bluuebunny/crossref_metadata_2025 huggingface dataset:
An Interprofessional Collaborative Practice Model: Primary-Care Clinical Associates at the Family Practice Setting
Authors: Moe Jessica S.E. , Bailey Allan L. , Kroeker Stanley , Moe Grace
Published: December 2010

A persistent physician shortage challenges the ability of our healthcare system to meet the growing health needs of our aging population. Health system redesign must maximize the efficient use of available human resources. The Alberta Westview Primary Care Network (WPCN) introduced the Primary Care Clinical Associate (CA) program in 2005. This interprofessional collaborative practice model recruits nonphysician health professionals from various disciplines as autonomous, independent practitioners. They are associates of the family physician and use their full scope of practice to jointly care for a panel of patients in family practice settings. Three years after its inception, the CA program has grown steadily from two initial participating family practices to its current implementation in six of seven WPCN clinics. The present direction of Canadian primary healthcare reform is towards team approaches. Accordingly, the CA program has wide applicability provincially across Canada. The objective of this article is to describe in detail the design of the WPCN CA program including its conceptual framework and operational strategies and to share program implementation learning. This knowledge transfer will enable replication of the WPCN CA model, where appropriate, in other jurisdictions.
A Study of the Effectiveness of Performance-Focused Methodology for Improved Outcomes in Alberta Public Healthcare
Authors: Werle Jason , Dobbelsteyn Loretta , Feasel A. Lynn , Hancock Brooke , Job Becky , Makar Linda , Manning Heather , Quigley Sarah , Teppler Art , Smith Christopher , Kelly Sheila , Wasylak Tracy
Published: December 2010

This study evaluates the effectiveness of a performance-focused methodology for engaging multidisciplinary, frontline healthcare teams in making behavioural changes that improve patient care and health system efficiency. Results include significant declines in average length of stay in hospital and waiting time for surgery, and a dramatic increase in early patient ambulation. Performance-focused methodology using key performance indicators, targets, measurement, and ongoing feedback, supported by non-monetary incentives, can quickly improve healthcare outcomes.
Getting the Right Information to the Table: Using Technology to Support Evidence-Based Decision Making
Authors: Atack Lynda , Gignac Patrick , Anderson Malcolm
Published: December 2010

Healthcare executives report that it is difficult to access the research literature and once found, it is frequently not relevant. A study was conducted to explore ways in which healthcare executives, enrolled in the EXTRA program, used a virtual desktop environment. Despite some design and function limitations, the desktop was perceived positively by most participants and was effective in supporting evidence-informed practice and decision making.
Lean service operations: Reflections and new directions for capacity expansion in outpatient clinics
Authors: LaGanga Linda R.
Published: December 2010

This field research in outpatient service operations examines original quantitative data on appointments and analyzes a lean process improvement project that was conducted to increase capacity to admit new patients into a healthcare service operation system. Analysis of 1726 intake appointments for the year preceding and the full year following the lean project showed a 27% increase in service capacity to intake new patients and a 12% reduction in the no‐show rate as a result of the transformation of service processes achieved by the lean project. This study's action research methodology leverages the researcher's involvement in redesigning a service system that greatly improved performance and led to reflection on traditional operations management (OM) approaches to appointment scheduling. The study generates insights about effective alignment of resources, develops new strategies for service operations to respond to no‐shows, reveals time‐related variables that have been overlooked in appointment scheduling research, and challenges traditional OM scheduling performance measures. We provide recommendations for effective and appropriate use of overbooking and identify avenues for future research to continuously improve and increase the capacity of service operations.
II Landscape and Aesthetics
Authors: Spencer Diana
Published: December 2010

Defining a space as landscape suggests that it is visually distinctive and interesting, that it attracts the eye, and engages the senses and faculties. Agriculture (or productivity) can be one important feature of what makes space into land and divides it up into -scapes and territories, but it is not always the main issue. Typically, classical texts featuring something akin to our ‘landscape’ showcase the natural environment supporting, threatening, or ornamenting human existence. So at the beginning of the Graeco–Roman tradition we see that the landscapes of Homeric epic, or pastoral verse (for example, the Hellenistic poets Bion and Theocritus), gain order and meaning from the inclusion of human figures, but they also contribute atmosphere and a distinctive sense of place that enriches the stories that play out against them. Chapter I introduced one particularly delightful and hugely popular topographic trope: an idyllic space where sensory and aesthetic qualities encourage harmony between humans and nature. The locus classicus or touchstone for this locus amoenus is Plato's dialogue Phaedrus. Famously, this dialogue riffs on a very specific landscape scene, one which was to have an intense and far-reaching effect on subsequent landscape discourse, and which provides an ideal point of departure.
V Italy and the Villa Estate, or, of Cabbages and Kings
Authors: Spencer Diana
Published: December 2010

Luxury villas and working farms are crucial to Roman interest in what constitutes landscape, and they form the backdrop for this Survey's final two chapters. By the mid-first century BCE, lavishly designed and decorated villas represented not just a source of revenue qualifying their wealthy and educated owners for entering public life, but also an alternative performance venue to the traditional urban sites for political debate – Senate and Forum. Relationship with and management of land became a way of ‘defining what it meant to be a member of the Roman elite, in excluding outsiders from this powerful and privileged group and in controlling insiders.
IS HEALTH STATUS OF ELDERLY WORSENING IN INDIA? A COMPARISON OF SUCCESSIVE ROUNDS OF NATIONAL SAMPLE SURVEY DATA
Authors: HUSAIN ZAKIR , GHOSH SASWATA
Published: December 2010

The increasing greying of India's population raises concerns about the welfare and health status of the aged. One important source of information of health status of the elderly is the National Sample Survey Rounds on Morbidity and Health Care Expenditure. Using unit-level data for 1995–96 and 2004, this paper examines changes in reported health status of the elderly in India and analyses their relationship with living arrangements and extent of economic dependency. It appears that even after controlling for factors like caste, education, age, economic status and place of residence, there has been a deterioration in self-perceived current health status of the elderly. The paper argues that, although there have been changes in the economic condition and traditional living arrangements – with a decline in co-residential arrangements – this is not enough to explain the decline in reported health status and calls for a closer look at narratives of neglect being voiced in developing countries.
Settlement and recruitment of the crab Halicarcinus planatus (Crustacea: Decapoda: Hymenosomatidae) in Golfo San Jorge, Argentina
Authors: Vinuesa Julio H. , Varisco Martín , Escriche Florencia
Published: December 2010

The settlement and recruitment of the small brachyuran crab Halicarcinus planatus from the central area of Golfo San Jorge, south-western Atlantic Ocean, was studied. Three different artificial collectors were evaluated: smooth-surface panels, panels covered with synthetic lawn and ballasted plastic boxes filled with remains of fishing nets. In addition, plankton samples were taken monthly and water salinity and temperature were recorded. Between July 2006 and June 2007, the collectors were deployed monthly in the subtidal zone of two nearby localities and collected two months later. The recovered crabs were classified into four stages: settlers, recruits, advanced juveniles and mature crabs. There were differences in the presence of stages among collector types and seasons but not between localities. Settlers and recruits were abundant on the panels with synthetic lawn, while late juvenile and mature females were more frequent in the boxes. Larval stages occur between July and February, and only zoeas I and II were found. The males, which were only represented by early juveniles, were exclusively found on the panels with synthetic lawn, from where they would subsequently migrate to cryptic habitats such as the holdfast of Macrocystis pyrifera. Settlement occurs between September and April. Settlers showed a peak in abundance during November–December, while the recruits showed two peaks, one in December and the other in February–March. For late juveniles, the maximum abundance was recorded in April–May. Ovigerous females were found between May and September, when the experiment ended. Settlement and recruitment of H. planatus in Golfo San Jorge occur over a prolonged period. Individuals may undergo shifts in microhabitat use during this period, probably related to the search for food and shelter, and avoidance of predation and cannibalism.
Trematode fauna ofHydrobia ulvae(Gastropoda: Prosobranchia) in a eutrophic temperate estuary
Authors: Bordalo M.D. , Ferreira S.M. , Jensen K.T. , Pardal M.A.
Published: December 2010

Digenean trematodes infecting the mud snailHydrobia ulvaewere studied at two key sites of the Mondego Estuary (Portugal), from January 1993 to September 1995: a mud flat covered by the seagrassZostera noltii, and a bare sand flat where seasonal macroalgal blooms occurred as a result of eutrophication. Digeneans belonging to Microphallidae, Notocotylidae, Haploporidae and Heterophyidae were recorded in snails from both sites whereas representatives from Echinostomatidae were only found in snails from the seagrass bed. The density of infected snails was higher at the seagrass bed than at the eutrophic area partly reflecting the difference in population structure ofH. ulvaebetween sites. TheZostera noltiibed supports an abundant and well-structured mud snail population, with all size-classes represented, in contrast to a less abundant and juvenile dominated population in the eutrophic area. In theZ. noltiibed no clear seasonal and interannual patterns emerged in the infection densities. In the eutrophic area, the density of infected individuals increased in the presence of algae, and decreased during the occurrence of occasional flood events. Small scale spatial and temporal patterns in the prevalence of digenean trematodes in mud snails were therefore demonstrated within the Mondego Estuary that has experienced a mixture of anthropogenic impact and climate instability.
Increasing hospitalizations for serious skin infections in New Zealand children, 1990–2007
Authors: O'SULLIVAN C. E. , BAKER M. G. , ZHANG J.
Published: December 2010

The incidence of serious skin infections in New Zealand children is significantly higher than in comparative countries. This study aimed to describe the epidemiology of these infections and identify changes in disease distribution over time. Discharge data were analysed for all children admitted to a New Zealand public hospital with a serious skin infection during the period 1990–2007. Patient and admission variables were compared between 1990–1999 and 2000–2007. The incidence of serious skin infections almost doubled from 298·0/100 000 in 1990 to 547·3/100 000 in 2007. The highest rates were observed in boys, preschool-aged children, Māori and Pacific children, those living in deprived neighbourhoods, urban areas and northern regions. Over time there were disproportionate increases in infection rates in Māori and Pacific children and children from highly deprived areas. Serious skin infections are an increasing problem for New Zealand children. Worsening ethnic and socioeconomic health inequalities may be contributing to increasing rates.
MACHLUP ON THE TRANSFER PROBLEM
Authors: ORMAZABAL KEPA M
Published: December 2010

This paper intends to provide a comprehensive and critical survey of the valuable but neglected contributions of Fritz Machlup to the debate on the Transfer Problem. Machlup took three different and conflicting lines of approach to the problem in the course of his lifelong study of it. The third, which is of a basically monetary character, provides original results, especially in relation to the demand-oriented and quantitative approach that dominates in the standard literature.
Design improvements and tests of a laser positioning system for the Taiwan Photon Source girder system
Authors: Hsu Keng-Hao , Chen Mei-Ling , Ho H. C. , Wang H. S. , Tsai Y. L. , Lai W. Y. , Tseng T. C. , Perng S. Y. , Hsu K. H. , Chen J. R.
Published: December 2010

A precise laser positioning system had been preliminarily developed for the girder system of the Taiwan Photon Source. This laser positioning system, a part of a girder auto-alignment scheme, will be installed on the girders located at both sides of each straight section of the storage ring. The system is composed of a laser and four sets of a position sensing device (PSD). The laser, held on one girder, propagates 13 m along the girder and plays the role of a reference line of girders of the straight section. Based on the laser linear characteristics, the other girder can be adjusted and aligned by a cam mover according to PSD data. To achieve superior precision, the whole laser positioning system should be constructed stably. After making some improvements to eliminate the unstable terms, the precision of the laser positioning system can achieve 2 µm at 13 m propagating distance every 4 h.
Test of precision weak-link stage systems with large travel range and subnanometre-scale resolution
Authors: Shu D. , Maser J.
Published: December 2010

The precision ball-bearing- or roller-bearing-based stage systems provide large travel range. However, they have difficulties in meeting subnanometre resolution, high tilting stiffness and high straightness of trajectory with a single guiding system. It is always a dream to have a compact single flexure stage to cover a large travel range with very high positioning resolution. Based on an advanced structure design with the laminar overconstrained weak-link technique, we have designed and constructed a two-dimensional linear precision weak-link stage system for nanopositioning of a specimen holder for the linear multilayer Laue lenses test setup at the Advanced Photon Source Sector 26. This system provides subnanometre resolution, coupled with subnanometre metrology at a travel range of several millimetres. The two-dimensional weak-link stage system is designed with high structure stiffness using laminar overconstrained weak-link mechanisms. In this paper we present the preliminary test results of a linear precision weak-link stage system with subcentimetre travel range and subnanometre positioning resolution.
New optical mount design for Canadian Light Source far infrared beamline
Authors: May T. , Chen S. , Beauregard D. , Taylor D. , Johnson T.
Published: December 2010

The Canadian Light Source far infrared (IR) beamline uses seven mirrors to transport the IR light to the spectrometer experimental station (May et al. 2006). A new mirror mount provides more stability and precision control of mirror alignment. The design uses a gimbal arrangement that reflects the IR beam through 90°. Internal motor actuators for 2° of angular rotation (pitch and roll) and 1° of translation drive the mount. The two independent rotation axes intersect at the mirror centre to minimize translation offset when rotated. Translation along the incoming beam axis allows focus adjustment of the elliptical mirrors mounted. Beam steering using closed loop control with position feedback is precise and repeatable. Piezo-actuator tilting mirrors in an active optics system use this gimbal design for mounting. The design is compact and scales to the size of the mirror to be mounted; this allows installing new components into the existing chambers. We present features of the mount that include in-vacuum operation (Ultra High Vacuum (UHV) possible with change of motor type), economic materials and ability to handle heavy elements of 33 kg or more.
Thermal stability optimization of the ESRF nano hutch
Authors: Baker R. , Marion P. , Zhang L. , Marchial T. , Mackrill P. , Favier F.
Published: December 2010

The ESRF upgrade programme includes a number of extended beamlines in which instrumentation stability, be it mechanical or thermal, will be of utmost importance. Significant efforts are being made at every stage of design to increase stiffness and minimize thermal drift, but a thermally stable environment would greatly facilitate instrument conception and enhance overall performance. A numerical model of the most stable existing ESRF experimental hutch is detailed. With the aim to enhance thermal performance of future ‘nano hutches’, several optimization studies, both spatial and transient, have been performed on this model. Results from these studies and associated recommendations for future nano hutch design improvements are presented.
Fitness, sport et pression artérielle
Authors: Gojanovic
Published: December 2010

Nach einem aeroben Training, aber auch nach einem Krafttraining senkt sich der Blutdruck für einige Stunden ab, nach ersterem hält der Effekt länger an als nach letzterem. Regelmässiges Training kann den Blutdruck sowohl in Ruhe als auch bei Aktivität (24-h-Blutdruckmessung) senken. Dabei spielen verschiedene Mechanismen wie verminderter peripherer Widerstand, verbesserte Endothelfunktion, verminderte sympathische und Plasma-Renin-Aktivität, strukturelle Gefässveränderungen und Modulationen der Barorezeptoren eine Rolle. Vielversprechend scheinen neuere Übungen mit exzentrischen oder isometrischen Kontraktionen der Hände (Hand grip) zu sein. Wegen einer Erhöhung des Gefässwiderstandes galt Krafttraining lange als schädlich für die Gefässe. Ein moderates Krafttraining kombiniert mit einem aeroben Training hat aber insgesamt durchaus einen günstigen Effekt.
Earthquakes along the East African Rift System: A multiscale, system‐wide perspective
Authors: Yang Zhaohui , Chen Wang‐Ping
Published: December 2010

On the basis of a comprehensive data set of precisely determined depths of 121 large to moderate‐sized earthquakes along and near the entire East African Rift System (EARS), there are three distinct patterns in focal depths which seem to correlate with progressive stages in the development of the largest active rift in the world. First, away from both ends of the western, younger branch of the EARS, very large (Mw ≥ 7) earthquakes occurred in the top 15 km of the crust where surficial expressions of rifting are yet to appear. Curiously, there are unusually deep aftershocks reaching down to 35 ± 3 km. Second, under well‐developed but amagmatic rift segments, focal depths show a bimodal distribution, with peaks centered near depths of about 15 ± 5 km and 35 ± 5 km. This pattern is present both under the main axis of the EARS, where rift zone have lengths approaching 1000 km, and beneath rift units 10 times shorter in length. Underside reflections off the Moho indicate that at least part of the second peak in seismicity is due to mantle earthquakes down to 44 ± 4 km, attesting to high differential stress in the mantle lithosphere which is capable of accumulating seismogenic, elastic strain (the “jelly sandwich” rheology). Third, beneath magmatic segments of well‐developed rifts, seismicity is largely confined to the upper 15 km of the crust as observed previously, akin to the pattern along mid‐ocean ridges where plastic flow due to high temperature inhibits accumulation of shear stress deep in the lithosphere.
Steric and mass‐induced sea level variations in the Mediterranean Sea revisited
Authors: García‐García D. , Chao B. F. , Boy J.‐P.
Published: December 2010

The total sea level variation (SLV) is the combination of steric and mass‐induced SLV, whose exact shares are key to understanding the oceanic response to climate system changes. Total SLV can be observed by radar altimetry satellites such as TOPEX/POSEIDON and Jason 1/2. The steric SLV can be computed through temperature and salinity profiles from in situ measurements or from ocean general circulation models (OGCM), which can assimilate the said observations. The mass‐induced SLV can be estimated from its time‐variable gravity (TVG) signals. We revisit this problem in the Mediterranean Sea estimating the observed, steric, and mass‐induced SLV, for the latter we analyze the latest TVG data set from the GRACE (Gravity Recovery and Climate Experiment) satellite mission launched in 2002, which is 3.5 times longer than in previous studies, with the application of a two‐stage anisotropic filter to reduce the noise in high‐degree and ‐order spherical harmonic coefficients. We confirm that the intra‐annual total SLV are only produced by water mass changes, a fact explained in the literature as a result of the wind field around the Gibraltar Strait. The steric SLV estimated from the residual of “altimetry minus GRACE” agrees in phase with that estimated from OGCMs and in situ measurements, although showing a higher amplitude. The net water fluxes through both the straits of Gibraltar and Sicily have also been estimated accordingly.
Constraints on Europa's surface properties from primary and secondary crater morphology
Authors: Bierhaus E. B. , Schenk P. M.
Published: December 2010

We investigate the near‐surface properties of Europa's ice shell by examining small crater morphology; we use both primary and secondary craters for our analysis. For primary craters, the simple‐to‐complex transition provides an estimate of 0.19–0.36 MPa for the cratering effective strength. Through the aggregate statistics of over 100 profiles, we find that secondary craters on Europa tend toward smaller depth‐to‐diameter (d/D) ratios than primary craters, consistent with observations on other cratered surfaces (the Moon and Mars). In addition, we find that adjacent secondaries tend to be more shallow than distant secondaries, also consistent with trends seen on the Moon and Mars. The presence of numerous and far‐flung secondaries requires a solid, competent surface for spallation that is inconsistent with weak ice. Although the effective strength evaluated by crater scaling laws does not have a direct quantitative relationship to lab‐based measurements of shear or tensile strength, comparison to other observationally derived effective strengths and geologic materials suggests that the mechanical properties of Europa's surface ice should be consistent with terrestrial measurements of cold ice.
Two‐zone transient storage modeling using temperature and solute data with multiobjective calibration: 1. Temperature
Authors: Neilson B. T. , Chapra S. C. , Stevens D. K. , Bandaragoda C.
Published: December 2010

This paper presents the formulation and calibration of the temperature portion of a two‐zone temperature and solute (TZTS) model which separates transient storage into surface (STS) and subsurface transient storage (HTS) zones. The inclusion of temperature required the TZTS model formulation to differ somewhat from past transient storage models in order to accommodate terms associated with heat transfer. These include surface heat fluxes in the main channel (MC) and STS, heat and mass exchange between the STS and MC, heat and mass exchange between the HTS and MC, and heat exchange due to bed and deeper ground conduction. To estimate the additional parameters associated with a two‐zone model, a data collection effort was conducted to provide temperature time series within each zone. Both single‐objective and multiobjective calibration algorithms were then linked to the TZTS model to assist in parameter estimation. Single‐objective calibrations based on MC temperatures at two different locations along the study reach provided reasonable predictions in the MC and STS. The HTS temperatures, however, were typically poorly estimated. The two‐objective calibration using MC temperatures simultaneously at two locations illustrated that the TZTS model accurately predicts temperatures observed in MC, STS, and HTS zones, including those not used in the calibration. These results suggest that multiple data sets representing different characteristics of the system should be used when calibrating complex in‐stream models.
Two‐zone transient storage modeling using temperature and solute data with multiobjective calibration: 2. Temperature and solute
Authors: Neilson B. T. , Stevens D. K. , Chapra S. C. , Bandaragoda C.
Published: December 2010

This paper presents the multiobjective calibration results for temperature and solute from a two‐zone temperature and solute (TZTS) model which separates transient storage into surface (STS) and subsurface (HTS) transient storage components. This model contains terms associated with surface heat fluxes in the main channel (MC) and STS, heat and mass exchange between the STS and MC, heat and mass exchange between the HTS and MC, and heat exchange due to bed and deeper ground conduction. To estimate the additional parameters associated with a multiple‐zone model, a data collection effort was conducted to provide temperature time series and solute tracer curves representing the movement of heat and/or solute through each zone. A multiobjective calibration algorithm was linked to the TZTS model to assist in parameter estimation and to provide information about parameter uncertainty and tradeoffs associated with matching different combinations of observations (e.g., solute and/or temperature data gathered in various zones). Results generated from three different combinations of calibration data illustrated that the two‐zone model accurately reproduces temperatures and tracer concentrations observed in different zones when considered independently. However, there were many parameter sets that resulted in objectively indistinguishable results. When tracer and temperature observations were considered simultaneously in model calibration, the simplistic representation of the surface and subsurface zones did not adequately reproduce both observation types in each zone. If the uncertainty in model parameters and the data are taken into account, however, the results of the study suggest that it is plausible to use temperature and tracer information simultaneously to better inform transient storage modeling approaches.
Reconciling astrochronological and 40Ar/39Ar ages for the Matuyama‐Brunhes boundary and late Matuyama Chron
Authors: Channell J. E. T. , Hodell D. A. , Singer B. S. , Xuan C.
Published: December 2010

When five Matuyama‐Brunhes (M‐B) boundary records from the North Atlantic are placed on isotope age models, produced by correlation of the δ18O record directly or indirectly to an ice volume model, the M‐B boundary lies consistently at the young end of marine isotope stage 19 with a mean age for the midpoint of the reversal of 773.1 ka (standard deviation = 0.4 kyr), ∼7 kyr younger than the presently accepted astrochronological age for this polarity reversal (780–781 ka). Two recently proposed revisions of the age of the 40Ar/39Ar Fish Canyon sanidine (FCs) standard to 28.201 ± 0.046 Ma and 28.305 ± 0.036 Ma would adjust 40Ar/39Ar ages applicable to the M‐B boundary (and other reversals and excursions back to 1.2 Ma) to ages older than the new astrochronological ages by 8–24 kyr. The variables used to construct the ice volume models cannot account for the discrepancy. The FCs standard age that best fits the astrochronological ages is 27.93 Ma, which is within the uncertainty associated with the commonly used value of 28.02 (±0.16) Ma but younger than the recently proposed FCs ages. The EDC2 and EDC3 age models in the Dome C (Antarctic) ice core yield ages of 771.7 ka and 766.4 ka, respectively, for the 10Be flux peak that denotes the paleointensity minimum at the reversal boundary, implying that the EDC2 (rather than EDC3) age model is consistent with the observations from marine sediments, at least close to the M‐B boundary.
A hydrographic transient above the Salty Dawg hydrothermal field, Endeavour segment, Juan de Fuca Ridge
Authors: Kellogg J. P. , McDuff R. E.
Published: December 2010

During systematic repeat hydrography cruises to the Endeavour segment of the Juan de Fuca Ridge in the summers of 2004, 2005, and 2006, we encountered a transient increase in the water column heat content above the Salty Dawg hydrothermal field. First observed in July 2005 and mapped in greater detail in August 2005, this feature was not a typical event or megaplume since potential temperature anomalies were continuously elevated from the plume top to the seafloor. During the summer of 2005, the heat content in the waters above Salty Dawg was elevated ∼30 TJ, and the plume top was over 150 m higher in the water column than the other years measured. Based on scaling analyses, an order of magnitude increase in the volume flux from Salty Dawg would be required to generate a neutrally buoyant plume of this size. This observation was unexpected because no substantial earthquakes were detected in the time frame of this increased heat flux. The duration of the transient suggests possible forcing mechanisms: advancement of a cracking front, a small‐scale dike intrusion, aseismic crustal movement, fracture of a flow constriction to a previously unaccessible reservoir, an increase of heat in an underlying magma chamber, or movement of melt within the axial magma chamber. The transient disappeared before returning in August 2006, likely due to thermal expansion of shallow host rock, decreasing the permeability. Should such increases in seafloor heat flux prove to be common, the rate of hydrothermal cooling could be faster than previously thought.
Wave energy asymmetry in shallow bays
Authors: Fagherazzi S. , Mariotti G. , Porter J. H. , McGlathery K. J. , Wiberg P. L.
Published: December 2010

Storm surges along the coastline of the United States are often driven by along‐shore winds triggering cross‐shore Ekman transport. Here we show that this mechanism creates ideal conditions for large wave events in the shallow bays characterizing much of the Atlantic and Gulf of Mexico coastlines. A positive feedback enhances wave formation during along‐shore wind events, affecting the spatial distribution of waves and wave‐forced erosion in shallow bays at a continental scale.
Quantifying the negative feedback of vegetation to greenhouse warming: A modeling approach
Authors: Bounoua L. , Hall F. G. , Sellers P. J. , Kumar A. , Collatz G. J. , Tucker C. J. , Imhoff M. L.
Published: December 2010

Several climate models indicate that in a 2 × CO2 environment, temperature and precipitation would increase and runoff would increase faster than precipitation. These models, however, did not allow the vegetation to increase its leaf density as a response to the physiological effects of increased CO2 and consequent changes in climate. Other assessments included these interactions but did not account for the vegetation down‐regulation to reduce plant's photosynthetic activity and as such resulted in a weak vegetation negative response. When we combine these interactions in climate simulations with 2 × CO2, the associated increase in precipitation contributes primarily to increase evapotranspiration rather than surface runoff, consistent with observations, and results in an additional cooling effect not fully accounted for in previous simulations with elevated CO2. By accelerating the water cycle, this feedback slows but does not alleviate the projected warming, reducing the land surface warming by 0.6°C. Compared to previous studies, these results imply that long term negative feedback from CO2‐induced increases in vegetation density could reduce temperature following a stabilization of CO2 concentration.
A Monte Carlo paradigm for capillarity in porous media
Authors: Lu Ning , Zeidman Benjamin D. , Lusk Mark T. , Willson Clinton S. , Wu David T.
Published: December 2010

Wet porous media are ubiquitous in nature as soils, rocks, plants, and bones, and in engineering settings such as oil production, ground stability, filtration and composites. Their physical and chemical behavior is governed by the distribution of liquid and interfaces between phases. Characterization of the interfacial distribution is mostly based on macroscopic experiments, aided by empirical formulae. We present an alternative computational paradigm utilizing a Monte Carlo algorithm to simulate interfaces in complex realistic pore geometries. The method agrees with analytical solutions available only for idealized pore geometries, and is in quantitative agreement with Micro X‐ray Computed Tomography (microXCT), capillary pressure, and interfacial area measurements for natural soils. We demonstrate that this methodology predicts macroscopic properties such as the capillary pressure and air‐liquid interface area versus liquid saturation based only on the pore size information from microXCT images and interfacial interaction energies. The generality of this method should allow simulation of capillarity in many porous materials.
Identification of substorm onset location and preonset sequence using Reimei, THEMIS GBO, PFISR, and Geotail
Authors: Zou S. , Moldwin M. B. , Lyons L. R. , Nishimura Y. , Hirahara M. , Sakanoi T. , Asamura K. , Nicolls M. J. , Miyashita Y. , Mende S. B. , Heinselman C. J.
Published: December 2010

We present state‐of‐the‐art multiple instrument observations of an isolated substorm on October 12, 2007. The auroral breakup was observed simultaneously by Reimei, THEMIS ASI, and PFISR. The footprint of Geotail was also near the breakup. These observations allow for detailed study of the breakup location in terms of large‐ and small‐scale auroral morphology, particle precipitation, and ionospheric convection, which has not previously been achieved. It also allows for detailed identification of the sequence leading to the breakup. We report the first spaceborne high spatial and temporal resolution images of part of a breakup arc and a wave‐like auroral enhancement captured by Reimei. Observations suggest a sudden plasma sheet thinning initiated ∼10 min before the onset. Wave‐like auroral enhancements were observed twice at the most equatorward arc ∼3 min and ∼1 min before the breakup. These enhancements are likely due to some near‐Earth instability, such as ballooning instability. Unlike the usual substorm sequence, this most equatorward arc did not develop into the breakup arc but remained almost stable until being engulfed by the auroral equatorward expansion from higher latitude after onset. The wave‐like auroral enhancement was associated with three fine inverted V arcs and embedded within energetic ion precipitation. Following this enhancement, an arc, likely a poleward boundary intensification, formed at higher latitude just adjacent to the plasma sheet boundary layer (PSBL). This arc then extended southwestward and led to the breakup arc, which was located poleward of the wavy structures. Assuming longitudinal homogeneity of ion precipitation over 1°, this breakup arc was located in a region without ion precipitation just poleward of the energetic ion precipitation. These observations suggest the possible existence of a low‐entropy flow channel associated with the arc adjacent to the PSBL, which might be associated with instability in the near‐Earth plasma sheet responsible for the auroral breakup.
Understanding large SEP events with the PATH code: Modeling of the 13 December 2006 SEP event
Authors: Verkhoglyadova O. P. , Li G. , Zank G. P. , Hu Q. , Cohen C. M. S. , Mewaldt R. A. , Mason G. M. , Haggerty D. K. , von Rosenvinge T. T. , Looper M. D.
Published: December 2010

The Particle Acceleration and Transport in the Heliosphere (PATH) numerical code was developed to understand solar energetic particle (SEP) events in the near‐Earth environment. We discuss simulation results for the 13 December 2006 SEP event. The PATH code includes modeling a background solar wind through which a CME‐driven oblique shock propagates. The code incorporates a mixed population of both flare and shock‐accelerated solar wind suprathermal particles. The shock parameters derived from ACE measurements at 1 AU and observational flare characteristics are used as input into the numerical model. We assume that the diffusive shock acceleration mechanism is responsible for particle energization. We model the subsequent transport of particles originated at the flare site and particles escaping from the shock and propagating in the equatorial plane through the interplanetary medium. We derive spectra for protons, oxygen, and iron ions, together with their time‐intensity profiles at 1 AU. Our modeling results show reasonable agreement with in situ measurements by ACE, STEREO, GOES, and SAMPEX for this event. We numerically estimate the Fe/O abundance ratio and discuss the physics underlying a mixed SEP event. We point out that the flare population is as important as shock geometry changes during shock propagation for modeling time‐intensity profiles and spectra at 1 AU. The combined effects of seed population and shock geometry will be examined in the framework of an extended PATH code in future modeling efforts.
Multiscale‐multifluid simulations of the 26 February 2008 substorm: Evidence for internal triggering of a substorm
Authors: Harnett E. M. , Winglee R. M. , Lerud T.
Published: December 2010

Multiscale‐multifluid simulations are used to provide high‐resolution (∼470 km) simulations of the 26 February 2008 substorm that was well observed by the THEMIS spacecraft to investigate whether the substorm was internally or externally triggered. This substorm occurred during an extended (1 h 45 min) period of weak (−2.5 to −1.5 nT) southward interplanetary magnetic field (IMF). Simulation results show that this substorm was internally triggered well before the IMF start to become more northerly. The southward IMF leads to an enhancement in the cross‐polar cap potential, strong thinning of the current sheet, and pseudo‐breakup in association with patchy reconnection. The southward IMF also produces an enhancement in the outflow of ionospheric oxygen into the current sheet. Because of the tilt of the magnetic field the strongest outflows originate from the southern polar cap. The arrival of these heavy ions in the tail occurs about 10 min prior to the observed substorm onset and leads to enhanced tail reconnection, including flux rope development and fast earthward flows. The interaction of these fast flows at the inner edge of the plasma sheet is closely associated with auroral onset, indicating that the substorm is internally triggered. Comparison with THEMIS data suggests that reconnection occurred earlier than THEMIS observations. The results show onset is associated with processes at the inner edge of the plasma sheet and is not directly related to the onset of reconnection. Comparison with THEMIS data indicates that processes at scale lengths less than 500 km are occurring.
Associations between Fermi Gamma‐ray Burst Monitor terrestrial gamma ray flashes and sferics from the World Wide Lightning Location Network
Authors: Connaughton V. , Briggs M. S. , Holzworth R. H. , Hutchins M. L. , Fishman G. J. , Wilson‐Hodge C. A. , Chaplin V. L. , Bhat P. N. , Greiner J. , von Kienlin A. , Kippen R. M. , Meegan C. A. , Paciesas W. S. , Preece R. D. , Cramer E. , Dwyer J. R. , Smith D. M.
Published: December 2010

We report on a search for correlations between terrestrial gamma ray flashes (TGFs) detected by the Fermi Gamma‐ray Burst Monitor (GBM) and lightning strokes measured using the World Wide Lightning Location Network (WWLLN). We associate 15 of a total 50 GBM‐detected TGFs with individual discharges. We establish the relative timing between the TGF and the lightning stroke to an accuracy of <50 μs, and find that in 13 of these 15 lightning‐TGF associations, the lightning stroke and the peak of the TGF are simultaneous to ∼40 μs. This suggests that a large fraction of TGFs are coincident with lightning discharges. The two nonsimultaneous associations do not show a consistent TGF‐lightning stroke temporal sequence. All 15 associations are with sferics within 300 km of the subspacecraft position. For those TGFs not correlated with a particular lightning stroke, we find storm activity within 300 km of the subspacecraft position in all but four of the TGFs. For three of these four TGFs, we find storm activity very close to one of the magnetic footprints of the spacecraft position. We associate the subspacecraft TGFs with gamma ray events and the footprint events with electrons traveling along magnetic field lines before hitting the Fermi spacecraft.
Using a global magnetohydrodynamic model to study the start of the substorm recovery phase
Authors: Farr N. L. , Baker D. N. , Wiltberger M.
Published: December 2010

Magnetospheric substorms are a key manifestation of the transfer of energy from the solar wind to the Earth. Substorms consist of a loading of energy from the solar wind via magnetic reconnection and then a rapid release of that energy. One of the results of this energy release is the intense brightening of the aurora observed in the Earth's high‐latitude regions. At some point, the dissipation of energy peaks and the system recovers. This paper focuses on addressing the question of what causes the transition to the recovery phase of the substorm typically defined by the retreat of the substorm magnetic reconnection site, or neutral line, in the magnetotail. One suggested hypothesis is that the expansion of the dipolarization of the magnetic field in the inner magnetosphere causes the neutral line to move tailward. We use the Lyon‐Fedder‐Mobarry magnetohydrodynamic code to model seven substorms to examine what causes the neutral line retreat in the simulation. We conclude that while the simulation reproduces the substorms with the loading and unloading of energy, the retreat of the neutral line is a directly driven process that is controlled by the solar wind.
On the entry and transit of high‐density plasma across the polar cap
Authors: Oksavik K. , Barth V. L. , Moen J. , Lester M.
Published: December 2010

Observations are presented from SuperDARN and the EISCAT Svalbard Radar of two intense polar cap patch events on 6 February 2001. The interplanetary magnetic field (IMF) was dominated by a large positive By component, and for both events the electron density exceeded 1012 m−3 in the F region. With SuperDARN we tracked the events all the way across the polar cap, from the dayside Svalbard sector to the nightside Alaska sector. The flow speed was highly dynamic and pulsed, and both patches underwent substantial rotation in the polar cap. On the nightside the leading edge had become the trailing edge. It suggests that the first patch to enter the polar cap on the dayside may not always be the first patch to reach the nightside; plasma might be stagnant in the polar cap or even overtaken. The study also provides evidence that momentum transfer in the dayside polar cap can last significantly longer than 10 min after reconnection, especially for extremely long field lines where IMF By is dominating, i.e., on “old open field lines.” Knowledge of the solar wind driver and the coupling processes is therefore extremely important for predicting the motion of a polar cap patch event across the polar cap. Gradients in the plasma flow associated with the rotation of the extreme density may in itself lead to a stronger growth of ionospheric irregularities. These irregularities may continue to grow all the way across the polar cap. The result is more efficient creation of ionospheric irregularities.
Dayside field‐aligned current source regions
Authors: Wing Simon , Ohtani Shin‐ichi , Newell Patrick T. , Higuchi Tomoyuki , Ueno Genta , Weygand James M.
Published: December 2010

The source regions of region‐0 (R0), region‐1 (R1), and region‐2 (R2) field‐aligned currents (FACs) were statistically determined using DMSP particle precipitation and magnetometer data. Each FAC sheet originates from more than one region in the magnetosphere, depending on the latitude and the magnetic local time (MLT). R2 originates mostly from the central plasma sheet (CPS) and boundary plasma sheet (BPS) in the morning and from the CPS, BPS, and inner magnetosphere in the afternoon, all of which are on closed field lines. Near noon, some R2 may originate from the low‐latitude boundary layer (LLBL), which is located near the magnetopause and can be open or closed. R1 mostly maps to the BPS, hence on closed field lines, in morning and afternoon, but near noon, it maps mostly to the LLBL. The LLBL source region can be found more frequently in the dawn–noon sector than in the noon–dusk sector. On the other hand, R0 is located mostly on open field lines and is associated mostly with mantle precipitation. However, the mantle precipitation has a dependency on the polarity of R0. Within up‐flowing R0, sometimes an upward field‐aligned electric field, which accelerates electron downward and retards ion precipitation, modifies mantle distribution to look more like those of polar rain or BPS. This electric field has the opposite polarity to the background electric field that maintains charge‐quasi‐neutrality and that limits some solar wind electrons from entering the magnetosphere in the mantle and polar rain regions. Implications to current generation mechanisms are discussed.
Automatic Whistler Detector and Analyzer system: Implementation of the analyzer algorithm
Authors: Lichtenberger János , Ferencz Csaba , Hamar Daniel , Steinbach Peter , Rodger Craig J. , Clilverd Mark A. , Collier Andrew B.
Published: December 2010

The full potential of whistlers for monitoring plasmaspheric electron density variations has not yet been realized. The primary reason is the vast human effort required for the analysis of whistler traces. Recently, the first part of a complete whistler analysis procedure was successfully automated, i.e., the automatic detection of whistler traces from the raw broadband VLF signal was achieved. This study describes a new algorithm developed to determine plasmaspheric electron density measurements from whistler traces, based on a Virtual (Whistler) Trace Transformation, using a 2‐D fast Fourier transform transformation. This algorithm can be automated and can thus form the final step to complete an Automatic Whistler Detector and Analyzer (AWDA) system. In this second AWDA paper, the practical implementation of the Automatic Whistler Analyzer (AWA) algorithm is discussed and a feasible solution is presented. The practical implementation of the algorithm is able to track the variations of plasmasphere in quasi real time on a PC cluster with 100 CPU cores. The electron densities obtained by the AWA method can be used in investigations such as plasmasphere dynamics, ionosphere‐plasmasphere coupling, or in space weather models.