bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nutrient limitation of phytoplankton growth in Arctic lakes of the lower Mackenzie River Basin, northern Canada
Authors: Ogbebo Fortune E. , Evans Marlene S. , Waiser Marley J. , Tumber Vijay P. , Keating Jonathan J. 
Published: February 2009

Water chemistry and the nutrients limiting phytoplankton growth were examined in lakes located in the Northwest Territories, Canada, along a transect from the Mackenzie River Delta south to Travaillant Lake. This 230 km stretch spans gradients in vegetation types (tundra to boreal forest) and elevation (flooded by the Mackenzie River versus higher elevation lakes). Total phosphorus concentrations generally were typical of oligotrophic lakes (<10 µg·L–1), while nitrate and orthophosphate concentrations were below detection limits. Although some growth was noted in bioassays receiving single additions of nitrogen (N) or phosphorus (P), the greatest growth occurred in those bioassays in which nitrogen and phosphorus were added. This suggests that phytoplankton in the majority of study lakes were strongly co-limited by N and P irrespective of watershed type and Mackenzie River influence. Furthermore, it suggests that algal communities will be highly responsive to anthropogenic disturbances, which result in increased N and P loading to these lakes. Experimental results from March bioassays suggest that anthropogenic eutrophication would be exacerbated by increased temperatures (e.g., those associated with global warming).
Comparisons of Satellite-Derived Atmospheric Motion Vectors, Rawinsondes, and NOAA Wind Profiler Observations
Authors: Bedka Kristopher M. , Velden Christopher S. , Petersen Ralph A. , Feltz Wayne F. , Mecikalski John R. 
Published: February 2009

Abstract
Geostationary satellite-derived atmospheric motion vectors (AMVs) have been used over several decades in a wide variety of meteorological applications. The ever-increasing horizontal and vertical resolution of numerical weather prediction models puts a greater demand on satellite-derived wind products to monitor flow accurately at smaller scales and higher temporal resolution. The focus of this paper is to evaluate the accuracy and potential applications of a newly developed experimental mesoscale AMV product derived from Geostationary Operational Environmental Satellite (GOES) imagery. The mesoscale AMV product is derived through a variant on processing methods used within the University of Wisconsin—Madison Cooperative Institute for Meteorological Satellite Studies (UW-CIMSS) AMV algorithm and features a significant increase in vector density throughout the troposphere and lower stratosphere over current NOAA/National Environmental Satellite, Data, and Information Service (NESDIS) processing methods for GOES-12 Imager data. The primary objectives of this paper are to 1) highlight applications of experimental GOES mesoscale AMVs toward weather diagnosis and forecasting, 2) compare the coverage and accuracy of mesoscale AMVs with the NOAA/NESDIS operational AMV product, and 3) demonstrate the utility of 6-min NOAA Wind Profiler Network observations for satellite-derived AMV validation. Although the more conservative NOAA/NESDIS AMV product exhibits closer statistical agreement to rawinsonde and wind profiler observations than do the experimental mesoscale AMVs, a comparison of these two products for selected events shows that the mesoscale product better depicts the circulation center of a midlatitude cyclone, boundary layer confluence patterns, and a narrow low-level jet that is well correlated with subsequent severe thunderstorm development. Thus, while the individual experimental mesoscale AMVs may sacrifice some absolute accuracy, they show promise in providing greater temporal and spatial flow detail that can benefit diagnosis of upper-air flow patterns in near–real time. The results also show good agreement between 6-min wind profiler and rawinsonde observations within the 700–200-hPa layer, with larger differences in the stratosphere, near the mean top of the planetary boundary layer, and just above the earth’s surface. Despite these larger differences within select layers, the stability of the difference profile with height builds confidence in the use of 6-min, ∼404-MHz NOAA Wind Profiler Network observations to evaluate and better understand satellite AMV error characteristics.
A Comprehensive Habit Diagram for Atmospheric Ice Crystals: Confirmation from the Laboratory, AIRS II, and Other Field Studies
Authors: Bailey Matthew P. , Hallett John 
Published: February 2009

Abstract
Recent laboratory experiments and in situ observations have produced results in broad agreement with respect to ice crystal habits in the atmosphere. These studies reveal that the ice crystal habit at −20°C is platelike, extending to −40°C, and not columnar as indicated in many habit diagrams found in atmospheric science journals and texts. These diagrams were typically derived decades ago from laboratory studies, some with inherent habit bias, or from combinations of laboratory and in situ observations at the ground, observations that often did not account for habit modification by precipitation from overlying clouds of varying temperatures. Habit predictions from these diagrams often disagreed with in situ observations at temperatures below −20°C. More recent laboratory and in situ studies have achieved a consensus on atmospheric ice crystal habits that differs from the traditional habit diagrams. These newer results can now be combined to give a comprehensive description of ice crystal habits for the atmosphere as a function of temperature and ice supersaturation for temperatures from 0° to −70°C, a description dominated by irregular and imperfect crystals. Cloud particle imager (CPI) habit observations made during the Second Alliance Icing Research Study (AIRS II) and elsewhere corroborate this comprehensive habit description, and a new habit diagram is derived from these results.
Turbulence Structure of the Hurricane Boundary Layer between the Outer Rainbands
Authors: Zhang Jun A. , Drennan William M. , Black Peter G. , French Jeffrey R. 
Published: February 2009

Abstract
As part of the Coupled Boundary Layers Air–Sea Transfer (CBLAST)-Hurricane program, flights were conducted to directly measure turbulent fluxes and turbulence properties in the high-wind boundary layer of hurricanes between the outer rainbands. For the first time, vertical profiles of normalized momentum fluxes, sensible heat and humidity fluxes, and variances of three-dimensional wind velocities and specific humidity are presented for the hurricane boundary layer with surface wind speeds ranging from 20 to 30 m s−1. The turbulent kinetic energy budget is estimated, indicating that the shear production and dissipation are the major source and sink terms, respectively. The imbalance in the turbulent kinetic energy budget indicates that the unmeasured terms, such as horizontal advection, may be important in hurricane boundary layer structure and dynamics. Finally, the thermodynamic boundary layer height, estimated based on the virtual potential temperature profiles, is roughly half of the boundary layer height estimated from the momentum flux profiles. The latter height where momentum and humidity fluxes tend to vanish is close to that of the inflow layer and also of the maximum in the tangential velocity profiles.
Fidelity of Analytic Drop Size Distributions in Drizzling Stratiform Clouds Based on Large-Eddy Simulations
Authors: Kogan Yefim L. , Kogan Zena N. , Mechem David B. 
Published: February 2009

Abstract
Cloud microphysical parameterizations and retrievals rely heavily on knowledge of the shape of drop size distributions (DSDs). Many investigations assume that DSDs in the entire or partial drop size range may be approximated by known analytical functions. The most frequently employed approximations of function are of the type of gamma, lognormal, Khrgian–Mazin, and Marshall–Palmer. At present, little is known about the accuracy of these approximations. The authors employ a DSD dataset generated by the Cooperative Institute for Mesoscale Meteorological Studies Large-Eddy Simulation (CIMMS LES) explicit microphysics model for stratocumulus cases observed during the Atlantic Stratocumulus Transition Experiment (ASTEX) field project. The fidelity of analytic lognormal- and gamma-type DSD functions is evaluated according to how well they represent the higher-order moments of the drop spectra, such as precipitation flux and radar reflectivity. It is concluded that for boundary layer marine drizzling stratocumuli, a DSD based on the two-mode gamma distribution provides a more accurate estimate of precipitation flux and radar reflectivity than the DSD based on the lognormal distribution. The gamma distribution also provides a more accurate radar reflectivity field in two- and three-moment bulk microphysical models compared to the conventional Z–R relationship.
Saturation of the Internal Tides and Induced Mixing in the Abyssal Ocean
Authors: Muller Caroline J. , Bühler Oliver 
Published: February 2009

Abstract
As part of an ongoing effort to develop a parameterization of wave-induced abyssal mixing, the authors derive an heuristic model for nonlinear wave breaking and energy dissipation associated with internal tides. Then the saturation and dissipation of internal tides for idealized and observed topography samples are investigated. One of the main results is that the wave-induced mixing could be more intense and more confined to the bottom than previously assumed in numerical models. Furthermore, in this model wave breaking and mixing clearly depend on the small scales of the topography below 10 km or so, which is below the current resolution of global bathymetry. This motivates the use of a statistical approach to represent the unresolved topography when addressing the role of internal tides in mixing the deep ocean.
Heavy Precipitation Associated with Southern Appalachian Cold-Air Damming and Carolina Coastal Frontogenesis in Advance of Weak Landfalling Tropical Storm Marco (1990)
Authors: Srock Alan F. , Bosart Lance F. 
Published: February 2009

Abstract
An analysis is presented of Tropical Storm Marco (1990), a storm that dropped copious amounts of rain over the southeast United States. Marco was noteworthy because of its role in the formation and evolution of two distinct episodes of cold-air damming and coastal frontogenesis over Georgia and the Carolinas. These mesoscale features led to greater than 300 mm of precipitation in 2 days over the near-coastal southeast United States; much of the rain occurred while Marco was over 400 km away. This case is further complicated by two other nearby tropical cyclones, which affected Marco’s track and the overall rainfall distribution. Synoptic and mesoscale analyses of the development of the coastal front and cold-air damming episodes show that the location of Marco helped to orient low-level winds toward the Appalachians. As rain developed inland, a pocket of relatively cool air, the “cool pool,” formed near the mountain slopes and was partially blocked by the higher terrain. Low-level analyses show that the coastal front on the oceanward edge of the cool pool became a focusing mechanism for ascent and precipitation, as moist, tropical air advected inland by Marco was forced upward at the density gradient. The results indicate that a weak tropical cyclone can directly effectuate intense precipitation distant from the storm center, both by causing moist tropical flow toward land and by inducing mesoscale features that focus the precipitation and lead to heavy rainfall and flooding.
Weather Forecasts by the WRF-ARW Model with the GSI Data Assimilation System in the Complex Terrain Areas of Southwest Asia
Authors: Xu J. , Rugg S. , Byerle L. , Liu Z. 
Published: February 2009

Abstract
This paper will first describe the forecasting errors encountered from running the National Center for Atmospheric Research (NCAR) mesoscale model (the Advanced Research Weather Research and Forecasting model; ARW) in the complex terrain of southwest Asia from 1 to 31 May 2006. The subsequent statistical evaluation is designed to assess the model’s surface and upper-air forecast accuracy. Results show that the model biases caused by inadequate parameterization of physical processes are relatively small, except for the 2-m temperature, as compared to the nonsystematic errors resulting in part from the uncertainty in the initial conditions. The total model forecast errors at the surface show a substantial spatial heterogeneity; the errors are relatively larger in higher mountain areas. The performance of 2-m temperature forecasts is different from the other surface variables’ forecasts; the model forecast errors in 2-m temperature forecasts are closely related to the terrain configuration. The diurnal cycle variation of these near-surface temperature forecasts from the model is much smaller than what is observed.
Second, in order to understand the role of the initial conditions in relation to the accuracy of the model forecasts, this study assimilated a form of satellite radiance data into this model through the Joint Center for Satellite Data Assimilation (JCSDA) analysis system called the Gridpoint Statistical Interpolation (GSI). The results indicate that on average over a 30-day experiment for the 24- and 48-h (second 24 h) forecasts, the satellite data provide beneficial information for improving the initial conditions and the model errors are reduced to some degree over some of the study locations. The diurnal cycle for some forecasting variables can be improved after satellite data assimilation; however, the improvement is very limited.
Patient views on three key service areas within hospital COPD care
Authors: Roberts C Michael , Seiger Anil , Ingham Jane 
Published: February 2009

Objective The views of patients with Chronic Obstructive Pulmonary Disease (COPD) about three key services (non-invasive ventilation [NIV], early discharge schemes and rehabilitation) were sought in order to inform recommendations for the delivery of optimum care within a national programme of hospital COPD service development. Design Four focus groups were run involving 36 COPD patients, facilitated by two researchers. Tape recordings were transcribed and emergent grouped themes identified. Setting Four locations across the UK. Results Of the three service areas considered, two (NIV and early discharge) were unknown to the majority of patients despite their strong evidence base and national recommendations for implementation. Where patients were familiar with a service they made consistent and useful recommendations for improving care. Those recently hospitalized reported insufficient information provision for them to make personal informed choices about key management interventions. Conclusion Patients have important views on services with which they are familiar and if consulted can significantly contribute to their development. This report has identified a lack of knowledge amongst the majority of patients consulted about recent key NHS medical and service developments. At a group level this impairs the contributions that patients may make to forming service profiles. At an individual level, lack of prior knowledge places patients in a vulnerable position when admitted to hospital and asked to make informed decisions about their care.
A Spanish language narrative simulation to prevent horseback riding head injury among rural youth
Authors: Arrowsmith Heather E , Cole Henry P , Mazur Joan M 
Published: February 2009

Objective A Spanish language version of an exercise about adolescent horseback riders' exposure to traumatic brain injuries was integrated into the Spanish curriculum in a rural Kentucky high school. Design An exploratory case study design with two groups of students. Setting and Method Thirty-eight students, enrolled in intermediate Spanish IV and advanced Spanish V language classes, completed the exercise as part of their class work. Results The students' mean age was 16.3 years with a gender distribution of 32 females, 13 of whom were horseback riders, and six male non-riders. Only six of the 13 female riders reported wearing a helmet at least half the time, and four never wore a helmet. The Spanish V students (11 of whom were riders) scored significantly higher ( p <0.05) on four of the five exercise items than the Spanish IV students (two of whom were riders). However, the groups did not differ and scored low (55.3 per cent) on an item that involved recognizing pre-event contributors to the injury event. Students with riding experience scored significantly higher than non-riders ( p <0.05) in recognizing that donning a helmet prior to riding is the most effective way to prevent a head injury. Although students believed that wearing a helmet could prevent brain injuries, they did not think they were at risk. Conclusion The exercise was successfully integrated into both classes. Discussing its vocabulary and sentence structure prior to its administration would improve its effectiveness.
Cochrane review: information provision for stroke patients and their caregivers
Authors: Smith Jane , Forster Anne , Young John ,   On behalf of the Cochrane Group for information provision after stroke
Published: February 2009

Objective: To assess the effectiveness of information provision strategies in improving the outcome for stroke patients and/or their identified caregivers. Data sources: We searched: the Cochrane Stroke Group Trials Register; the Cochrane Central Register of Controlled Trials; electronic databases MEDLINE; EMBASE; CINAHL; PsycINFO; Science Citation Index and Social Science Citation Index; Assia; Index to UK theses; Dissertation Abstracts; ongoing trials and research registers; bibliographies of retrieved papers, relevant articles, and books; the Journal of Advanced Nursing. We also contacted researchers for additional information. Review methods: Two review authors independently assessed trial eligibility, extracted data and assessed methodological quality. Primary outcomes were knowledge about stroke and impact on mood. Meta-analyses were undertaken for the domains of knowledge, mood, satisfaction, and mortality. Results: Seventeen trials were identified and 11 contributed data to the meta-analyses. There were significant effects in favour of the intervention on patient knowledge (standardized mean difference (SMD) 0.29, 95% confidence interval (CI) 0.12 to 0.46), caregiver knowledge (SMD 0.74 95% CI 0.06 to 1.43), patient depression scores (weighted mean difference (WMD) -0.52, 95% CI -0.93 to -0.10), and one aspect of patient satisfaction (odds ratio (OR) 2.07, 95% CI 1.33 to 3.23). Post-hoc subgroup analyses showed that strategies which actively involved patient and caregivers had a significantly greater effect on patient anxiety (P<0.05) and depression (P<0.02) than passive strategies. Conclusion: There is some evidence to support the routine provision of information to stroke patients and their families. Although the best way to provide information is still not clear, the results of this review suggest that strategies which actively involve patients and caregivers should be used in routine practice.
Predicting accidental falls in people with multiple sclerosis — a longitudinal study
Authors: Nilsagård Y. , Lundholm Cecilia , Denison E. , Gunnarsson L-G. 
Published: February 2009

Objective: To investigate accidental falls and near fall incidents in people with multiple sclerosis with respect to clinical variables and the predictive values of four tests. Design: A longitudinal, multi-centred cohort study with prospectively collected falls. Procedures: Self-reported incidents during the three months following a standardized test procedure. Subjects: Seventy-six people with multiple sclerosis and an Expanded Disability Status Scale score between 3.5 and 6.0. Main outcome measures: Berg Balance Scale, Timed Up and Go cognitive, Four Square Step Test (FSST) and 12-item Multiple Sclerosis Walking Scale. Results: Forty-eight people (63%) registered 270 falls. Most falls occurred indoors during activities of daily life. We found a correlation of rs=0.57 between near falls and falls, and of rs = 0.82 between registered and retrospectively recalled falls. Fallers and non-fallers differed significantly regarding Expanded Disability Status Score (odds ratio (OR) 1.99, 95% confidence interval (CI) 1.22; 3.40), spasticity (OR 1.14, CI 1.02; 1.31), proprioception (OR 2.50, CI 1.36; 5.12) and use of walking aids (OR 2.27, CI 1.23; 4.37). Reported use of walking aids both indoors and outdoors increased the odds of falling fivefold while disturbed proprioception increased the odds 2.5—15.6 times depending on severity. The odds of falling were doubled for each degree of increased Expanded Disability Status Score and more than doubled for each degree of increased spasticity. The Berg Balance Scale, use of walking aids and Timed Up and Go cognitive best identified fallers (73—94%) and proprioception, Expanded Disability Status Score, 12-item Multiple Sclerosis Walking Scale and Four Square Step Test best identified non-fallers (75—93%). Conclusions: In clinical practice, looking at the use of walking aids, investigating proprioception and spasticity, rating Expanded Disability Status Score and using Berg Balance Scale or Timed Up and Go cognitive all contribute when identifying fallers.
Effects of aerobic or aerobic and resistance training on cardiorespiratory and skeletal muscle function in heart failure: a randomized controlled pilot trial
Authors: Mandic Sandra , Tymchak Wayne , Kim Daniel , Daub Bill , Quinney H Arthur , Taylor Dylan , Al-Kurtass Suhaib , Haykowsky Mark J 
Published: February 2009

Objective: To examined the effects of different training modalities on exercise capacity (Vo 2peak), systolic function, muscular strength and endurance and quality of life in heart failure patients. Design: Randomized controlled trial. Setting: Cardiac rehabilitation centre in Canada. Subjects: Forty-two individuals with heart failure (62 ± 12 years; New York Heart Association (NYHA) classes I—III). Interventions: Aerobic training (n = 14), combined aerobic and resistance training (n = 15) or usual care (n = 13) three times per week for 12 weeks. Main measures: (1) Vo 2peak measured by symptom-limited graded exercise test on cycle ergometer; (2) systolic function assessed by two-dimensional echocardiography; (3) muscular strength and muscular endurance measured by one-repetition maximum procedure; and (4) quality of life assessed by questionnaires. Results: In the intention-to-treat analysis, neither aerobic nor combined aerobic and resistance training significantly improved Vo2peak, systolic function or quality of life compared with usual care. However, combined aerobic and resistance training significantly improved upper extremity strength (40.7 (14.0)—48.5 (16.0) kg, P<0.05) and muscular endurance (5.7 (2.7)—11.6 (7.6) reps, P<0.05) compared with aerobic training or usual care. In compliant participants (exercise adherence 80%), Vo2peak increased in the aerobic group (16.9 (6.0)—19.0 (6.8), P= 0.026) and tended to increase in the combined training group (15.9 (5.0)—17.6 (5.6), P= 0.058) compared with usual care. Quality of life was improved in the aerobic group only. Conclusions: Both aerobic and combined aerobic and resistance training are effective interventions to improve Vo2peak in compliant heart failure patients. Combined training may be more effective in improving muscle strength and endurance.