bluuebunny/crossref_metadata_2025_split huggingface dataset:
Extremely Low‐Frequency Waves Inside the Diamagnetic Cavity of Comet 67P/Churyumov‐Gerasimenko
Authors: Madsen B. , Wedlund C. Simon , Eriksson A. , Goetz C. , Karlsson T. , Gunell H. , Spicher A. , Henri P. , Vallières X. , Miloch W. J. 
Published: May 2018

AbstractThe European Space Agency/Rosetta mission to comet 67P/Churyumov‐Gerasimenko has provided several hundred observations of the cometary diamagnetic cavity induced by the interaction between outgassed cometary particles, cometary ions, and the solar wind magnetic field. Here we present the first electric field measurements of four preperihelion and postperihelion cavity crossings on 28 May 2015 and 17 February 2016, using the dual‐probe electric field mode of the Langmuir probe (LAP) instrument of the Rosetta Plasma Consortium. We find that on large scales, variations in the electric field fluctuations capture the cavity and boundary regions observed in the already well‐studied magnetic field, suggesting the electric field mode of the LAP instrument as a reliable tool to image cavity crossings. In addition, the LAP electric field mode unravels for the first time extremely low‐frequency waves within two cavities. These low‐frequency electrostatic waves are likely triggered by lower‐hybrid waves observed in the surrounding magnetized plasma.
Electrical Resistivity of Fe‐C Alloy at High Pressure: Effects of Carbon as a Light Element on the Thermal Conductivity of the Earth's Core
Authors: Zhang Chengwei , Lin Jung‐Fu , Liu Ying , Feng Shaomin , Jin Changqing , Hou Mingqiang , Yoshino Takashi 
Published: May 2018

AbstractWe measured the electrical resistivity of iron, Fe99C1, Fe3C, and Fe7C3 up to ~80 GPa using the van der Pauw method in a diamond anvil cell. The electrical resistivity of disordered Fe99C1 at high pressure shows a strong impurity resistivity of carbon. The ferromagnetic‐paramagnetic transition in Fe3C and Fe7C3 is associated with the flattening of the resistivity pressure gradient at ~6 GPa. Fe7C3 exhibits the highest electrical resistivity among all iron‐light element alloys, and Fe3C and Fe7C3 disobey the Matthiessen's rule by showing a lower electrical resistivity than a disordered iron‐carbon alloy because of chemical ordering. A comparison of the impurity resistivity between silicon, sulfur, nickel, and carbon shows that carbon has an exceedingly stronger alloying effect than other elements. If the chemical ordering observed in Fe‐Si system is held true for the Fe‐C system, the chemical ordering in Fe7C3 possibly increases the thermal conductivity of the inner core and enlarges the thermal and electrical conductivity gap at the inner‐core boundary. Models of the thermal conductivity of liquid Fe70C30 with 8.4 wt % carbon show a low thermal conductivity of 38 Wm−1 K−1 at the pressure‐temperature conditions of the topmost outer core. The corresponding heat flow of 6 TW at the core‐mantle boundary is notably lower than previous electrical resistivity results on Fe and Fe alloys. The alloying effect of carbon on the electrical and thermal conductivity of iron can thus play a significant role in understanding the heat flux at the core‐mantle boundary and the thermal evolution of the core.
Lake‐Atmosphere Heat Flux Dynamics of a Thermokarst Lake in Arctic Siberia
Authors: Franz D. , Mammarella I. , Boike J. , Kirillin G. , Vesala T. , Bornemann N. , Larmanou E. , Langer M. , Sachs T. 
Published: May 2018

AbstractWe conducted eddy covariance measurements from April to August 2014 on a Siberian thermokarst lake. The study site is located in the Lena River Delta and characterized as a floating ice lake. Heat fluxes differed in magnitudes, directions and temporal patterns depending on the lake surface conditions (“frozen” ice cover, ice cover melt, and open water). Significant heat release during frozen ice cover conditions highlighted the importance of lakes for the landscape heat budget and water balance. The energy balance was nearly closed during the open water period and highlighted the impact of melting energy on its closure during the ice cover period. Sensible and latent heat dynamics were driven by temperature and water vapor gradients scaled by wind speed, respectively. We calculated bulk aerodynamics transfer coefficients and evaluated the performance of the derived in situ and three independent heat flux parameterization schemes. We found that bulk transfer models perform moderately to poorly for the different lake surface conditions. During the open water period small‐scale temporal variability could not be represented by the models, particularly in case of latent heat flux. The model results were less sensitive to the specific model type than to the accuracy of the surface water temperature measurement, which is dependent on a well‐thought‐out measurement design. Our study stresses considerations that are crucial for similar campaigns in the future, in order to face the measurement challenges encountered on arctic lakes especially during the ice cover period.
Sensitivity of Radiative‐Convection Equilibrium to Divergence Damping in GFDL‐FV3‐Based Cloud‐Resolving Model Simulations
Authors: Anber Usama M. , Jeevanjee Nadir , Harris Lucas M. , Held Isaac M. 
Published: May 2018

AbstractUsing a nonhydrostatic model based on a version of Geophysical Fluid Dynamics Laboratory's FV3 dynamical core at a cloud‐resolving resolution in radiative‐convective equilibrium (RCE) configuration, the sensitivity of the mean RCE climate to the magnitude and scale‐selectivity of the divergence damping is explored. Divergence damping is used to reduce small‐scale noise in more realistic configurations of this model. This sensitivity is tied to the strength (and width) of the convective updrafts, which decreases (increases) with increased damping and acts to organize the convection, dramatically drying out the troposphere and increasing the outgoing longwave radiation. Increased damping also results in a much‐broadened precipitation probability distribution and larger extreme values, as well as reduction in cloud fraction, which correspondingly decreases the magnitude of shortwave and longwave cloud radiative effects. Solutions exhibit a monotonic dependence on the strength of the damping and asymptotically converge to the inviscid limit. While the potential dependence of RCE simulations on resolution and microphysical assumptions are generally appreciated, these results highlight the potential significance of the choice of subgrid numerical diffusion in the dynamical core.
The Impact of Vertical Mixing Biases in Large‐Eddy Simulation on Nocturnal Low Clouds
Authors: van Stratum B. J. H. , Stevens B. 
Published: May 2018

AbstractThe use of large‐eddy simulation at a resolution insufficient to resolve the largest turbulent eddies frequently suffers from an overestimation of vertical mixing in the nocturnal boundary layer. The resulting biases in the mean thermodynamic structure—typically an overestimation of the near‐surface temperature, and underestimation of the boundary layer top temperature—could potentially influence the formation of low clouds or fog. Whether this is likely to happen is assessed using both observations, and a newly developed conceptual model. First, observations from Northwestern Europe (Germany and Netherlands) are used to characterize the humidity conditions at night. The results indicate that saturation most likely occurs at the surface, but that the conditions at 200 m height are also often close to saturation. Second, the conceptual model is used to study whether overestimating vertical mixing, and the resulting negative temperature biases at the boundary layer top, could result in a spurious formation of low clouds in large‐eddy simulations. The results convincingly indicate that this is unlikely to happen, as overestimating vertical mixing decreases the relative humidity throughout the nocturnal boundary layer.
Constitutive Law for Earthquake Production Based on Rate‐and‐State Friction: Dieterich 1994 Revisited
Authors: Heimisson Elias R. , Segall Paul 
Published: May 2018

AbstractDieterich (1994, https://doi.org/10.1029/93JB02581) derived a constitutive law for earthquake production based on rate‐and‐state friction, which has since been applied widely to earthquake triggering in various tectonic settings. Here this influential work is revisited and rederived in a more straightforward manner. Our derivation is based on computing the time to instability for a population of sources, and eschews the seismicity state variable. We demonstrate the validity of the Dieterich (1994) model for arbitrary shear stressing history at constant normal stress; however, our results differ slightly if fault normal stress changes with time. We provide simple integral expressions for the cumulative number of events and seismicity rate for arbitrary stressing history. These expressions have no explicit dependence on the time derivative of the stressing history. The simpler derivation makes it easier to assess and generalize various model assumptions in the original formulation. A principal success of the Dieterich (1994) theory is that it predicts and gives physical meaning to the Omori decay of seismicity rate following a stress step. We analyze the assumption that sources are well above steady state and find that Omori decay is produced by sources that either start or end up above steady state following the stress step. If no sources are brought above steady state by the perturbation then the time to reach steady state must be considered, and there will be no Omori sequence.
The Impact of Surface Heterogeneities and Land‐Atmosphere Interactions on Shallow Clouds Over ARM SGP Site
Authors: Xiao Heng , Berg Larry K. , Huang Maoyi 
Published: May 2018

AbstractContinental shallow clouds are an important component of the land‐atmosphere coupled climate system because of their role in modulating energy and water budgets. The parameterization of these clouds in climate models presents a significant challenge. We evaluate the potential impact of subgrid‐scale (for climate models) land‐atmosphere interactions on shallow clouds using nested large‐eddy simulations (LESs). We compare LESs that allow for land‐atmosphere interactions to ones that artificially suppress all or part of them by smoothing out surface heterogeneities in surface heat, moisture and radiation fluxes within the domain. The LES domains are coupled to an interactive land surface model and nested inside a mesoscale domain. Three summertime shallow convection cases over the Department of Energy Atmospheric Radiation Measurement Facility's Southern Great Plains site are examined. A consistent increase in cloud water content is observed in all cases when surface heterogeneities and the land‐atmosphere interactions they induce in the LES domain are removed. By comparing experiments where only surface flux heterogeneities induced by cloud shadows are removed to ones where all surface flux heterogeneities are removed, we find that cloud shading‐induced surface heterogeneities can have a larger impact on shallow convection than static land surface heterogeneities in our cases. Furthermore, the impact of cloud shading on cloud water content and cloud size is found to vary significantly with the solar incidence angle. Our results suggest that the impact of cloud shadows needs to be considered when parameterizing land‐atmosphere interactions in the presence of shallow clouds for regional or global climate models.
Time‐domain approach for LFM signal parameter estimation based on FPGA
Authors: Zhang Peng , Wang Ping , Cheng Julian 
Published: May 2018

An FPGA‐based parameter estimation method for linear frequency modulation (LFM) signal is proposed. The average frequency value of basic time slice is obtained by using improved time‐domain counting method. Then, frequency values are used for the least‐squares fitting, so as to obtain the sweep rate of LFM signal. Compared to estimation methods based on digital signal processing, the proposed approach can effectively reduce the estimation time. Experimental results show that the slope fitting accuracy of mono‐component LFM signal is better than 99.8% and the processing time is <250 ns.
Variety of Enriching Early-Life Activities Linked to Late-Life Cognitive Functioning in Urban Community-Dwelling African Americans
Authors: Chan Thomas , Parisi Jeanine M , Moored Kyle D , Carlson Michelle C 
Published: May 2018

AbstractObjectivesThe early environment is thought to be a critical period in understanding the cognitive health disparities African Americans face today. Much is known about the positive role enriching environments have in mid- and late-life and the negative function adverse experiences have in childhood; however, little is known about the relationship between enriching childhood experiences and late-life cognition. The current study examines the link between a variety of enriching early-life activities and late-life cognitive functioning in a sample of sociodemographic at-risk older adults.MethodThis study used data from African Americans from the Brain and Health Substudy of the Baltimore Experience Corps Trial (M = 67.2, SD = 5.9; N = 93). Participants completed a battery of neuropsychological assessments and a seven-item retrospective inventory of enriching activities before age 13.ResultsFindings revealed that a greater enriching early-life activity score was linked to favorable outcomes in educational attainment, processing speed, and executive functioning.DiscussionResults provide promising evidence that enriching early environments are associated with late-life educational and cognitive outcomes. Findings support the cognitive reserve and engagement frameworks, and have implications to extend life-span prevention approaches when tackling age-related cognitive declines, diseases, and health disparities.
Reappraising the Efficacy and Acceptability of Multicomponent Interventions for Caregiver Depression in Dementia: The Utility of Network Meta-Analysis
Authors: Liew Tau Ming , Lee Cia Sin 
Published: May 2018

AbstractBackgroundPrevious meta-analyses have demonstrated the efficacy of interventions for caregiver depression in dementia. However, they generally lumped the interventions together without accounting for the multicomponent nature of most interventions. It is unknown which combination of components contributed to the efficacy and should be implemented in clinical practice.ObjectivesTo reappraise the interventions for caregiver depression from a recent systematic review, and evaluate whether a network meta-analytic approach offers additional insight into the efficacy and acceptability of multicomponent interventions.Research Design and MethodsThis study built upon a recent systematic review which identified 33 RCTs on caregiver depression from multiple databases (Medline, EMBASE, CENTRAL, PsycINFO, PSYNDEX). The 33 RCTs had different combinations of components serving at least one of the three key functions: addressing the care needs of persons with dementia (“CN”), addressing caregiving competency (“CC”), and providing emotional support for loss and grief (“ES”). A Bayesian network meta-analysis was conducted to compare the efficacy and all-cause attrition across different combinations of interventions.ResultsCN–CC combination was significantly more efficacious than treatment-as-usual (standardized mean difference in depression scores, SMD = −0.25, 95% credible interval [CrI] = −0.41 to −0.08) and marginally better than CN (SMD = −0.43, 95% CrI = −0.85 to −0.00). While none of the interventions clearly had both high efficacy and acceptability, three combinations of interventions (CC, CN–CC, and CN–CC–ES) had a reasonable balance between efficacy and acceptability.Discussion and ImplicationsAlthough interventions for caregiver depression in dementia are effective in general, the different components of interventions may not share the same efficacy and acceptability. In implementing interventions, policymakers may consider addressing CC first, introducing CN in a graded manner, and providing ES only when indicated. Future studies may also consider using network meta-analysis to gain additional insights on how to implement multicomponent interventions in geriatric care.
Sustainable development goals for health promotion: a critical frame analysis
Authors: Spencer Grace , Corbin J Hope , Miedema Esther 
Published: May 2018

Abstract
The Sustainable Development Goals (SDGs) lay the foundations for supporting global health and international development work for the next 15 years. Thirty years ago, the Ottawa Charter defined health promotion and outlined key principles for global action on health, including the importance of advocating, enabling and mediating for health equity. Advocacy underscores a human right to health and suggests political action to support its attainment. Enabling speaks to health promotion’s focus on the empowerment of people and communities to take control over their health and aspirations. Mediation draws attention to the critical intersectoral partnerships required to address health and social inequities. Underpinned by this approach, the aim of this paper is to consider how key health promotion principles, namely, rights, empowerment and partnership feature (and are framed) within the SDGs and to consider how these framings may shape future directions for health promotion. To that end, a critical frame analysis of the Transforming Our World document was conducted. The analysis interrogated varying uses and meanings of partnerships, empowerment and rights (and their connections) within the SDGs. The analysis here presents three framings from the SDGs: (1) a moral code for global action on (in)equity; (2) a future orientation to address global issues yet devoid of history; and (3) a reductionist framing of health as the absence of disease. These framings raise important questions about the underpinning values of the SDGs and pathways to health equity – offering both challenges and opportunities for defining the nature and scope of health promotion.
From Mini to Maxi Jobs? Low Pay, ‘Progression’, and the Duty to Work (Harder)
Authors: Puttick Keith 
Published: May 2018

Abstract
The scale of low pay and in-work poverty affecting the bottom three deciles of the labour market highlights the weaknesses in the two main mechanisms for assisting the low-paid: the statutory minimum wage provided for by the National Minimum Wage Act 1998 and State in-work benefits, particularly Universal Credit (UC) as it operates under the Welfare Reform Act 2012 and Universal Credit Regulations 2013. Both mechanisms are failing badly. The paper argues for new approaches. On the Labour side of what may be called the Labour Law–Social Security Law interface these include reconstruction of the national minimum wage scheme in the 1998 Act so that there are two minimum wage floors: a primary floor based on the current national scheme; and a higher, secondary floor at sectoral level. Sectoral wage-setting, informed by support from a Low Pay Commission with an extended remit, could in time pave the way to wider-ranging, regulated sectoral collective bargaining and systems which align more closely and efficiently to what employers can afford, and relieve the growing fiscal pressures on in-work social security. On the Social Security side, remedial work on UC is urgently needed, particularly on the work allowances which set the earnings thresholds at which in-work State support starts to be withdrawn. If mandatory ‘progression’ requirements under the in-work progression (IWP) scheme are to continue—which is likely given the government’s concern that, without this, workers in low hours, low paid mini jobs will opt to stay parked in such highly subsidised work—then exemptions and protections need to be strengthened and put on a statutory footing (particularly for workers with family responsibilities). Introducing what would, in effect, be a ‘right not to work’ in prescribed cases—typically when requirements impact disproportionately on workers and their family members—would go some way to establishing the necessary safeguards. Clearly, both low pay mechanisms face a crisis of growing proportions: a crisis of coverage as dependence grows and newer groups look to the State for support; a fiscal crisis as costs rise and cuts to support impact on its effectiveness; and a political crisis as support for UC and the wider low pay regime erodes.
Rethinking the shortage of primary care physicians
Authors: Hackey Robert B. , Grasso Victoria , LaRochelle Madeleine , Seaver Katelyn 
Published: May 2018

ABSTRACT
For decades, public concerns about a shortage of physicians led federal and state policy makers to pursue policies to increase the number of medical graduates. In response, the number of medical schools increased dramatically over the past decade. By 2016, the United States produced more new physicians than ever before. Expanding medical school enrollments, however, were not matched by a corresponding increase in the number of physicians choosing primary care. To date, few policy makers questioned the conventional wisdom that more is better when it comes to the supply of primary care physicians. Instead, policy makers should consider alternative approaches to increase access to patient-centered primary care.
Improved Diagnosis and Treatment of Bone and Joint Infections Using an Evidence-based Treatment Guideline
Authors: Quick Rachel D. , Williams John , Fernandez Marisol , Gottschalk Hilton , Cosgrove Peter , Kahlden Kyle , Merkel Kathryn , Thoreson Lynn , Boswell Patrick , Hauger Sarmistha B. 
Published: May 2018

Background:
Our institution created a multidisciplinary guideline for treatment of acute hematogenous osteomyelitis (AHO) and septic arthritis (SA) in response to updates in evidence-based literature in the field and existing provider variability in treatment. This guideline aims to improve the care of these patients by standardizing diagnosis and treatment and incorporating up to date evidence-based research into practice. The primary objective of this study is to compare cases before versus after the implementation of the guideline to determine concrete effects the guideline has had in the care of patients with AHO and SA.

Methods:
This is an Institutional Review Board-approved retrospective study of pediatric patients age 6 months to 18 years hospitalized between January 2009 and July 2016 with a diagnosis of AHO or SA qualifying for the guideline. Cohorts were categorized: preguideline and postguideline. Exclusion criteria consisted of: symptoms >14 days, multifocal involvement, hemodynamic instability, sepsis, or history of immune deficiency or chronic systemic disease. Cohorts were compared for outcomes that described clinical course.

Results:
Data were included for 117 cases that qualified for the guideline: 54 preguideline and 63 postguideline. Following the successful implementation of the guideline, we found significant decrease in the length of intravenous antibiotic treatment (P<0.001), decrease in peripherally inserted central catheter use (P<0.001), and an increase in bacterial identification (P=0.040). Bacterial identification allowed for targeted antibiotic therapy. There was no change in length of hospital stay or readmission rate after the implementation of the guideline.

Conclusion:
Utilizing an evidence-based treatment guideline for pediatric acute hematogenous bone and joint infections can lead to improved bacterial diagnosis and decreased burden of treatment through early oral antibiotic use.

Level of Evidence:
Level III– retrospective comparative study.