Geoengineering: A war on climate change?

Geoengineering; specifically Solar Radiation Management ; has been proposed to effect rapid influence over the Earth’s climate system in order to counteract Anthropogenic Global Warming. This poses near-term to long-term governance challenges; some of which are within the planning horizon of current political administrations. Previous discussions of governance of SRM have focused primarily on two scenarios: an isolated “Greenfinger” individual; or state; acting independently ; versus more consensual; internationalist approaches. I argue that these models represent a very limited sub-set of plausible deployment scenarios. To generate a range of alternative models; I offer a short; relatively unstructured discussion of a range of different types of warfare – each with an analogous SRM deployment regime

Solar Radiation Management and the Voluntary Carbon Market

Climate models suggest that Solar Radiation Management (SRM), such as by means of Stratospheric Aerosol Injection, could counteract the warming effects of greenhouse gases, though not with total effectiveness. As far as the regulation of SRM is concerned, scholars have focused typically on public, state-based regimes such as those provided by international treaties. The evidence suggests that SRM may also cause a reduction in atmospheric CO2, thereby creating potential carbon credit accrual. The emergence of private interests, in the form of credits tradeable in the voluntary carbon markets, represents a new challenge for the effective public regulation of SRM. Without an appropriate response, major, novel and potentially unacceptable risks to the climate system, biosphere and society may occur. </jats:p

Protein adsorption onto ultrafiltration membranes

Ultrafiltration, the use of a semi-permeable membrane to facilitate the separation of molecules in solution, is a widely-used process. It is however far from fully understood in many respects. The relationship between the nominal molecular weight cut-off ascribed to a membrane by a manufacturer (90% of spherical, uncharged molecules of this weight should theoretically be retained) and its behaviour in actual use is not always predictable. Other physical and chemical properties of the filter may also be of importance. Ultrafiltration is the result of a variety of subtle interactions between various components. [Continues.

An update on engineering issues concerning stratospheric aerosol injection for geoengineering

Abstract: Solar Radiation Management (SRM) geoengineering is a proposed response to anthropogenic global warming (AGW). Stratospheric aerosol injection (SAI) is one proposed method, reliant on lofting material into the stratosphere. Engineering reviews related to this technology approach have been sparse, with most major primary analyses now at least five years old. We attempt to bridge this gap—with a short, qualitative review of recent developments in various fields of engineering that have potential applicability to SAI. Our analysis shows that a new conventional aircraft design is still likely to be the most dependable and affordable technology solution (cost estimates start around $1000–1500 per ton lofted), with hybrid or vacuum airships a potential challenger. Rockets, gas guns and MAGLEV/coilguns show some potential—although they lack the inherent level-flight capability that would be needed for direct aerosol distribution (versus distribution of gaseous precursors), without substantial additional engineering. Should very high-altitude access be required, rockets, jet-hybrid rockets, and various guns (especially light-gas guns) potentially offer the required capability. Costs and performance for tethered balloons remain highly uncertain. Towers are not found to be promising. The extreme accessibility of free balloons suggests that this method may be used primarily for reasons of political leverage, as opposed to being an optimal engineering solution

Evaluating rainbowing for ocean alkalinity enhancement

Ocean Alkalinity Enhancement (OAE) is a technique proposed to address ocean acidification and global warming. This study examines rainbowing (i.e. water jets pumped into the air from ships) for the slaked lime slurry distribution. The fluid dynamic behaviour-both the in-air trajectory and subsurface-was studied using the Smoothed Particle Hydrodynamics method. Various outflow velocities were simulated for calm seas; different dilution factors and environmental slaked lime concentration spikes have been found. Linking slurry concentration to pH, discharge conditions that avoid damage to marine biota have been identified. A preliminary cost analysis compares rainbowing to ship-wake discharge. Rainbowing requires high power consumption to project large volumes of water far from ships. Very high dilution is needed, mainly because of the artificial requirement not to momentarily exceed 24-hour environmental pH limits; the effect of ocean turbulence on instantaneous pH peaks is negligible and is not considered in the analysis. Emissions due to energy consumption almost equalize carbon dioxide removed during discharge, making the method inefficient (only 176 kg of CO2 removed per ton of slaked lime spread). Previous ship-wake discharge analysis shows greater OAE performance and lower cost (5.5 versus 388 per ton of CO2 removed). In conclusion-based on the conservative environmental limits imposed, and the specific modeling undertaken-rainbowing is not demonstrated as an efficient method for OAE

Accurate detection of acute sleep deprivation using a metabolomic biomarker—A machine learning approach

Sleep deprivation enhances risk for serious injury and fatality on the roads and in workplaces. To facilitate future management of these risks through advanced detection, we developed and validated a metabolomic biomarker of sleep deprivation in healthy, young participants, across three experiments. Bi-hourly plasma samples from 2 × 40-hour extended wake protocols (for train/test models) and 1 × 40-hour protocol with an 8-hour overnight sleep interval were analyzed by untargeted liquid chromatography–mass spectrometry. Using a knowledge-based machine learning approach, five consistently important variables were used to build predictive models. Sleep deprivation (24 to 38 hours awake) was predicted accurately in classification models [versus well-rested (0 to 16 hours)] (accuracy = 94.7%/AUC 99.2%, 79.3%/AUC 89.1%) and to a lesser extent in regression (R2 = 86.1 and 47.8%) models for within- and between-participant models, respectively. Metabolites were identified for replicability/future deployment. This approach for detecting acute sleep deprivation offers potential to reduce accidents through “fitness for duty” or “post-accident analysis” assessments

Higher central circadian temperature amplitude is associated with greater metabolite rhythmicity in humans

Robust circadian rhythms are essential for optimal health. The central circadian clock controls temperature rhythms, which are known to organize the timing of peripheral circadian rhythms in rodents. In humans, however, it is unknown whether temperature rhythms relate to the organization of circadian rhythms throughout the body. We assessed core body temperature amplitude and the rhythmicity of 929 blood plasma metabolites across a 40-h constant routine protocol, controlling for behavioral and environmental factors that mask endogenous temperature rhythms, in 23 healthy individuals (mean [± SD] age = 25.4 ± 5.7 years, 5 women). Valid core body temperature data were available in 17/23 (mean [± SD] age = 25.6 ± 6.3 years, 1 woman). Individuals with higher core body temperature amplitude had a greater number of metabolites exhibiting circadian rhythms (R2 = 0.37, p = .009). Higher core body temperature amplitude was also associated with less variability in the free-fitted periods of metabolite rhythms within an individual (R2 = 0.47, p = .002). These findings indicate that a more robust central circadian clock is associated with greater organization of circadian metabolite rhythms in humans. Metabolite rhythms may therefore provide a window into the strength of the central circadian clock

Bird-Like Anatomy, Posture, and Behavior Revealed by an Early Jurassic Theropod Dinosaur Resting Trace

BACKGROUND: Fossil tracks made by non-avian theropod dinosaurs commonly reflect the habitual bipedal stance retained in living birds. Only rarely-captured behaviors, such as crouching, might create impressions made by the hands. Such tracks provide valuable information concerning the often poorly understood functional morphology of the early theropod forelimb. METHODOLOGY/PRINCIPAL FINDINGS: Here we describe a well-preserved theropod trackway in a Lower Jurassic ( approximately 198 million-year-old) lacustrine beach sandstone in the Whitmore Point Member of the Moenave Formation in southwestern Utah. The trackway consists of prints of typical morphology, intermittent tail drags and, unusually, traces made by the animal resting on the substrate in a posture very similar to modern birds. The resting trace includes symmetrical pes impressions and well-defined impressions made by both hands, the tail, and the ischial callosity. CONCLUSIONS/SIGNIFICANCE: The manus impressions corroborate that early theropods, like later birds, held their palms facing medially, in contrast to manus prints previously attributed to theropods that have forward-pointing digits. Both the symmetrical resting posture and the medially-facing palms therefore evolved by the Early Jurassic, much earlier in the theropod lineage than previously recognized, and may characterize all theropods

Neoadjuvant Chemotherapy Modulates the Immune Microenvironment in Metastases of Tubo-Ovarian High-Grade Serous Carcinoma

This research was funded by Swiss Cancer League (BIL KLS-2883-02-2012), the European Research Council (ERC322566), Cancer Research UK (A16354), and Barts and The London Charity (467/1307)

The Impact of Duty Hours on Resident Self Reports of Errors

BACKGROUND: Resident duty hour limitations aim, in part, to reduce medical errors. Residents’ perceptions of the impact of duty hours on errors are unknown. OBJECTIVE: To determine residents’ self-reported contributing factors, frequency, and impact of hours worked on suboptimal care practices and medical errors. DESIGN: Cross-sectional survey. SUBJECTS: 164 Internal Medicine Residents at the University of California, San Francisco. MEASUREMENTS AND RESULTS: Residents were asked to report the frequency and contributing factors of suboptimal care practices and medical errors, and how duty hours impacted these practices and aspects of resident work-life. One hundred twenty-five residents (76%) responded. The most common suboptimal care practices were working while impaired by fatigue and forgetting to transmit information during sign-out. In multivariable models, residents who felt overwhelmed with work (p = 0.02) and who reported spending >50% of their time in nonphysician tasks (p = 0.002) were more likely to report suboptimal care practices. Residents reported work-stress (a composite of fatigue, excessive workload, distractions, stress, and inadequate time) as the most frequent contributing factor to medical errors. In multivariable models, only engaging in suboptimal practices was associated with self-report of higher risk for medical errors (p < 0.001); working more than 80 hours per week was not associated with suboptimal care or errors. CONCLUSION: Our findings suggest that administrative load and work stressors are more closely associated with resident reports of medical errors than the number of hours work. Efforts to reduce resident duty hours may also need to address the nature of residents’ work to reduce errors