium measurement methods are recommended for swelling soils.

Off-pump coronary artery bypass (OPCAB) surgery has been successfully used in diverse patient populations and has been postulated to be safer than conventional coronary artery bypass (CCAB) surgery in some high-risk patients, including the elderly.

The Australian bat Tadarida australis has a peculiar geographical niche that involves a continental-scale movement of over 10 of latitude in Western Australia. Its range expands northward by up to 1200 km for the winter and contracts southward for the summer. Its summer range limit correlates with an interaction of temperature and humidity, best summarised by atmospheric enthalpy. Its winter distribution is expanded northward within the enthalpy threshold, but appears to be further restricted in some areas by an unknown factor that may be biotic. We propose a potential competitor and a potential predator that may have strongly negative interactions in these regions. The 1% of records that are beyond the enthalpy envelope are from the change-over months and may be an artefact of year-to-year climatic variation. Three climatic thresholds enclose the enthalpy envelope: average annual rainfall >10 mm per month and <50 mm per month, and average overnight minimum temperature <20C. Current literature relates migration of temperate-zone bats to resource availability as a consequence of changing season. We identify a tight correlation with atmospheric enthalpy that points to dissipation of flight muscle heat as a limiting factor.

The primary flight muscles of the chest, shoulder, back and upper arms were weighed for 29 species of Australian bat, representing two suborders and six families. Values of muscle masses were found to be between 9 and 23% of the mass of the bat (mbat) and aligned into three statistically distinct classes that relate foraging strategy with morphology when plotted against mbat. These classes represent 'high-energy', 'general' and 'low-energy' foraging strategies. The above relationships were visible in both the wing downstroke and upstroke muscle groups, but not in the shoulder and elbow flex/extend groups. Differences in the foraging ecologies and geographical distributions of Western Australian bats are reflected in 'flight motor power output' as well as the bats' 'airframe design' attributes. Based on these attributes and ecologies, a method is presented for estimating the mass of flight muscle.

We investigated differences between constant flux and constant potential methods for determining unsaturated hydraulic conductivity in the laboratory. A cheap and robust method was required. The constant flux drip infiltrometer has been used with large intact cores on a wide range of Australian soils. However, the method can be simplified by replacing the drip infiltrometer with a constant potential tension infiltrometer (disc permeameter). We conducted a series of measurements using 9 soil cores to determine whether the measured hydraulic conductivity differed with each method at matric potentials of –10, –20, or –50 mm. Hysteresis effects were also examined because tension infiltrometer measurements are usually made on the adsorption curve of the hydraulic conductivity and matric potential [K(Ψ)] relationship. Drip infiltrometer measurements are often made on the desorption curve. The reproducibility of measurements on a single core was also examined. A large decline in K(Ψ ) was observed on some cores with repeated measurements and this effect was larger than differences between the methods. In the absence of evidence of slaking or dispersion, the suspected cause of the decline in K(Ψ) was clogging of pores from accumulation of microbial biomass and their by-products. The results support the view that K(Ψ) in some soils is a dynamic property. There were consistent differences between the constant flux and constant potential methods on those soil cores not exhibiting a large decline in K(Ψ) (the others were omitted from the method comparison). The tension infiltrometer method indicated greater hydraulic conductivity in soils with well-developed macrostructure when matric potential was greater than –50 mm. Hysteresis effects were significant with both methods and measurements made on desorption and adsorption curves are not considered comparable. Overall, we concluded that the tension infiltrometer method was more suited than the drip method for routine processing of large numbers of samples at low cost. soil survey, land evaluation.

We tested the airframes of a community of microbats in terms of flight performance, stability and control, and present the first systematic classification of bat flight manoeuvres. The tail, ears and main-wing all contributed to these airframe functions. In combination, six airframe ratios (aspect ratio, wing loading, tail area ratio, ear area ratio, tail length ratio and ear length ratio) provided robust predictions of species’ foraging microhabitats and foraging strategies (including agility and speed).

Explicit and quantitative models for the spatial prediction of soil and landscape attributes are required for environmental modelling and management. In this study, advances in the spatial representation of hydrological and geomorphological processes using terrain analysis techniques are integrated with the development of a field sampling and soil-landscape model building strategy. Statistical models are developed using relationships between terrain attributes (plan curvature, compound topographic index, upslope mean plan curvature) and soil attributes (A horizon depth, Solum depth, E horizon presence/absence) in an area with uniform geology and geomorphic history. These techniques seem to provide appropriate methodologies for spatial prediction and understanding soil landscape processes.

Lean (Fa/-) and genetically obese (fa/fa) Zucker rats were adrenalectomized at 18 days of age (3 days before weaning) before the onset of hyperinsulinaemia. At 40–41 days of age, basal and glucose-stimulated insulin concentrations did not differ significantly between lean and obese rats. Plasma insulin and glucose concentrations were higher in both phenotypes 24 h after administration of corticosterone (2·0 mg at 12-h intervals). Corticosterone-treated obese rats had higher basal and glucose-stimulated insulin levels than similarly treated lean animals, although plasma glucose concentrations did not differ between phenotypes. The basal plasma insulin concentration of obese rats treated with corticosterone for 24 h was reduced 15, 30 and 45 min after injection of atropine (0·3 mg) without any significant change in the plasma glucose level. Injection of atropine (0·3 mg) 20 min before a glucose load prevented the greater increment in plasma insulin concentration of corticosterone-treated obese rats compared with similarly treated lean animals. Atropine administration (0·3 mg) to intact obese rats at 40 days of age reduced, but did not abolish, their hyperinsulinaemia compared with intact lean animals. It is concluded that (1) pre-weaning adrenalectomy prevents the development of hyperinsulinaemia in genetically obese rats, (2) corticosterone replacement for only 24 h restores the hyperinsulinaemia of obese rats, (3) the differential effects of corticosterone on insulin secretion by lean and obese rats are mediated by the parasympathetic nervous system and (4) the parasympathetic nervous system contributes to, but is not the only cause of, hyperinsulinaemia in intact obese rats.J. Endocr. (1988) 118,87–92

Objective To determine whether rewording postal reminder cards according to the "health belief model", a theory about preventive health behaviour, would help to improve measles vaccination rates. Design A randomised controlled trial, with blind assessment of outcome status. Parents of children due for their first measles vaccination were randomised to one of two groups, one receiving the health belief model reminder card, the other receiving the usual, neutrally worded card. The proportion of children subsequently vaccinated in each group over a five week period was ascertained from clinical (provider based) records. Setting A local government operated public vaccination clinic. Participants Parents of 259 children due for measles vaccination. Main results The proportion of children vaccinated in the health belief model card group was 79% compared with 67% of those sent the usual card (95% CI, 2% to 23%), a modest but important improvement. Conclusion This study illustrates how the effectiveness of a minimal and widely practised intervention to promote vaccination compliance can be improved with negligible additional effort.

Understanding the effects of flat slab subduction on mountain building, arc magmatism, and basin evolution is fundamental to convergent‐margin tectonics, with implications for potential feedbacks among geodynamic, magmatic, and surface processes. New stratigraphic and geochronological constraints on Cenozoic sedimentation and magmatism in the southern Central Andes of Argentina (31°S) reveal shifts in volcanism, foreland/hinterland basin development, sediment accumulation, and provenance as the retroarc region was structurally partitioned during slab flattening. Detrital zircon U‐Pb age distributions from the western (Calingasta basin), central (Talacasto and Albarracín basins), and eastern (Bermejo foreland basin) segments of the retroarc basin system preserve syndepositional volcanism and orogenic unroofing of multiple tectonic provinces. Initial shortening‐related exhumation of the Principal Cordillera at 24–17 Ma was recorded by the accumulation of distal eolian deposits bearing Oligocene–Eocene zircons from the Andean magmatic arc. The Calingasta basin chronicled volcanism and basement shortening in the Frontal Cordillera at ~17–11 Ma, as marked by an upward coarsening succession of fluvial to alluvial fan deposits with a sustained zircon U‐Pb age component that matches pervasive Permian‐Triassic bedrock in the hinterland. An ~450 km eastward inboard sweep of volcanism at 11 Ma coincided with the inception of flat slab subduction, and subsequent thin‐skinned shortening in the Precordillera fold‐thrust belt that exhumed wedge‐top deposits and induced cratonward (eastward) advance of flexural subsidence into the Bermejo foreland basin. This foreland basin was structurally partitioned as basement uplifts of the Sierras Pampeanas transformed a fluvial megafan sediment routing network into smaller isolated alluvial fan systems fed by adjacent basement blocks. Andean retroarc basin was structurally partitioned into isolated hinterland and broken foreland basins during subduction shallowingClastic progradational deposystems and orogenic unroofing signatures are associated with sequential Andean deformationFlat slab subduction drove the advance of the Andean magmatic front >450 km eastward into the foreland at 10 Ma

The existence of stabilizing feedbacks within Earth's climate system is generally thought to be necessary for the persistence of liquid water and life. Over the course of Earth's history, Earth's atmospheric composition appears to have adjusted to the gradual increase in solar luminosity, resulting in persistently habitable surface temperatures. With limited exceptions, the Earth system has been observed to recover rapidly from pulsed climatic perturbations. Carbon dioxide (CO2) regulation via negative feedbacks within the coupled global carbon‐silica cycles are classically viewed as the main processes giving rise to climate stability on Earth. Here we review the long‐term global carbon cycle budget, and how the processes modulating Earth's climate system have evolved over time. Specifically, we focus on the relative roles that shifts in carbon sources and sinks have played in driving long‐term changes in atmospheric pCO2. We make the case that marine processes are an important component of the canonical silicate weathering feedback, and have played a much more important role in pCO2regulation than traditionally imagined. Notably, geochemical evidence indicate that the weathering of marine sediments and off‐axis basalt alteration act as major carbon sinks. However, this sink was potentially dampened during Earth's early history when oceans had higher levels of dissolved silicon (Si), iron (Fe), and magnesium (Mg), and instead likely fostered more extensive carbon recycling within the ocean‐atmosphere system via reverse weathering—that in turn acted to elevate ocean‐atmosphere CO2levels. Long term carbon sources and sinks are likely larger than traditional envisionedThere is significant silicate weathering in the marine as well as terrestrial settingsOcean oxygenation and evolution of a biotic Si cycle forced a drop in reverse weathering rates and an increase in marine weathering rates