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The search for life in the Universe is a fundamental problem of astrobiology and modern science. The current progress in the detection of terrestrial-type exoplanets has opened a new avenue in the characterization of exoplanetary atmospheres and in the search for biosignatures of life with the upcoming ground-based and space missions. To specify the conditions favourable for the origin, development and sustainment of life as we know it in other worlds, we need to understand the nature of global (astrospheric), and local (atmospheric and surface) environments of exoplanets in the habitable zones (HZs) around G-K-M dwarf stars including our young Sun. Global environment is formed by propagated disturbances from the planet-hosting stars in the form of stellar flares, coronal mass ejections, energetic particles and winds collectively known as astrospheric space weather. Its characterization will help in understanding how an exoplanetary ecosystem interacts with its host star, as well as in the specification of the physical, chemical and biochemical conditions that can create favourable and/or detrimental conditions for planetary climate and habitability along with evolution of planetary internal dynamics over geological timescales. A key linkage of (astro)physical, chemical and geological processes can only be understood in the framework of interdisciplinary studies with the incorporation of progress in heliophysics, astrophysics, planetary and Earth sciences. The assessment of the impacts of host stars on the climate and habitability of terrestrial (exo)planets will significantly expand the current definition of the HZ to the biogenic zone and provide new observational strategies for searching for signatures of life. The major goal of this paper is to describe and discuss the current status and recent progress in this interdisciplinary field in light of presentations and discussions during the NASA Nexus for Exoplanetary System Science funded workshop ‘Exoplanetary Space Weather, Climate and Habitability’ and to provide a new roadmap for the future development of the emerging field of exoplanetary science and astrobiology.
Multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS) is a powerful technique for the study of biogeochemical cycling of a variety of metals. The advantages of this technique include high ionization efficiency, low detection limits, and rapid analysis. It can produce highly precise and accurate elemental isotope compositions of natural and experimental samples, which can provide insights into the mechanisms of both biological and abiological processes in in natural environments. In this chapter, the operating principles of the instrument, purification of samples, interferences encountered, correction methods to eliminate the instrumental mass discrimination, and data analysis with respect to reliability and reproducibility are discussed. A case study is included that highlights the capability of MC-ICP-MS to infer mechanisms of Fe redox processes in an acidic oligotrophic lake using natural abundance of stable Fe isotopes.
The overarching goal of this work is to support creative ideation in engineering design with the aim of overcoming design fixation. We study the impact of abstract representations and ways to frame the problem in design briefs on the creativity of concept sketches. Framing/Reframing involves shifting perspectives on the design purpose and to reveal insights and opportunities. Two Framing/Reframing techniques are tested: the Ishikawa/Fishbone Diagram to identify root causes and a blend of Parnes’ Restatement/SCAMPER method to encourage divergence in problem perception. Abstract representations of requirements were used as stimuli to foster transfer and associative thinking. Using a full-factorial experimental design with brief variations, C-Sketch ideas developed by first-year engineering/architecture students were evaluated for their creativity. Our results showed a positive interaction effect for novelty and usefulness when the Fishbone Reframing method was used with abstract representation, but there was no difference in creativity scores when comparing the two Framing/Reframing methods between each other.
The initial classic Fontan utilising a direct right atrial appendage to pulmonary artery anastomosis led to numerous complications. Adults with such complications may benefit from conversion to a total cavo-pulmonary connection, the current standard palliation for children with univentricular hearts.
A single institution, retrospective chart review was conducted for all Fontan conversion procedures performed from July, 1999 through January, 2017. Variables analysed included age, sex, reason for Fontan conversion, age at Fontan conversion, and early mortality or heart transplant within 1 year after Fontan conversion.
A total of 41 Fontan conversion patients were identified. Average age at Fontan conversion was 24.5 ± 9.2 years. Dominant left ventricular physiology was present in 37/41 (90.2%) patients. Right-sided heart failure occurred in 39/41 (95.1%) patients and right atrial dilation was present in 33/41 (80.5%) patients. The most common causes for Fontan conversion included atrial arrhythmia in 37/41 (90.2%), NYHA class II HF or greater in 31/41 (75.6%), ventricular dysfunction in 23/41 (56.1%), and cirrhosis or fibrosis in 7/41 (17.1%) patients. Median post-surgical follow-up was 6.2 ± 4.9 years. Survival rates at 30 days, 1 year, and greater than 1-year post-Fontan conversion were 95.1, 92.7, and 87.8%, respectively. Two patients underwent heart transplant: the first within 1 year of Fontan conversion for heart failure and the second at 5.3 years for liver failure.
Fontan conversion should be considered early when atrial arrhythmias become common rather than waiting for severe heart failure to ensue, and Fontan conversion can be accomplished with an acceptable risk profile.
The second order nonlinear optical (NLO) properties of two different ionic selfassembled multilayer (ISAM) films combined with Ag nanoparticles have been investigated. The plasmon resonances in the Ag particles concentrate the incident light, markedly increasing in the NLO efficiencies of the films. We find that the efficiency enhancement is significantly larger in conventional ISAM films compared to films made using a hybrid covalent ISAM technique (HCISAM), even though the intrinsic bulk second order non-linear susceptibility (χ(2)) is much larger for HCISAM films. We attribute this to the interfaces in HCISAM films being much easier to disrupt by external perturbations such as the metal deposition by which the nanoparticles are fabricated. We conclude that because the plasmon decay length is very short, the plasmonic enhancement of NLO effects primarily occurs at and near the film-particle interface. To discern the importance of the interfaces, we surrounded thin ISAM and HCISAM films with NLOinactive buffer layers, which confirmed this hypothesis, particularly in the case of HCISAM films.
Metal carbonyls are important for chemical vapor deposition (CVD) of metals and alloys and formation of high surface area metallic particles which have potential applications as catalysts. Rhodium carbonyl [Rh6(CO)16] produces high surface area metallic particles whose structure has been reported as monoclinic (I2/a) with lattice dimensions, a=17.00(±0.03)Å, b=9.78(±0.02)Å, c=17.53(±0.03)Å and β=121°45' ± 30' at room temperature. Generally, metal carbonyl crystals dissociate under vacuum as carbonyl gas and decompose to metallic crystals and carbon monoxide at higher temperatures. However, the behavior of rhodium carbonyl crystals is different; they decompose directly to metallic rhodium without the formation of rhodium carbonyl gas in vacuum. Several residual fine grains of rhodium metal are found after the decomposition in vacuum at relatively low temperatures. The metallic samples of rhodium were obtained from vapor pressure experiments using torsion Knudsen-effusion apparatus. X-ray diffraction analyses performed on these grains showed severely broadened Bragg reflections indicative of small particle size and/or lattice microstrain. In this study, a comparison of lattice strains and domain sizes obtained by integral breadth and Fourier methods has been made. In addition a comparison of the lattice strains and domain sizes has been made between the Cauchy, Gaussian, Cauchy-Gaussian and Aqua integral breadth methods.
In this article we rethink the connection between prosecutorial experience and conviction psychology that undergirds much of the academic literature about wrongful convictions. The conviction psychology account of prosecutorial behavior asserts that prosecutorial susceptibility to cognitive biases deepens over time, thereby increasing the risk that prosecutors will become involved in wrongful convictions the longer they stay in the profession. Our interviews with more than 200 state prosecutors call into question the basis for this asserted correlation between prosecutorial experience and risk of misconduct. The prosecutors we met consistently reported that, all else equal, prosecutors tend to become more balanced, rather than more adversarial, over time. Hence, the prosecutors who present the greatest risk of producing a wrongful conviction are those who are either inexperienced or resistant to the normal maturation process. For this reason, we suggest that wrongful conviction researchers and database designers pay closer attention to the variables associated with prosecutorial experience and resistance that might affect the development of prosecutorial maturity and the consequent risk of wrongful convictions.
In this article I offer a principled strategy for the courts to identify and to handle the uses of culture as a defense in a criminal proceeding. I begin by discussing the relationship between culture and behavior illuminated by sociologists of culture. I then explain the three categories into which cultural defenses fall–cultural reason, cultural requirement, and cultural tolerance–and the response of criminal courts in the United States to each. I argue that where culture offers an alternative explanation of the defendant's intent, it is highly relevant to determinations of criminal liability. However, where a defendant uses culture only to explain why he wanted to harm the victim and asks that the court be tolerant of such behavior, considerations of culture should not be allowed. In reaching this conclusion, I draw on theories of multiculturalism to consider the benefits and burdens of maintaining the facade of a “cultureless” criminal law in an increasingly heterogeneous society.
Recent evidence suggests that exercise plays a role in cognition and that the posterior cingulate cortex (PCC) can be divided into dorsal and ventral subregions based on distinct connectivity patterns.
To examine the effect of physical activity and division of the PCC on brain functional connectivity measures in subjective memory complainers (SMC) carrying the epsilon 4 allele of apolipoprotein E (APOE 4) allele.
Participants were 22 SMC carrying the APOE ɛ4 allele (ɛ4+; mean age 72.18 years) and 58 SMC non-carriers (ɛ4–; mean age 72.79 years). Connectivity of four dorsal and ventral seeds was examined. Relationships between PCC connectivity and physical activity measures were explored.
ɛ4+ individuals showed increased connectivity between the dorsal PCC and dorsolateral prefrontal cortex, and the ventral PCC and supplementary motor area (SMA). Greater levels of physical activity correlated with the magnitude of ventral PCC–SMA connectivity.
The results provide the first evidence that ɛ4+ individuals at increased risk of cognitive decline show distinct alterations in dorsal and ventral PCC functional connectivity.
The mixing of unfamiliar sows at weaning forces the establishment of dominance hierarchies, which frequently involves aggression (Kay et al, 1999). The objective of this study was to determine whether different stocking densities and pen shapes would reduce the incidence of aggression and levels of skin damage. The ultimate aim was to design a mixing pen which could be used to enhance the welfare of groups of newly-weaned sows.
The mixing of unfamiliar sows at weaning leads to aggression whilst dominance hierarchies within the group are established (Kay et al, 1999). The objective of this study was to determine whether the presence of a boar would reduce the incidence of aggression and level of skin damage of newly mixed sows. The overall aim of the project was to improve welfare by designing a suitable strategy for mixing groups of newly-weaned sows
Two-step, solar-driven thermochemical fuel production offers the potential of efficient conversion of solar energy into dispatchable chemical fuel. Success relies on the availability of materials that readily undergo redox reactions in response to changes in environmental conditions. Those with a low enthalpy of reduction can typically be reduced at moderate temperatures, important for practical operation. However, easy reducibility has often been accompanied by surprisingly poor fuel production kinetics. Using the La1−xSrxMnO3 series of perovskites as an example, we show that poor fuel production rates are a direct consequence of the diminished enthalpy. Thus, material development efforts will need to balance the countering thermodynamic influences of reduction enthalpy on fuel production capacity and fuel production rate.
To assess the level of all-hazards disaster preparedness and training needs of emergency department (ED) doctors and nurses in Hong Kong from their perspective, and identify factors associated with high perceived personal preparedness.
This study was a cross-sectional territory-wide online survey conducted from 9 September to 26 October, 2015.
The participants were doctors from the Hong Kong College of Emergency Medicine and nurses from the Hong Kong College of Emergency Nursing.
We assessed various components of all-hazards preparedness using a 25-item questionnaire. Backward logistic regression was used to identify factors associated with perceived preparedness.
A total of 107 responses were analyzed. Respondents lacked training in disaster management, emergency communication, psychological first aid, public health interventions, disaster law and ethics, media handling, and humanitarian response in an overseas setting. High perceived workplace preparedness, length of practice, and willingness to respond were associated with high perceived personal preparedness.
Given the current gaps in and needs for increased disaster preparedness training, ED doctors and nurses in Hong Kong may benefit from the development of core-competency-based training targeting the under-trained areas, measures to improve staff confidence in their workplaces, and efforts to remove barriers to staff willingness to respond. (Disaster Med Public Health Preparedness. 2018; 12: 329–336)
Accurately measuring and monitoring the thickness distribution of thin ice is crucial for accurate estimation of ocean–atmosphere heat fluxes and rates of ice production and salt flux in ice-affected oceans. Here we present results from helicopter-borne brightness temperature (TB) measurements in the Southern Ocean in October 2012 and in the Sea of Okhotsk in February 2009 carried out with a portable passive microwave (PMW) radiometer operating at a frequency of 36 GHz. The goal of these measurements is to aid evaluation of a satellite thin-ice thickness algorithm which uses data from the spaceborne Advanced Microwave Scanning Radiometer–Earth Observing System AMSR-E) or the Advanced Microwave Scanning Radiometer-II (AMSR-II). AMSR-E and AMSR-II TB agree with the spatially collocated mean TB from the helicopter-borne measurements within the radiometers’ precision. In the Sea of Okhotsk in February 2009, the AMSR-E 36GHz TB values are closer to the mean than the modal TB values measured by the helicopter-borne radiometer. In an Antarctic coastal polynya in October 2012, the polarization ratio of 36GHz vertical and horizontal TB is estimated to be 0.137 on average. Our measurements of the TB at 36 GHz over an iceberg tongue suggest a way to discriminate it from sea ice by its unique PMW signature.
To explore eating patterns and snacking among US infants, toddlers and pre-school children.
The Feeding Infants and Toddlers Study (FITS) 2008 was a cross-sectional national survey of children aged 6–47 months, weighted to reflect US age and racial/ethnic distributions. Dietary data were collected using one multiple-pass 24h recall. Eating occasions were categorized as meals, snacks or other (comprised of all feedings of breast milk and/or infant formula). The percentage of children consuming meals and snacks and their contribution to total energy, the number of snacks consumed per day, energy and nutrients coming from snacks and the most commonly consumed snacks were evaluated by age.
A national sample of US infants, toddlers and pre-school children.
A total of 2891 children in five age groups: 6–8 months (n 249), 9–11 months (n 256), 12–23 months (n 925), 24–35 months (n 736) and 36–47 months (n 725).
Snacks were already consumed by 37 % of infants beginning at 6 months; by 12 months of age, nearly 95 % were consuming at least one snack per day. Snacks provided 25 % of daily energy from the age of 12 months. Approximately 40 % of toddlers and pre-school children consumed fruit and cow’s milk during snacks; about 25 % consumed 100 % fruit juice. Cookies were introduced early; by 24 months, 57 % consumed cookies or candy in a given day.
Snacking is common, contributing significantly to daily energy and nutrient needs of toddlers and pre-school children. There is room for improvement, however, with many popular snacking choices contributing to excess sugar.