bluuebunny/crossref_metadata_2025_split huggingface dataset:
TH‐C‐352‐03: Introduction and Clinical Use of Electronic Brachytherapy
Authors: Hiatt J 
Published: July 2008

Electronic Brachytherapy (EBT) is internal radiation therapy that involves placing a miniature x‐ray source inside the patient close to or in the tumor. Recently, one EBT system (Axxent, Xoft Inc., Fremont, CA) has been released for clinical use. Because of its novelty, EBT has been relatively unstudied thus far in the clinical setting and is consequently unfamiliar to many medical physicists. The EBT modality offers several advantages over the Ir‐192 standard of care HDR brachytherapy source. Because of the relatively low energy of the EBT device (50 kV), treatments can be delivered in an unshielded room in contrast to the shielding required for HDR brachytherapy. The low external exposure rate also allows staff to remain near the treatment couch during dose delivery, offering the opportunity to provide comfort and encouragement in close proximity to the patient.As yet, recommendations for the commissioning of an EBT system have not been officially drafted. However, commissioning an EBT system should include tests of well‐chamber constancy, beam stability, source positional accuracy, output stability, timer linearity, dummy marker/source position coincidence, controller functionality and safety interlocks and treatment planning data verification following AAPM TG43 recommendations.Early EBT systems focused on treatment of the breast, using an intracavitary balloon catheter surgically implanted in a lumpectomy excision cavity. In comparison to Ir‐192, the EBT treatment results in a higher dose on the applicator surface, an equivalent distribution over the target region and a lower dose to normal structures around the implant area. Recent FDA clearances will allow the extension of EBT to additional sites, including endometrial applications.This lecture will provide an overview of EBT, a commissioning procedure, and examples of its clinical use.Educational Objectives:1. Gain basic knowledge of EBT as a potential HDR‐alternative treatment modality.2. Understand a proposed commissioning protocol for an EBT system.3. Learn about the current clinical uses for EBT.Conflict of Interest: Partial financial support was provided by Xoft, Inc.
Platelet function testing: practice among UK National External Quality Assessment Scheme for Blood Coagulation participants, 2006
Authors: Jennings I , Woods T A L , Kitchen S , Walker I D 
Published: July 2008

Aims:Platelet function testing forms an important part of the laboratory investigation of a bleeding tendency; however, little standardisation and quality control is available for these tests. A UK National External Quality Assessment Scheme (UK NEQAS) for Blood Coagulation exercise sought to identify current practice among laboratories performing platelet function tests.Methods:A questionnaire was circulated in March 2006 to establish the current status of platelet function testing practice among participants of UK NEQAS. Participants were asked specifically about practice in bleeding time testing, PFA-100 analyser use, platelet aggregometry methodology and additional tests of platelet function.Results:169 returned questionnaires revealed that 26 centres used bleeding time, the PFA-100 analyser and platelet aggregometry in their investigations; 13 used bleeding time and the PFA-100 only; 33 used bleeding time and platelet aggregometry; and 23 used the PFA-100 with platelet aggregometry. 58 centres reported that they performed only bleeding times in their investigations, 10 reported use of the PFA-100 only, and 6 reported use of aggregometry only. Marked variability was observed in methodology for each of these tests, and in many cases no form of quality control was employed.Conclusions:The data confirmed the lack of standardisation in methodology employed in different centres. Updated guidelines and standardisation of platelet function assessment are required to facilitate comparability between centres.
Seasonal changes in aerobic fitness indices in elite cyclists
Authors: Sassi Aldo , Impellizzeri Franco M. , Morelli Andrea , Menaspà Paolo , Rampinini Ermanno 
Published: July 2008

The primary purpose of this study was to compare seasonal changes in cycling gross efficiency (GE) and economy (EC) with changes in other aerobic fitness indices. The secondary aim was to assess the relationship between maximum oxygen consumption, GE, and EC among elite cyclists. The relationships of maximum oxygen consumption with GE and EC were studied in 13 cyclists (8 professional road cyclists and 5 mountain bikers). Seasonal changes in GE and EC, predicted time to exhaustion (pTE), maximum oxygen consumption, and respiratory compensation point (RCP) were examined in a subgroup of 8 subjects, before (TREST) and after (TPRECOMP) the pre-competitive winter training, and during the competitive period (TCOMP). GE and EC were assessed during a constant power test at 75% of peak power output (PPO). Significant main effect for time was found for maximum oxygen consumption (4.623 ± 0.675, 4.879 ± 0.727, and 5.010 ± 0.663 L·min–1; p = 0.028), PPO (417.8 ± 46.5, 443.0 ± 48.0, and 455 ± 48 W; p < 0.001), oxygen uptake at RCP (3.866 ± 0.793, 4.041 ± 0.685, and 4.143 ± 0.643 L·min–1; p = 0.049), power output at RCP (330 ± 64, 354 ± 52, and 361 ± 50 W; p < 0.001), and pTE (17 ± 4, 30 ± 8, and 46 ± 17 min; p < 0.001). No significant main effect for time was found in GE (p = 0.097) or EC (p = 0.225), despite within-subject seasonal changes. No significant correlations were found between absolute maximum oxygen consumption and GE (r = –0.276; p = 0.359) or EC (r = –0.328; p = 0.272). However, cyclists with high maximum oxygen consumption values (i.e., over 80 mL·kg–1·min–1), showed low efficiency rates. Despite within-subject seasonal waves in cycling efficiency, changes in GE and EC should not be expected as direct consequence of changes in other maximal and submaximal parameters of aerobic fitness (i.e., maximum oxygen consumption and RCP).
Acute milk-based protein–CHO supplementation attenuates exercise-induced muscle damage
Authors: Cockburn Emma , Hayes Philip R. , French Duncan N. , Stevenson Emma , St Clair Gibson Alan 
Published: July 2008

Exercise-induced muscle damage (EIMD) leads to the degradation of protein structures within the muscle. This may subsequently lead to decrements in muscle performance and increases in intramuscular enzymes and delayed-onset muscle soreness (DOMS). Milk, which provides protein and carbohydrate (CHO), may lead to the attenuation of protein degradation and (or) an increase in protein synthesis that would limit the consequential effects of EIMD. This study examined the effects of acute milk and milk-based protein–CHO (CHO-P) supplementation on attenuating EIMD. Four independent groups of 6 healthy males consumed water (CON), CHO sports drink, milk-based CHO-P or milk (M), post EIMD. DOMS, isokinetic muscle performance, creatine kinase (CK), and myoglobin (Mb) were assessed immediately before and 24 and 48 h after EIMD. DOMS was not significantly different (p > 0.05) between groups at any time point. Peak torque (dominant) was significantly higher (p < 0.05) 48 h after CHO-P compared with CHO and CON, and M compared with CHO. Total work of the set (dominant) was significantly higher (p < 0.05) 48 h after CHO-P and M compared with CHO and CON. CK was significantly lower (p < 0.05) 48 h after CHO-P and M compared with CHO. Mb was significantly lower (p < 0.05) 48 h after CHO-P compared with CHO. At 48 h post-EIMD, milk and milk-based protein–CHO supplementation resulted in the attenuation of decreases in isokinetic muscle performance and increases in CK and Mb.
Sex differences in insulin action and body fat distribution in overweight and obese middle-aged and older men and women
Authors: Ferrara Cynthia M. , Goldberg Andrew P. , Nicklas Barbara J. , Sorkin John D. , Ryan Alice S. 
Published: July 2008

Controversy exists as to whether there are differences in insulin action between older men and women, and what factors contribute to these differences. This study tests the hypothesis that sex differences in regional fat distribution contribute to a disparity in insulin sensitivity in older men vs. older women. Healthy, older (50–71 years), sedentary men (n = 28) and women (n = 29) were recruited to participate in the study. Body fat, fat-free mass (FFM), and visceral (VAT) and subcutaneous abdominal (SAT) adipose tissue areas were measured by DXA and computed tomography (CT). For measurements of insulin-stimulated glucose disposal (M), insulin was infused at a constant rate of 240 pmol·m–2·min–1, and M was calculated between the 90th and 120th min of the hyperinsulinemic–euglycemic clamp. The men weighed 16% more and had 16% higher waist and 4% lower hip circumferences than women (p < 0.05 for all). Total fat mass and SAT were 21% and 33% lower and FFM was 49% higher in men than in women, whereas waist-to-hip ratio (WHR) and VAT:SAT ratio were 21% and 56% higher in men than in women (p < 0.05 for all). Although insulin concentrations during the glucose clamp were higher in men, M was 47% lower in men vs. women (21.7 ± 1.1 vs. 46.7 ± 3.1 µmol·L–1·kgFFM–1·min–1, p < 0.05). The sex-related differences in M persisted after controlling for insulin concentrations during the glucose clamp, for waist, WHR, and VAT:SAT. Older men are more insulin resistant than women, despite lower body fat and subcutaneous abdominal fat. This difference in insulin sensitivity is not explained by abdominal fat distribution, therefore other metabolic factors contribute to the sex differences in insulin sensitivity.
Dynamics of wood in stream networks of the western Cascades Range, Oregon
Authors: Czarnomski Nicole M. , Dreher David M. , Snyder Kai U. , Jones Julia A. , Swanson Frederick J. 
Published: July 2008

We develop and test a conceptual model of wood dynamics in stream networks that considers legacies of forest management practices, floods, and debris flows. We combine an observational study of wood in 25 km of 2nd- through 5th-order streams in a steep, forested watershed of the western Cascade Range of Oregon with whole-network studies of forest cutting, roads, and geomorphic processes over the preceding 50 years. Statistical and simple mass balance analyses show that natural process and forest management effects on wood input, transport processes, and decomposition account for observed patterns of wood in the stream network. Forest practices reduced wood amounts throughout the network; in headwater streams these effects are fixed in stream segments bordered by cuts and roads, but in larger channels they are diffused along the channel by fluvial transport of wood. Landforms and roads limited delivery of wood by debris flows to mainstem channels. Network dynamics studies and watershed management plans should include spatial patterns of debris flow initiation and runout, flood redistribution, and reduction of wood in the network by forest cutting and intentional wood removal from channels on time scales of forest succession and recurrence of major floods.
The value of timber inventory information for management planning
Authors: Borders B. E. , Harrison W. M. , Clutter M. L. , Shiver B. D. , Souter R. A. 
Published: July 2008

Timber inventory data is the basis for many monetary transactions related to timber and timberland sale and (or) purchase as well as for development of timber management plans. The value of such data is well known and much appreciated for sale and (or) purchase of standing merchantable timber. Unfortunately, the value of timber inventory data for planning purposes is less well understood. We report on the results of a large simulation study that was undertaken to evaluate the utility and value of timber inventory data for timber management plan development for a typical timberland ownership in the southern United States. Our results indicate that timberland managers are likely producing management plans that do not maximize the profitability of their timberland holdings. Specifically, our results indicate it is likely that timber management organizations that develop timber management plans with stand level data that has a sampling error of 25% are experiencing expected losses in net present value in excess of 170 US$·ha–1 on a large proportion of the acreage found on typical timberland parcels in the southern United States.
A Fixed Point Approach to the Stability of a Functional Equation of the Spiral of Theodorus
Authors: Jung Soon-Mo , Rassias John Michael 
Published: July 2008

AbstractCădariu and Radu applied the fixed point method to the investigation of Cauchy and Jensen functional equations. In this paper, we adopt the idea of Cădariu and Radu to prove the stability of a functional equation of the spiral of Theodorus, "Equation missing"
The Influence of Atmospheric Noise and Uncertainty in Ocean Initial Conditions on the Limit of Predictability in a Coupled GCM
Authors: Stan Cristiana , Kirtman Ben P. 
Published: July 2008

Abstract
The influence of atmospheric stochastic forcing and uncertainty in initial conditions on the limit of predictability of the NCEP Climate Forecast System (CFS) is quantified based on comparisons of idealized identical twin prediction experiments using two different coupling strategies. In the first method, called the interactive ensemble, a single oceanic general circulation model (GCM; the Modular Ocean Model version 3 of GFDL) is coupled to the ensemble average of multiple realizations (in this case six ensemble members) of an atmospheric GCM (NCEP Global Forecast System). In the second method the standard CFS is used. The interactive ensemble is specifically designed to reduce the internal atmospheric dynamic fluctuations that are unrelated to the sea surface temperature anomalies via ensemble averaging at the air–sea interface, whereas in the standard CFS, the atmospheric noise (i.e., stochastic forcing) plays an active role in the evolution of the coupled system. In the identical twin experiments presented here, the perfect model approach is taken, thereby explicitly excluding the impact of model error on the estimate of the limit of predictability. The experimental design and the analysis separately consider how uncertainty in the ocean initial conditions (i.e., initial condition noise) versus uncertainty as the forecast evolves (i.e., noise due to internal dynamics of the atmosphere) impact estimates of the limit of predictability. Estimates of the limit of predictability are based on both deterministic measures (ensemble spread and root-mean-square error) and probabilistic measures (relative operating characteristics). The analysis examines both oceanic and atmospheric variables in the tropical Pacific. The overarching result is that noise in the initial condition is the primary factor limiting predictability, whereas noise as the forecast evolves is of secondary importance.
Quantifying Climate Feedbacks Using Radiative Kernels
Authors: Soden Brian J. , Held Isaac M. , Colman Robert , Shell Karen M. , Kiehl Jeffrey T. , Shields Christine A. 
Published: July 2008

Abstract
The extent to which the climate will change due to an external forcing depends largely on radiative feedbacks, which act to amplify or damp the surface temperature response. There are a variety of issues that complicate the analysis of radiative feedbacks in global climate models, resulting in some confusion regarding their strengths and distributions. In this paper, the authors present a method for quantifying climate feedbacks based on “radiative kernels” that describe the differential response of the top-of-atmosphere radiative fluxes to incremental changes in the feedback variables. The use of radiative kernels enables one to decompose the feedback into one factor that depends on the radiative transfer algorithm and the unperturbed climate state and a second factor that arises from the climate response of the feedback variables. Such decomposition facilitates an understanding of the spatial characteristics of the feedbacks and the causes of intermodel differences. This technique provides a simple and accurate way to compare feedbacks across different models using a consistent methodology. Cloud feedbacks cannot be evaluated directly from a cloud radiative kernel because of strong nonlinearities, but they can be estimated from the change in cloud forcing and the difference between the full-sky and clear-sky kernels. The authors construct maps to illustrate the regional structure of the feedbacks and compare results obtained using three different model kernels to demonstrate the robustness of the methodology. The results confirm that models typically generate globally averaged cloud feedbacks that are substantially positive or near neutral, unlike the change in cloud forcing itself, which is as often negative as positive.
A Conjecture on the Role of Bottom-Enhanced Diapycnal Mixing in the Parameterization of Geostrophic Eddies
Authors: Marshall David P. , Naveira Garabato Alberto C. 
Published: July 2008

AbstractThe parameterization of geostrophic eddies represents a large sink of energy in most ocean models, yet the ultimate fate of this eddy energy in the ocean remains unclear. The authors conjecture that a significant fraction of the eddy energy may be transferred to internal lee waves and oscillations over rough bottom topography, leading to bottom-enhanced diapycnal mixing. A range of circumstantial evidence in support of this conjecture is presented and discussed. The authors further propose a modification to the Gent and McWilliams eddy parameterization to account for the bottom-enhanced diapycnal mixing.
The Influence of Whitecapping Waves on the Vertical Structure of Turbulence in a Shallow Estuarine Embayment
Authors: Jones Nicole L. , Monismith Stephen G. 
Published: July 2008

AbstractThe vertical distribution of the turbulent kinetic energy dissipation rate was measured using an array of four acoustic Doppler velocimeters in the shallow embayment of Grizzly Bay, San Francisco Bay, California. Owing to the combination of wind and tide forcing in this shallow system, the surface and bottom boundary layers overlapped. Whitecapping waves were generated for a significant spectral peak steepness greater than 0.05 or above a wind speed of 3 m s−1. Under conditions of whitecapping waves, the turbulent kinetic energy dissipation rate in the upper portion of the water column was greatly enhanced, relative to the predictions of wind stress wall-layer theory. Instead, the dissipation followed a modified deep-water breaking-wave scaling. Near the bed (bottom 10% of the water column), the dissipation measurements were either equal to or less than that predicted by wall-layer theory. Stratification due to concentration gradients in suspended sediment was identified as the likely cause for these periods of production–dissipation imbalance close to the bed. During 50% of the well-mixed conditions experienced in the month-long experiment, whitecapping waves provided the dominant source of turbulent kinetic energy over 90% or more of the water column.
Mean Flow in the Gulf of Mexico
Authors: Sturges Wilton , Kenyon Kern E. 
Published: July 2008

Abstract
Several independent data sources suggest that there is a net upper-layer mass flux O(3 Sv) (Sv ≡ 106 m3 s−1) to the west in the central Gulf of Mexico, even though the western gulf is a closed basin. A plausible explanation is that this net flux is pumped downward by the convergent wind-driven Ekman pumping, as is typical of all midlatitude anticlyclonic gyres. The downward flux can follow isopycnals to depths O(500–600 m) and deeper by eddy mixing; a mechanism for forcing deep water to the south through the Yucatan Channel is provided by the intrusion and ring-shedding cycle of the Loop Current. Potential vorticity maps show that a deep flow from the western gulf back to the Yucatan Channel is likely.
An Observational Study of Convection Initiation on 12 June 2002 during IHOP_2002
Authors: Weckwerth Tammy M. , Murphey Hanne V. , Flamant Cyrille , Goldstein Janine , Pettet Crystalyne R. 
Published: July 2008

Abstract
The International H2O Project (IHOP_2002) was designed to sample the three-dimensional time-varying moisture field to better understand convective processes. Numerous research and operational water vapor measuring systems and retrievals, via in situ and remote sensing techniques, were operated in the U.S. Southern Great Plains from 13 May to 25 June 2002. This was done in combination with more traditional observations of wind and temperature. Convection initiation (CI) sampling strategies were designed to optimally employ the array of ground-based and airborne sensors to observe the processes leading to the development of deep, moist convection. This case study examines several clear-air features and their impact on CI on 12 June 2002. The supercells that developed produced damaging winds and hail. The clear-air, preconvective features included (i) a mesoscale low pressure region, (ii) a dryline, (iii) an old outflow boundary, (iv) the intersection of (ii) and (iii), (v) internal gravity waves, and (vi) horizontal convective rolls.
A unique combination of instruments was positioned to sample the preconvective environment on 12 June 2002. The Lidar pour l’Etude des Interactions Aérosols Nuages Dynamique Rayonnement et du Cycle de l’Eau (LEANDRE II) water vapor differential absorption lidar (DIAL), the airborne Electra Doppler Radar (ELDORA), and the Navy Research Laboratory (NRL) P3 aircraft in situ measurements provided information on the moisture and vertical velocity distribution within the boundary layer. Radiosondes, dropsondes, wind profilers, and an Atmospheric Emitted Radiance Interferometer (AERI) provided temperature, moisture, and wind profiling information. Although other ground-based sensors (i.e., S-band dual-polarization Doppler radar, Mobile Integrated Profiling System) were 50–150 km west of the CI area, they were useful for illustrating the boundary layer kinematics and reflectivity fields.
Results suggest that the mesolow and mesoscale boundaries, respectively, acted to enhance the low-level moisture advection and convergence in the CI region. While internal gravity waves were present and appeared to modulate water vapor along the old outflow boundary, they did not play an obvious role in CI in this case. Horizontal convective rolls were observed beneath the new storms that initiated and may have helped to focus the CI in this case.