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Estimates vary, but it is generally accepted that there are 5,000 to 6,500 languages spoken in the world today (1,900 to 2,500 just in Africa). Over half of the world’s languages will disappear by 2050, however, meaning that over half of the world’s languages are presently endangered (Nettle & Romaine, 2000). By the end of the century it is predicted that over 80 percent of the world’s languages will be gone (Krauss, 1992). Clearly if we want to record languages before they die, let alone encourage their survival through a revitalization program, the work is urgent.
Cigarette smoking is highly prevalent among young people experiencing homelessness, and many of these smokers are motivated to quit. However, there is a lack of readily available cessation services for this population, which is highly mobile and can be challenging to engage in services.
We describe the development of a smoking cessation text messaging intervention (TMI) for homeless youth who are interested in quitting smoking.
Participants were 18–25 years old and recruited from drop-in centers serving homeless youth. Three focus groups (N = 18) were conducted with smokers to refine the TMI content, and a separate sample of smokers (N = 8) provided feedback on the TMI after using it for 1 week. Survey data assessed the TMI's acceptability and feasibility.
Participants generally rated the TMI as helpful and relevant, and nearly all had cell phone plans that included unlimited texting and were able to view TMI content with few difficulties. Qualitative feedback on strengths/limitations of the TMI in terms of content, tone, and delivery parameters was used to finalize the TMI for a future evaluation.
Results suggest that a TMI is a feasible and acceptable option for young people experiencing homelessness who are interested in quitting smoking.
The COllaborative project of Development of Anthropometrical measures in Twins (CODATwins) project is a large international collaborative effort to analyze individual-level phenotype data from twins in multiple cohorts from different environments. The main objective is to study factors that modify genetic and environmental variation of height, body mass index (BMI, kg/m2) and size at birth, and additionally to address other research questions such as long-term consequences of birth size. The project started in 2013 and is open to all twin projects in the world having height and weight measures on twins with information on zygosity. Thus far, 54 twin projects from 24 countries have provided individual-level data. The CODATwins database includes 489,981 twin individuals (228,635 complete twin pairs). Since many twin cohorts have collected longitudinal data, there is a total of 1,049,785 height and weight observations. For many cohorts, we also have information on birth weight and length, own smoking behavior and own or parental education. We found that the heritability estimates of height and BMI systematically changed from infancy to old age. Remarkably, only minor differences in the heritability estimates were found across cultural–geographic regions, measurement time and birth cohort for height and BMI. In addition to genetic epidemiological studies, we looked at associations of height and BMI with education, birth weight and smoking status. Within-family analyses examined differences within same-sex and opposite-sex dizygotic twins in birth size and later development. The CODATwins project demonstrates the feasibility and value of international collaboration to address gene-by-exposure interactions that require large sample sizes and address the effects of different exposures across time, geographical regions and socioeconomic status.
RANS models remain an attractive turbulence simulation method which could provide some open jet aerofoil interaction analysis at a fraction of the cost of a high-fidelity LES approach. The present work explores the potential and limitations of RANS in this context by simulating an open jet aerofoil noise experiment using the aerospace oriented Menter SST RANS model. This model’s tendency to transition at a critical Reynolds number lower than the experimental value was found to impact the boundary layer development. However, the introduction of a low-Re correction improved the prediction of surface pressure and skin friction, enabling the suction surface separation bubble to be captured. The free shear layer’s virtual origin characteristics exhibited sensitivity to the interaction with the aerofoil, which can be developed into a metric of the interaction. The main challenge for RANS was accounting for the rise in background disturbance level in the working section, which is caused by the high-turbulence intensity in the free shear layers.
Intelligence community (IC) and by extension the American government, Christian missions, Peace Corps and numerous research initiatives form the braid of North American scholarship on African languages. Mainstream North American linguistics continued to be relatively uninterested in Africa until recently. African languages gained importance when they proved relevant to linguistic theory, exhibiting features that caused theoreticians to reformulate their thinking. Interest was further stimulated when funding became available for the documentation of endangered languages. Missionaries have been more constant in their attention, although that work has changed to converge as missionaries, too, focused on literacy, language documentation and linguistic analysis. The study of African languages in Latin America had in focus the Spanish and Portuguese varieties spoken in former European colonies. In Brazil, research on African languages gave first priority to the lexicon and discussed the possibility of the Brazilian Portuguese having undergone a creolization process. In the other countries of Latin America, the situation is similar in the sense that, except the Creole of Colombia, the African presence was considered only to be found in the lexicon, which did not significantly modify the Hispanic varieties of the continent. In addition to the search for grammatical features of African languages in the linguistic varieties spoken in Latin America, there is still a strong interest in the identification of lexical elements mainly of Bantu origin.
A direct numerical simulation (DNS) of a plane wall jet is performed at a Reynolds number of
. The streamwise length of the domain is long enough to achieve self-similarity for the mean flow and the Reynolds shear stress. This is the highest Reynolds number wall jet DNS for a large domain achieved to date. The high resolution simulation reveals the unsteady flow field in great detail and shows the transition process in the outer shear layer and inner boundary layer. Mean flow parameters of maximum velocity decay, wall shear stress, friction coefficient and jet spreading rate are consistent with several other studies reported in the literature. Mean flow, Reynolds normal and shear stress profiles are presented with various scalings, revealing the self-similar behaviour of the wall jet. The Reynolds normal stresses do not show complete similarity for the given Reynolds number and domain length. Previously published inner layer budgets based on LES are inaccurate and those that have been measured are only available in the outer layer. The current DNS provides fully balanced, explicitly calculated budgets for the turbulence kinetic energy, Reynolds normal stresses and Reynolds shear stress in both the inner and outer layers. The budgets are scaled with inner and outer variables. The inner-scaled budgets in the near wall region show great similarity with turbulent boundary layers. The only remarkable difference is for the turbulent diffusion in the wall-normal Reynolds stress and Reynolds shear stress budgets. The outer layer interacts with the inner layer through turbulent diffusion and the excess energy from the wall-normal direction is transferred to the spanwise direction.
The discovery of the first electromagnetic counterpart to a gravitational wave signal has generated follow-up observations by over 50 facilities world-wide, ushering in the new era of multi-messenger astronomy. In this paper, we present follow-up observations of the gravitational wave event GW170817 and its electromagnetic counterpart SSS17a/DLT17ck (IAU label AT2017gfo) by 14 Australian telescopes and partner observatories as part of Australian-based and Australian-led research programs. We report early- to late-time multi-wavelength observations, including optical imaging and spectroscopy, mid-infrared imaging, radio imaging, and searches for fast radio bursts. Our optical spectra reveal that the transient source emission cooled from approximately 6 400 K to 2 100 K over a 7-d period and produced no significant optical emission lines. The spectral profiles, cooling rate, and photometric light curves are consistent with the expected outburst and subsequent processes of a binary neutron star merger. Star formation in the host galaxy probably ceased at least a Gyr ago, although there is evidence for a galaxy merger. Binary pulsars with short (100 Myr) decay times are therefore unlikely progenitors, but pulsars like PSR B1534+12 with its 2.7 Gyr coalescence time could produce such a merger. The displacement (~2.2 kpc) of the binary star system from the centre of the main galaxy is not unusual for stars in the host galaxy or stars originating in the merging galaxy, and therefore any constraints on the kick velocity imparted to the progenitor are poor.
Whether monozygotic (MZ) and dizygotic (DZ) twins differ from each other in a variety of phenotypes is important for genetic twin modeling and for inferences made from twin studies in general. We analyzed whether there were differences in individual, maternal and paternal education between MZ and DZ twins in a large pooled dataset. Information was gathered on individual education for 218,362 adult twins from 27 twin cohorts (53% females; 39% MZ twins), and on maternal and paternal education for 147,315 and 143,056 twins respectively, from 28 twin cohorts (52% females; 38% MZ twins). Together, we had information on individual or parental education from 42 twin cohorts representing 19 countries. The original education classifications were transformed to education years and analyzed using linear regression models. Overall, MZ males had 0.26 (95% CI [0.21, 0.31]) years and MZ females 0.17 (95% CI [0.12, 0.21]) years longer education than DZ twins. The zygosity difference became smaller in more recent birth cohorts for both males and females. Parental education was somewhat longer for fathers of DZ twins in cohorts born in 1990–1999 (0.16 years, 95% CI [0.08, 0.25]) and 2000 or later (0.11 years, 95% CI [0.00, 0.22]), compared with fathers of MZ twins. The results show that the years of both individual and parental education are largely similar in MZ and DZ twins. We suggest that the socio-economic differences between MZ and DZ twins are so small that inferences based upon genetic modeling of twin data are not affected.
This paper will present a dynamic Variable Rate Irrigation System developed by the University of Georgia. The system consists of the EZZone management zone delineation tool, the UGA Smart Sensor Array (UGA SSA) and an irrigation scheduling decision support tool. An experiment was conducted in 2015 and 2016 in two different peanut fields to evaluate the performance of using the UGA SSA to dynamically schedule Variable Rate Irrigation (VRI). For comparison reasons strips were designed within the fields. These strips were irrigated according to either UGA SSA or Irrigator Pro recommendations. The results showed that Irrigator Pro is a conservative irrigation method which results in high yields. On the other hand the UGA SSA recommendations worked very well with the VRI system and in both years it recommended an average of 25% less irrigation water than the Irrigator Pro.
The Dark Energy Survey is undertaking an observational programme imaging 1/4 of the southern hemisphere sky with unprecedented photometric accuracy. In the process of observing millions of faint stars and galaxies to constrain the parameters of the dark energy equation of state, the Dark Energy Survey will obtain pre-discovery images of the regions surrounding an estimated 100 gamma-ray bursts over 5 yr. Once gamma-ray bursts are detected by, e.g., the Swift satellite, the DES data will be extremely useful for follow-up observations by the transient astronomy community. We describe a recently-commissioned suite of software that listens continuously for automated notices of gamma-ray burst activity, collates information from archival DES data, and disseminates relevant data products back to the community in near-real-time. Of particular importance are the opportunities that non-public DES data provide for relative photometry of the optical counterparts of gamma-ray bursts, as well as for identifying key characteristics (e.g., photometric redshifts) of potential gamma-ray burst host galaxies. We provide the functional details of the DESAlert software, and its data products, and we show sample results from the application of DESAlert to numerous previously detected gamma-ray bursts, including the possible identification of several heretofore unknown gamma-ray burst hosts.
As for the future, your task is not to foresee it, but to enable it
– Antoine de Saint-Exupery, French pilot and writer
Slotnick et al. (2014) note that in 2025 air transport will contribute 1.5 billion tonnes of CO2 emissions annually. The aerospace industry has largely given rise to the inception of computational fluid dynamics and much of its subsequent development. It seems likely, that with modern CFD developments, it will play a paramount role in continuing to help alleviate the environmental impact of aircraft. In aerospace, CFD originally would focus on studying basic airfoils. However, nowadays it has gone well beyond this. To meet the modern multi-objective, multi-scale, coupled industrial requirements, CFD has become a highly multi-disciplinary subject area. It is hoped that this aspect has come across in the preceding text.
Figure 8.1 shows the growth of computers. The dotted line shows the growth with year of the number one fastest computer. The full line gives the 500th fastest. The dashed line gives the growth in the use of LES in an applied, industrial turbomachinery journal – the ASME Journal of Turbomachinery. There is a clear trend in the growth in the use of eddy-resolving simulations with increased computing power. Clearly the industrial use of eddy-resolving simulations will lag this more academic use. However, as noted by Lele and Nichols (2014), for non-wall bounded flows, eddy-resolving simulations could be used in industry in the next five to ten years. Indeed there is some current use for specific circumstances. Also, notably, Morton et al. (2007) performed eddy-resolving simulations for F/A–18 fighter configuration. Tail buffet compared well with real flight spectral data.
In this chapter, it is explored how CFD will look in the next decade and beyond. Much of these ideas are based on the contributions to the Royal Society Theme issue of Tucker and DeBonis (2014).
Computer Science and Computers
As can be seen from Figure 8.1, there is healthy growth in computing power. As noted by Jameson (2008), in the past twenty-five years, computers have become a million times faster. However, algorithmic improvements are needed that are customized for high-performance computers. It is quite power intensive to move data around in memory.
The age of chivalry has gone. That of…calculator's has succeeded and the glory of Europe is extinguished forever.
E. Burke (1972)
According to Slotnick et al. (2014), in 2025, air transport will contribute 1.5 billion tonnes of CO2 emissions annually. Of course, there are many other fluid dynamic engineering systems and processes that contribute to environmentally damaging emissions. Hence, it is critical to study aerodynamics with the view to creating more energy-efficient systems.
Broadly speaking, the design engineer has the following three options for informing decisions regarding aerodynamics:
• Analytical solutions
• Computer simulations
Computational Fluid Dynamics
Since its inception around the 1960s, computer based simulation has revolutionised fluid mechanics. The key area of computer simulation in fluid mechanics is called Computational Fluid Dynamics (CFD). It is generally taken as involving the solution of the full equations governing conservation of mass, momentum and energy in a fluid, with generally little simplification to these equations. Currently, mostly it is still best for a company to take advantage of all three of the above techniques. The development of CFD has been most strongly driven by the aerospace industry. CFD's name has sometimes been partly tarnished, with suggestions that the acronym should be standing for ‘Cheats Frauds and Deceivers’ or ‘Colourful Fluid Dynamics’. As with any experimental method, the use of CFD often requires extreme skill. CFD codes cannot be run by engineers (focused on extremely complex multidisciplinary design tasks) lacking some specialist training and without clear guidance. The modelling of turbulence has limited the accuracy of CFD, rendering the need for comparisons with test data (validation). The uncertainty in modelling turbulence has made CFD almost a postdictive method. However, with the power of modern computers, eddy-resolving techniques (the nearly exact flow equations solved to high accuracy) are beginning to emerge. Hence, we are beginning to move into a predictive era of CFD. In the future, the way in which CFD is used is likely to change substantially.
Generally with CFD simulations, the fluid flow field is divided into numerous small cells. Processes for carrying this out are described in Chapter 3. The flow-governing equations, described in Chapter 2, are solved locally for each of these cells. The solution process ensures mass, momentum and energy conservation between the cells.
The advent of supercomputers has brought computational fluid dynamics (CFD) to the forefront as a tool to analyze increasingly complex simulation scenarios in many fields. Computational aerodynamics problems are also increasingly moving towards being coupled, multi-physics and multi-scale with complex, moving geometries. The latter presents severe geometry handling and meshing challenges. Simulations also frequently use formal design optimization processes. This book explains the evolution of CFD and provides a comprehensive overview of the plethora of tools and methods available for solving complex scenarios while exploring the future directions and possible outcomes. Using numerous examples, illustrations and computational methods the author discusses turbulence modeling, pre and post processing, coupled solutions, the importance of design optimization, multiphysics problems, reduced order models, and large scale computations and the future of CFD. Advanced Computational Fluid and Aerodynamics is suitable for audiences engaged in computational fluid dynamics including advanced undergraduates, researchers and industrial practitioners.