bluuebunny/crossref_metadata_2025_split huggingface dataset:
The secondary instabilities of stationary cross-flow vortices in a Mach 6 swept wing flow
Authors: Xu Guoliang , Chen Jianqiang , Liu Gang , Dong Siwei , Fu Song 
Published: June 2019

The secondary instabilities of stationary cross-flow vortices in a Mach 6 swept wing flow are studied using Floquet theory. High-frequency secondary instability modes of ‘y’ mode on top of stationary cross-flow vortices, and ‘z’ mode concentrating on the shoulder of the stationary cross-flow vortex are found. The most unstable secondary instability mode is always the ‘z’ mode as in incompressible swept wing flows. A new secondary instability mode concentrating on the trough of the stationary cross-flow vortex is found. The balance analysis of disturbance kinetic energy shows that the new mode belongs to the class of ‘y’ mode. The growth rate of the new ‘y’ mode located on the trough of the stationary cross-flow vortex is significantly larger than that of the ‘y’ mode on top of the stationary cross-flow vortex, and is comparable with the growth rate of the ‘z’ mode. It is also found that the new ‘y’ mode with higher frequency can evolve into the ‘z’ mode further downstream. The role of the pressure fluctuation term, including the pressure diffusion and pressure dilatation, in the energy production of secondary instability modes, is also investigated. It is shown that the pressure diffusion will only enhance the growth rate of the ‘z’ mode with higher frequency, but has little influence on other types of secondary instability mode. However, the pressure dilatation term arising from non-vanishing velocity divergence will reduce the growth rates of all secondary instability modes.
Ice scallops: a laboratory investigation of the ice–water interface
Authors: Bushuk Mitchell , Holland David M. , Stanton Timothy P. , Stern Alon , Gray Callum 
Published: June 2019

Ice scallops are a small-scale (5–20 cm) quasi-periodic ripple pattern that occurs at the ice–water interface. Previous work has suggested that scallops form due to a self-reinforcing interaction between an evolving ice-surface geometry, an adjacent turbulent flow field and the resulting differential melt rates that occur along the interface. In this study, we perform a series of laboratory experiments in a refrigerated flume to quantitatively investigate the mechanisms of scallop formation and evolution in high resolution. Using particle image velocimetry, we probe an evolving ice–water boundary layer at sub-millimetre scales and 15 Hz frequency. Our data reveal three distinct regimes of ice–water interface evolution: a transition from flat to scalloped ice; an equilibrium scallop geometry; and an adjusting scallop interface. We find that scalloped-ice geometry produces a clear modification to the ice–water boundary layer, characterized by a time-mean recirculating eddy feature that forms in the scallop trough. Our primary finding is that scallops form due to a self-reinforcing feedback between the ice-interface geometry and shear production of turbulent kinetic energy in the flow interior. The length of this shear production zone is therefore hypothesized to set the scallop wavelength.
Interaction of a downslope gravity current with an internal wave
Authors: Ouillon Raphael , Meiburg Eckart , Ouellette Nicholas T. , Koseff Jeffrey R. 
Published: June 2019

We investigate the interaction of a downslope gravity current with an internal wave propagating along a two-layer density jump. Direct numerical simulations confirm earlier experimental findings of a reduced gravity current mass flux, as well as the partial removal of the gravity current head from its body by large-amplitude waves (Hogg et al., Environ. Fluid Mech., vol. 18 (2), 2018, pp. 383–394). The current is observed to split into an intrusion of diluted fluid that propagates along the interface and a hyperpycnal current that continues to move downslope. The simulations provide detailed quantitative information on the energy budget components and the mixing dynamics of the current–wave interaction, which demonstrates the existence of two distinct parameter regimes. Small-amplitude waves affect the current in a largely transient fashion, so that the post-interaction properties of the current approach those in the absence of a wave. Large-amplitude waves, on the other hand, perform a sufficiently large amount of work on the gravity current fluid so as to modify its properties over the long term. The ‘decapitation’ of the current by large waves, along with the associated formation of an upslope current, enhance both viscous dissipation and irreversible mixing, thereby strongly reducing the available potential energy of the flow.
The gig economy: a hypothetical contract analysis
Authors: Moore Marc T 
Published: June 2019

AbstractGig work and other flexible labour practices have been subject to unprecedented levels of attention recently. While this topic has attracted significant interest from employment lawyers, it remains relatively underexplored from other pertinent legal and inter-disciplinary angles. This paper will adopt an alternative perspective on flexible work inspired by Coase's theory of the firm. Focusing on the implications of flexible work for the relative allocation of control, risk and reward within the firm, it will highlight how both task-oriented (gig) and on-demand (casual) work practices typically entail workers assuming most of the positional disadvantages associated with orthodox employment and self-employment, while enjoying none or few of the corresponding advantages. Using a hypothetical contract analysis, it will highlight the structural similarity between flexible work and unsecured financial investments in business firms by reference to key strands of institutional economics and law and finance literature. On this basis, it will enquire as to optimal forms of compensation that rational flexible workers can (counter-factually) be regarded as bargaining for in the absence of impediments to efficient contracting, and as the price for trading off their traditional employment guarantees.
Late Quaternary vertebrates from the Upper Gunnison Basin, Colorado, and small-mammal community resilience to climate change since the last glacial maximum
Authors: Emslie Steven D. , Meltzer David J. 
Published: June 2019

AbstractThe Upper Gunnison Basin (UGB), Colorado, is a montane region characterized by unusual physiography and topographic isolation. Excavations of three caves in the UGB provide one of the most diverse records of high-elevation late Quaternary vertebrates in North America. The localities, Haystack Cave (2450 m above sea level [m asl]), Cement Creek Cave (2860 m asl), and Signature Cave (3055 m asl), together provide a near-continuous record of vertebrate communities that extends from before the last glacial maximum to the present. These communities largely represent a sagebrush (Artemisiaspp.) steppe-tundra environment that prevailed throughout the UGB in the late Pleistocene. At least five taxa of extinct large mammals disappear from the UGB by the Early Holocene; one small mammal (the short-faced skunkBrachyprotomacf.B.brevimala) also became extinct. The fossil record further indicates that only four small extant mammals (Sorex preblei,Dicrostonyxsp.,Lemmiscus curtatus, andUrocitellus elegans) were extirpated from the UGB by the Early Holocene, in part because of community restructuring and loss of open habitats with expansion of forests to higher elevations. An analysis of taxonomic richness and evenness at Cement Creek Cave indicates high resilience in the small mammal community despite major climate shifts over the past 40,000+ yr.
Chronology and Plant Utilization from the Earliest Walled Settlement in the Hexi Corridor, Northwestern China
Authors: Liu Fengwen , Li Haiming , Cui Yifu , Yang Yishi , Lee Harry F , Ding Detian , Hou Yunguang , Dong Guanghui 
Published: June 2019

ABSTRACTThe development and subsistence strategies adopted in ancient settlements are crucial to the understanding of long-term human–environmental interaction in the past. Here, we reassess the chronology of the ancient walled settlement of Sanjiao in the Hexi Corridor in northwestern China through accelerator mass spectrometry radiocarbon (AMS14C) dating and explore the subsistence of the settlers inside through the identification of carbonized seeds and charcoal. In addition, high-resolution paleoclimate records in the Hexi Corridor and nearby regions are employed to explore the reason for the construction of Sanjiao. Our results show that Sanjiao was built around 828 cal BC and remained inhabited through 384–116 cal BC. This indicates Sanjiao is the earliest known walled settlement in the Hexi Corridor. Ancient people at Sanjiao consumed crops such as barley, broomcorn millet, and foxtail millet, and used wood fromTamarix chinensis,Tamarix,Salix,Picea,Hippophae,Betulaceae, andPoaceaeas fuel. The construction date of Sanjiao correlates with climate deterioration and social upheavals in the Hexi Corridor, potentially suggesting a defensive purpose for the site.
Moral Revolutions: The Politics of Piety in the Ottoman Empire Reimagined
Authors: Shafir Nir 
Published: June 2019

AbstractOver the sixteenth and seventeenth centuries an immense body of morality literature emerged in the Ottoman Empire as part of a widespread turn to piety. This article draws upon the anthropology of Islamic revival and secularism to reassess this literature's importance and propose a new view of the history of political thought in the empire. It does so through a close analysis of a fundamental concept of Ottoman political life: “naṣīḥat,”or “advice.” Historians have used “advice books” to counter the presumption that the Ottoman Empire declined after the sixteenth century, but in doing so they have overlooked the concept's broader meaning as “morally corrective criticism.” I analyze two competing visions ofnaṣīḥatat the turn of the eighteenth century to reveal how the concept was deployed to politically transform the empire by reforming its subjects’ morality. One was a campaign by the chief jurist Feyżullah Efendi to educate every Muslim in the basic tenets of Islam. The other was a wildly popular “advice book” written by the poet Nābī to his son that both explicates a new moral code and declares the empire's government and institutions illegitimate. Both transformed politics by requiring that all subjects be responsible moral, and therefore political, actors. The pietistic turn, I argue, turned domestic spaces into political battlegrounds and ultimately created new, individualistic political subjectivities. This, though, requires challenging functionalist conceptions of the relationship between religion and politics and the secularist inclination among historians to relegate morality to the private sphere.
Hijacked: Piracy and Economies of Protection in the Western Indian Ocean
Authors: Dua Jatin 
Published: June 2019

AbstractFrom 2007–2012, a dramatic upsurge in maritime piracy off the coast of Somalia captivated global attention. Over three hundred merchant vessels and some three thousand seafarers were held hostage with ransom amounts ranging from $200,000 to $10 million being paid to release these ships. Somali piracy operated exclusively on a kidnap-and-ransom model with crew, cargo, and ship held captive until a ransom was secured. Ransom, unlike theft or seizure, requires willing parties and systems of exchange. Ransom economies, therefore, bring together disparate actors and make visible the centrality of protection as a mode of accumulation and jurisdiction. As an analytic, this article proposes an anthropology ofprotectionto undercut divides between legality and illegality, trade and finance, piracy and counter piracy. It argues that protection is key to apprehending processes of mobility and interruption central to global capitalism.
Symptom profiling for infectious intestinal disease (IID): a secondary data analysis of the IID2 study
Authors: Donaldson A. L. , Clough H. E. , O'Brien S. J. , Harris J. P. 
Published: June 2019

Abstract
Less than half of stool samples from people symptomatic with infectious intestinal disease (IID) will identify a causative organism. A secondary data analysis was undertaken to explore whether symptomology alone could be used to make inferences about causative organisms. Data were utilised from the Second Study of Infectious Intestinal Disease in the Community. A total of 844 cases were analysed. Few symptoms differentiated individual pathogens, but grouping pathogens together showed that viral IID was more likely when symptom onset was in winter (odds ratio (OR) 2.08, 95% confidence interval (CI) 1.16–3.75) or spring (OR 1.92, 95% CI 1.11–3.33), the patient was aged under 5 years (OR 3.63, 95% CI 2.24–6.03) and there was loss of appetite (OR 2.19, 95% CI 1.29–3.72). The odds of bacterial IID were higher with diarrhoea in the absence of vomiting (OR 3.54, 95% CI 2.37–5.32), diarrhoea which persisted for >3 days (OR 2.69, 95% CI 1.82–3.99), bloody diarrhoea (OR 4.17, 95% CI 1.63–11.83) and fever (OR 1.67, 95% CI 1.11–2.53). Symptom profiles could be of value to help guide clinicians and public health professionals in the management of IID, in the absence of microbiological confirmation.
Is it worth it to cryopreserve embryos with blastulation delay at day 5?
Authors: Montjean D. , Pauly V. , Gervoise-Boyer M. , Amar-Hoffet Aurélie , Geoffroy-Siraudin C. , Boyer P 
Published: June 2019

SummaryThis is a retrospective study over a 5-year period. In total, 3139 embryos were individually cryopreserved (Cryotop®) and warmed using the Kitazato vitrification/warming kit. They were classified into three categories based on their expansion degree. Transfer, implantation and pregnancy rates were assessed for each embryo category and compared using SPSS (Statistical Package for the Social Sciences) software. In total, 1139 couples enrolled in infertility treatment programme benefitted from embryo vitrification at day 5. After warming, embryos belonging to the three categories showed similar success rates. Although there was a trend towards better outcomes when grade 3 embryos were transferred, the differences did not reach statistical significance: implantation rates (n fetal sac/n embryo transferred) grade 1: 21.9%, grade 2: 22.7% and grade 3: 30.3% (=0.19). Pregnancy rate (n clinical pregnancy/n transfer) (21.9%, 22.7%, 30.3%, respectively; P=0.11). Miscarriage rate was not statistically different in the three categories (14.5%, 20.4%, 20%, respectively, P=0.51). Our overall results show that it is worth vitrifying slow kinetics embryos as they provide a non-negligible chance to give rise to a pregnancy.
Contextual factors influencing the implementation of innovations in community-based primary health care: the experience of 12 Canadian research teams
Authors: Ploeg Jenny , Wong Sabrina T. , Hassani Kasra , Yous Marie-Lee , Fortin Martin , Kendall Claire , Liddy Clare , Markle-Reid Maureen , Petrovic Bojana , Dionne Emilie , Scott Cathie M. , Wodchis Walter P. 
Published: June 2019

Abstract
The objectives of this paper are to: (1) identify contextual factors such as policy that impacted the implementation of community-based primary health care (CBPHC) innovations among 12 Canadian research teams and (2) describe strategies used by the teams to address contextual factors influencing implementation of CBPHC innovations. In primary care settings, consideration of contextual factors when implementing change has been recognized as critically important to success. However, contextual factors are rarely recorded, analyzed or considered when implementing change. The lack of consideration of contextual factors has negative implications not only for successfully implementing primary health care (PHC) innovations, but also for their sustainability and scalability. For this evaluation, data collection was conducted using self-administered questionnaires and follow-up telephone interviews with team representatives. We used a combination of directed and conventional content analysis approaches to analyze the questionnaire and interview data. Representatives from all 12 teams completed the questionnaire and 11 teams participated in the interviews; 40 individuals participated in this evaluation. Four themes representing contextual factors that impacted the implementation of CBPHC innovations were identified: (I) diversity of jurisdictions (II) complexity of interactions and collaborations (III) policy, and (IV) the multifaceted nature of PHC. The teams used six strategies to address these contextual factors including: (1) conduct an environmental scan at the beginning (2) maintaining engagement among partners and stakeholders by encouraging open and inclusive communication; (3) contextualizing the innovation for different settings; (4) anticipating and addressing changes, delays, and the need for additional resources; (5) fostering a culture of research and innovation among partners and stakeholders; and (6) ensuring information about the innovation is widely available. Implementing CBPHC innovations across jurisdictions is complex and involves navigating through multiple contextual factors. Awareness of the dynamic nature of context should be considered when implementing innovations.
A neural network extension of the Lee–Carter model to multiple populations
Authors: Richman Ronald , Wüthrich Mario V. 
Published: June 2019

AbstractThe Lee–Carter (LC) model is a basic approach to forecasting mortality rates of a single population. Although extensions of the LC model to forecasting rates for multiple populations have recently been proposed, the structure of these extended models is hard to justify and the models are often difficult to calibrate, relying on customised optimisation schemes. Based on the paradigm of representation learning, we extend the LCmodel to multiple populations using neural networks, which automatically select an optimal model structure. We fit this model to mortality rates since 1950 for all countries in the Human Mortality Database and observe that the out-of-sample forecasting performance of the model is highly competitive.
Influence of weed size on herbicide interactions for Enlist™ and Roundup Ready® Xtend® technologies
Authors: Meyer Chris J. , Norsworthy Jason K. 
Published: June 2019

AbstractWeed size can nfluence herbicide performance and herbicide interactions in mixtures. To control a broad range of species in soybean or cotton, POST herbicide mixtures will likely be commonplace in Roundup Ready® XtendFlex® and Enlist™ technologies. The impact of weed size on herbicide interactions that could occur in Roundup Ready XtendFlex or Enlist crops was assessed in two field experiments conducted in 2015 and 2016 at the Northeast Research and Extension Center in Keiser, AR. Combinations of glufosinate, glyphosate, dicamba, and 2,4-D were applied to either 10-cm or 30-cm weeds and evaluated for percent weed control, height reduction, and density reduction, collected 5 wk after treatment. Colby’s method was used to analyze treatments for herbicide interactions for control of barnyardgrass, Palmer amaranth, and pitted morningglory. Antagonism was identified with at least one treatment on all species. Almost all treatments were antagonistic for percent weed control, height reduction, and density reduction on barnyardgrass. When glyphosate in mixture with 2,4-D or dicamba was applied to 30-cm barnyardgrass, control declined 9% for both mixtures relative to glyphosate alone. Glufosinate plus glyphosate was antagonistic when applied to both 30-cm pitted morningglory and barnyardgrass. Glufosinate plus dicamba provided less control and density reduction of Palmer amaranth than what was expected from Colby’s equation. Overall, antagonism was more likely to be identified when applications were made to 30-cm weeds compared with 10-cm weeds. The utility of a given herbicide mixture will depend on the species present in the field and the size of those species at the time of application.
Exploring the Importance of the Mindoro‐Sibutu Pathway to the Upper‐Layer Circulation of the South China Sea and the Indonesian Throughflow
Authors: Li Mingting , Wei Jun , Wang Dongxiao , Gordon Arnold L. , Yang Song , Malanotte‐Rizzoli Paola , Jiang Guoqing 
Published: June 2019

AbstractUsing a high‐resolution (0.1° × 0.1°) regional ocean model, this study investigates the impact of strait transport variability on the South China Sea (SCS) circulation and Indonesian throughflow, with a focus on the Mindoro‐Sibutu pathway via the Sulu Sea, upon closing various straits within the Maritime Continent. Closing the Sibutu Strait reduces the Luzon Strait throughflow into the SCS by 75%, and the Mindoro–Sibutu deep exchange is reversed, thus flowing into the SCS. No significant change occurs over the shallow Sunda Shelf of the southern SCS, which is primarily driven by local monsoon winds. The impact of closing the Karimata Strait is limited to the Sunda Shelf and the Java Sea. The Sibutu Strait throughflow is fundamental in governing the SCS's low salinity, buoyancy, and upper layer injection into the Makassar Strait, which is the primary component of the Indonesian throughflow, thus inhibiting the transport within the upper 200 m of the throughflow. Closing both the Sibutu and Karimata Straits increases the southward Makassar Strait throughflow transport by ~3 Sv, which is derived entirely from the Mindanao Current.
Lithospheric Structure and Evolution of Southern Africa: Constraints From Joint Inversion of Rayleigh Wave Dispersion and Receiver Functions
Authors: Wang Tuo , Gao Stephen S. , Dai Yuhang , Yang Qiuyue , Liu Kelly H. 
Published: June 2019

AbstractWe conduct a joint inversion of teleseismic receiver functions and Rayleigh wave phase velocity dispersion from both ambient noise and earthquakes using data from 79 seismic stations in southern Africa, which is home to some of the world's oldest cratons and orogenic belts. The area has experienced two of the largest igneous activities in the world (the Okavango dyke swarm and Bushveld mafic intrusion) and thus is an ideal locale for investigating continental formation and evolution. The resulting 3‐D shear wave velocities for the depth range of 0–100 km and crustal thickness measurements show a clear spatial correspondence with known geological features observed on the surface. Higher than normal mantle velocities found beneath the southern part of the Kaapvaal craton are consistent with the basalt removal model for the formation of cratonic lithosphere. In contrast, the Bushveld complex situated within the northern part of the craton is characterized by a thicker crust and higher crustalVp/Vsbut lower mantle velocities, which are indicative of crustal underplating of mafic materials and lithospheric refertilization by the world's largest layered mafic igneous intrusion. The thickened crust and relatively low elevation observed in the Limpopo belt, which is a late Archean collisional zone between the Kaapvaal and Zimbabwe cratons, can be explained by eclogitization of the basaltic lower crust. The study also finds evidence for the presence of a stalled segment of oceanic lithosphere beneath the southern margin of the Proterozoic Namaqua‐Natal mobile belt.