bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of emissions and transport of CFCs using surface observations and their seasonal cycles and the GEOS CCM simulation with emissions‐based forcing
Authors: Liang Qing , Stolarski Richard S. , Douglass Anne R. , Newman Paul A. , Nielsen J. Eric
Published: July 2008

Levels of ozone depleting substances (ODSs) in our atmosphere are determined by production, emission, and loss processes. However, atmospheric models are forced by the specified mixing ratios of these ODSs rather than the more fundamental emissions‐based forcing. To more accurately represent the physics and chemistry of climate change on atmospheric circulation and ODSs, and therefore future ozone recovery, it is desirable to switch from the current highly constrained mixing‐ratio‐based forcing to emissions‐based forcing in general circulation models (GCMs). As a first step of this model transition, we have conducted a 45‐year (1960–2005) emissions‐based simulation of the three primary chlorofluorocarbons (CFC‐11, ‐12, ‐113) using the GEOS coupled chemistry‐climate model (CCM). The simulated CFC concentrations and their seasonal cycles are compared with AGAGE and NOAA‐GMD observations to evaluate emissions and atmospheric transport. The simulated CFC‐12 agrees well with the observations, indicating a good estimate of emission and atmospheric loss. The simulated CFC‐11 and CFC‐113 shows high biases due to overestimate of emissions. Using tagged CFC tracers to track recent surface emissions and aged air masses transported downward from the stratosphere separately, we quantify the relative contribution of stratosphere‐troposphere exchange (STE) and tropospheric transport to the seasonal cycles of CFCs in the lower troposphere. The seasonal cycles of CFCs in the lower troposphere are dominated by tropospheric transport of recent emissions during 1985–1994. The 1995–1999 period marks the transition period when variations due to fresh emissions and STE become equally important. Seasonal cycles of CFCs at most surface sites in the 2000–2004 period are dominated by STE. Seasonal cycles of CFCs due to STE show a late winter/early spring maximum and a summer/fall minimum. Seasonality of the tropospheric transport component at individual stations is governed by seasonal transport variations of fresh emissions from the polluted regions.
Overlap of fractional cloud for radiation calculations in GCMs: A global analysis using CloudSat and CALIPSO data
Authors: Barker Howard W.
Published: July 2008

Assumptions made by global climate models (GCMs) regarding vertical overlap of fractional amounts of clouds have significant impacts on simulated radiation budgets. A global survey of fractional cloud overlap properties was performed using 2 months of cloud mask data derived from CloudSat‐CALIPSO satellite measurements. Cloud overlap was diagnosed as a combination of maximum and random overlap and characterized by vertically constant decorrelation length cf*. Typically, clouds overlap between maximum and random with smallest cf* (medians → 0 km) associated with small total cloud amounts , while the largest cf* (medians ∼3 km) tend to occur at near 0.7. Global median cf* is ∼2 km with a slight tendency for largest values in the tropics and polar regions during winter. By crudely excising near‐surface precipitation from cloud mask data, cf* were reduced by typically <1 km. Median values of cf* when Sun is down exceed those when Sun is up by almost 1 km when cloud masks are based on radar and lidar data; use of radar only shows minimal diurnal variation but significantly larger cf*. This suggests that sunup inferences of cf* might be biased low by solar noise in lidar data. Cloud mask cross‐section lengths L of 50, 100, 200, 500, and 1000 km were considered. Distributions of cf* are mildly sensitive to L thus suggesting the convenient possibility that a GCM parametrization of cf* might be resolution‐independent over a wide range of resolutions. Simple parametrization of cf* might be possible if excessive random noise in , and hence radiative fluxes, can be tolerated. Using just cloud mask data and assuming a global mean shortwave cloud radiative effect of −45 W m−2, top of atmosphere shortwave radiative sensitivity to cf* was estimated at 2 to 3 W m−2 km−1.
Interannual variations of middle atmospheric temperature as measured by the JPL lidar at Mauna Loa Observatory, Hawaii (19.5°N, 155.6°W)
Authors: Li Tao , Leblanc Thierry , McDermid I. Stuart
Published: July 2008

The Jet Propulsion Laboratory Rayleigh‐Raman lidar at Mauna Loa Observatory (MLO), Hawaii (19.5°N, 155.6°W) has been measuring atmospheric temperature vertical profiles routinely since 1993. Linear regression analysis was applied to the 13.5‐yearlong (January 1994 to June 2007) deseasonalized monthly mean lidar temperature time series for each 1‐km altitude bin between 15 and 85 km. The regression analysis included components representing the Quasi‐Biennial Oscillation (QBO), El Niño‐Southern Oscillation (ENSO), and the 11‐year solar cycle. Where overlapping was possible, the results were compared to those obtained from the twice‐daily National Weather Service (NWS) radiosonde profiles at Hilo (5–30 km) located 60 km east‐north‐east of the lidar site, and the four‐times‐daily temperature analysis of the European Centre for Medium Range Weather Forecast (ECMWF). The analysis revealed the dominance of the QBO (1–3 K) in the stratosphere and mesosphere, and a strong winter signature of ENSO in the troposphere and lowermost stratosphere (∼1.5 K/MEI). Additionally, and for the first time, a statistically significant signature of ENSO was observed in the mesosphere, consistent with the findings of recent model simulations. The annual mean response to the solar cycle shows two statistically significant maxima of ∼1.3 K/100 F10.7 units at 35 and 55 km. The temperature responses to QBO, ENSO, and solar cycle are all maximized in winter. Comparisons with the global ECMWF temperature analysis clearly showed that the middle atmosphere above MLO is under a subtropical/extratropical regime, i.e., generally out‐of‐phase with that in the equatorial regions, and synchronized to the northern hemisphere winter/spring.
Quasi‐biennial modulation of the Northern Hemisphere tropopause height and temperature
Authors: Ribera P. , Peña‐Ortiz C. , Añel J. A. , Gimeno L. , de la Torre L. , Gallego D.
Published: July 2008

The influence of the quasi‐biennial oscillation (QBO) on the tropopause pressure and temperature is studied through the application of the multitaper‐singular value decomposition method (MTM‐SVD). Reanalysis data (ERA‐40) from the European Centre for Medium‐Range Weather Forecasts (ECMWF) and radiosonde data from the Integrated Global Radiosonde Archive (IGRA) covering the period 1979–1999 are used. The results show a strong response of the height and temperature of the tropopause to the QBO not limited to the equatorial latitudes but affecting the entire Northern Hemisphere. A cooling (warming) of the tropopause temperature over polar (equatorial) latitudes during a QBO positive phase is observed, being particularly noticeable over polar latitudes. The anomalies in the tropopause height confirm these results, with the tropopause being at higher (lower) levels in polar (equatorial) latitudes during QBO positive phase. Results for the QBO negative phase are of opposite sign. We also found that the results obtained using raw radiosonde data and reanalysis are in very good agreement. Finally, the evolution of the mass stream function through a QBO cycle is used to justify the differences observed in the evolution of the tropopause characteristics at low and high latitudes through the QBO cycle.
A generic, process‐based model of microbial pollution in aquatic systems
Authors: Hipsey Matthew R. , Antenucci Jason P. , Brookes Justin D.
Published: July 2008

Based on a comprehensive synthesis of data available within the literature, a new process‐based model of microbial pollution is presented, which is applicable for surface and coastal waters. The model is based on a generic set of parameterisations that describe the dynamics of most protozoan, bacterial and viral organisms of interest, including pathogens and microbial indicator organisms. The parameterisations dynamically account for the effects of temperature, salinity, pH, dissolved oxygen, sunlight, nutrients and turbidity on the growth and mortality of enteric organisms. Parameters for a range of organisms are also presented which are based on collation of literature data. The model has been implemented within an aquatic ecology model, Computational Aquatic Ecosystem Dynamics Model (CAEDYM), which can couple to multidimensional hydrodynamic models. Without adjustment of the literature derived parameter values, a 3‐D implementation is validated against observed data from three freshwater systems that differ in their climatic zone, trophic status and operation. The simulations highlight the spatial and temporal variability that may be encountered by operators. Additionally, large differences in the fate and distribution of different species originate from variable rates of growth, mortality and sedimentation and it is emphasized that the use of surrogates for quantifying risk is problematic. The model can be used to help design targeted monitoring programs, explore differences between species, and to support real‐time decision‐making. Areas where insufficient understanding and data exist are discussed.
Ionospheric ULF oscillations driven from above Arecibo
Authors: Dyrud L. P. , Behnke R. , Kepko E. L. , Sulzer M. , Zafke S.
Published: July 2008

Understanding the coupling between the surface of the sun, the solar corona, the solar wind, the Earth's magnetosphere and ionosphere is a major focus of today's space research. Over 20 years ago, detailed observations of the ionospheric electron density at Arecibo revealed short period fluctuations (3 minutes), but their cause was never determined. Also, in the past 20 years a number of papers have reported observations of discrete (1–5 mHz) waves at persistent “magic frequencies” in magnetometer data and radar observations of ionospheric drift. Such observations have been generally interpreted as standing waves excited by magnetospheric cavity compressional modes. This assertion has been recently challenged by suggestions that these magic frequencies are not standing waves, but are due to inherent oscillations in the solar wind. Here we show that a subset of discrete 1.7 mHz oscillations in the solar wind plasma density are likely transmitted via a passive magnetospheric oscillation, and are observed as small amplitude (0.1%), discrete 1.7 mHz oscillations in the ionospheric plasma line using the extremely sensitive ionospheric measurements over Arecibo, Puerto Rico. We present over three hours of data using the electron plasma line component of the Arecibo radar incoherent scatter radar spectrum, solar wind number density from the WIND satellite, and magnetic field from the GOES satellite. This paper demonstrates a link between the solar wind and low latitude ionosphere.
A solar terminator wave in thermosphere neutral densities measured by the CHAMP satellite
Authors: Forbes Jeffrey M. , Bruinsma Sean L. , Miyoshi Yasunobu , Fujiwara Hitoshi
Published: July 2008

A solar terminator wave is discovered in neutral thermosphere densities. The data originate from the accelerometer experiment on the CHAMP satellite between 2001 and 2007. During solar minimum conditions the phase fronts of the dusk terminator wave during Northern Hemisphere summer extend from about −60° to almost +30° latitude, at an angle of about 30° with respect to the terminator. The density amplitudes are of order ±3–6%, and the horizontal wavelength is of order 3,000 km. The dusk terminator wave is generally more well‐defined than that near dawn, is more prominent during solar minimum than solar maximum, and during solstice as opposed to equinox. This wave is also found in similarly‐analyzed output from the Kyushu University General Circulation Model that extends from the surface to the exobase. At solar minimum the model wave amplitude is similar to that observed, but with a horizontal wavelength close to 2,000 km. Analytic theory predicts a typical horizontal wavelength of 1,000 km. While there have been several reports of ionospheric waves in connection with the solar terminator, this appears to be the first such observation in the neutral thermosphere. In addition, the orientations of the dawn and dusk terminator waves are such that the maximum equatorial density perturbation occurs near midnight; therefore, some previous observations of the so‐called “midnight temperature maximum” may contain contributions attributable to the terminator wave.
Tibetan Plateau warming and precipitation changes in East Asia
Authors: Wang Bin , Bao Qing , Hoskins Brian , Wu Guoxiong , Liu Yimin
Published: July 2008

Observational evidence presented here indicates that the surface temperatures on the Tibetan Plateau (TP) have increased by about 1.8°C over the past 50 years. The precipitation pattern that is projected as a result of this warming resembles the leading pattern of precipitation variations in East Asia (EA). Numerical experiments with atmospheric general circulation models show that atmospheric heating induced by the rising TP temperatures can enhance East Asian subtropical frontal rainfall. The mechanism of the linkage is found to be through two distinct Rossby wave trains and the isentropic uplift to the east of the TP, which deform the western Pacific Subtropical High and enhance moisture convergence toward the EA subtropical front. The model calculations suggest that the past changes in TP temperatures and EA summer rainfall may be linked, and that projected future increases in TP temperatures may lead to further enhanced summer frontal rainfall in EA region.
Multi‐instrument analysis of electron populations in Saturn's magnetosphere
Authors: Schippers P. , Blanc M. , André N. , Dandouras I. , Lewis G. R. , Gilbert L. K. , Persoon A. M. , Krupp N. , Gurnett D. A. , Coates A. J. , Krimigis S. M. , Young D. T. , Dougherty M. K.
Published: July 2008

We analyze the radial distribution of electron populations inside 20 Rs in Saturn's magnetosphere, and we calculate moments for these populations by a forward modeling method using composite spectra produced by the CAPS/ELS (0.6 eV to 26 keV) and the MIMI/LEMMS (15 keV to 10 MeV) instruments on board Cassini. We first calculate and harmonize both data sets in physical units and apply corrections taking into account biases introduced by spacecraft interaction with the magnetospheric environment. We then test different bimodal isotropic electron distribution models, deciding on a model with two kappa distributions. We adjust our isotropic model to the flux composite spectra with a least square method to produce three sets of fluid parameters (density, temperature, spectral index) per electron population. The radial profiles are then analyzed, revealing a relevant boundary at 9 Rs in both thermal and suprathermal electron populations. Observed discontinuities in the moment profiles (sudden drop‐off in cold density profile outside 9 Rs, hot electrons drop‐off inside 9 Rs) coincide with the known outer edge of Saturn's neutral OH cloud. Farther out, thermal electrons disappear completely beyond 15 Rs while suprathermal electrons are still observed in the middle and outer magnetosphere.
Ionospheric disturbances caused by SGR 1900+14 giant gamma ray flare in 1998: Constraints on the energy spectrum of the flare
Authors: Tanaka Y. T. , Terasawa T. , Yoshida M. , Horie T. , Hayakawa M.
Published: July 2008

On 27 August 1998, the Soft Gamma Ray Repeater (SGR) 1900+14, which is an exotic neutron star located near the Galactic Center, produced a giant flare. Gamma rays from the giant flare unusually ionized the lower ionosphere, and the ionospheric disturbance was detected as a large‐amplitude change of the VLF signal whose propagation distance is relatively short (870 km). The peak flux of the flare was so huge that it saturated all the gamma ray detectors on the spacecraft; consequently, the flux and the spectrum during the most intense period was poorly determined. Tanaka et al. (2007) have recently derived the accurate peak flux of the flare from the Geotail data. By means of model calculations based on this accurate estimation and their comparisons with the short‐distance VLF data, we have found that the spectrum during the most intense period was one temperature (kT = 240 keV) optically thin thermal Bremsstrahlung (OTTB). This result provides us with a clue to reveal the emission and triggering mechanisms of the giant flare.
Preventing Excessive Weight Gain in Adolescents: Interpersonal Psychotherapy for Binge Eating
Authors: Tanofsky‐Kraff Marian , Wilfley Denise E. , Young Jami F. , Mufson Laura , Yanovski Susan Z. , Glasofer Deborah R. , Salaita Christine G.
Published: July 2008

The most prevalent disordered eating pattern described in overweight youth is loss of control (LOC) eating, during which individuals experience an inability to control the type or amount of food they consume. LOC eating is associated cross‐sectionally with greater adiposity in children and adolescents and seems to predispose youth to gain weight or body fat above that expected during normal growth, thus likely contributing to obesity in susceptible individuals. No prior studies have examined whether LOC eating can be decreased by interventions in children or adolescents without full‐syndrome eating disorders or whether programs reducing LOC eating prevent inappropriate weight gain attributable to LOC eating. Interpersonal psychotherapy, a form of therapy that was designed to treat depression and has been adapted for the treatment of eating disorders, has shown efficacy in reducing binge eating episodes and inducing weight stabilization among adults diagnosed with binge eating disorder. In this paper, we propose a theoretical model of excessive weight gain in adolescents at high risk for adult obesity who engage in LOC eating and associated overeating patterns. A rationale is provided for interpersonal psychotherapy as an intervention to slow the trajectory of weight gain in at‐risk youth, with the aim of preventing or ameliorating obesity in adulthood.
Interventions to Prevent or Treat Obesity in Preschool Children: A Review of Evaluated Programs
Authors: Bluford Dontrell A.A. , Sherry Bettylou , Scanlon Kelley S.
Published: July 2008

Objective: To identify effective programs to prevent or treat overweight among 2‐ to <6‐year‐old children.

Research Methods and Procedures: We searched six databases to identify evaluated intervention programs assessing changes in weight status or body fat and systematically summarized study attributes and outcomes.

Results: Four of the seven studies (two intervention, two prevention) documented significant reductions in weight status or body fat. Among these, three sustained reductions at 1 or 2 years after program initiation, three incorporated a framework/theory, two actively and one passively involved parents, three included multicomponent strategies, and all four monitored behavioral changes. Of the three (prevention) studies that did not show reduction in weight or fat status, all performed assessments between 4 and 9 months after program initiation, and one used a multicomponent strategy. Other significant changes reported were reductions in television viewing, cholesterol, and parental restriction of child feeding.

Discussion: The paucity of studies limits our ability to generalize findings. Among the available studies, multicomponent programs with 1‐ to 2‐year follow‐up in clinics or child care settings were successful in their impact on weight; they were likely enhanced by parental involvement. Both treatment programs and two of five prevention programs reduced weight/fat status. Our review highlights the need to evaluate more programs, advocate for use of a framework/behavioral theory and objective behavioral measures, further examine the impact of involving parents and the impact of intervention duration and follow‐up time, strengthen prevention programs, and further evaluate successful programs in other settings and among other racial/ethnic groups.
Metabolic and Behavioral Compensatory Responses to Exercise Interventions: Barriers to Weight Loss
Authors: King Neil A. , Caudwell Phillipa , Hopkins Mark , Byrne Nuala M. , Colley Rachel , Hills Andrew P. , Stubbs James R. , Blundell John E.
Published: July 2008

An activity‐induced increase in energy expenditure theoretically disturbs energy balance (EB) by creating an acute energy deficit. Compensatory responses could influence the weight loss associated with the energy deficit. Individual variability in compensation for perturbations in EB could partly explain why some individuals fail to lose weight with exercise. It is accepted that the regulatory system will readily defend impositions that promote a negative EB. Therefore, a criticism of exercise interventions is that they will be ineffective and futile methods of weight control because the acute energy deficit is counteracted. Compensation for exercise‐induced energy deficits can be categorized into behavioral or metabolic responses and automatic or volitional. An automatic compensatory response is a biological inevitability and considered to be obligatory. An automatic compensatory response is typically a metabolic consequence (e.g., reduced resting metabolic rate) of a negative EB. In contrast, a volitional compensatory response tends to be deliberate and behavioral, which the individual intentionally performs (e.g., increased snack intake). The purpose of this review is to highlight the various metabolic and behavioral compensatory responses that could reduce the effectiveness of exercise and explain why some individuals experience a lower than expected weight loss. We propose that the extent and degree of compensation will vary between individuals. That is, some individuals will be predisposed to compensatory responses that render them resistant to the weight loss benefits theoretically associated with an exercise‐induced increase in energy expenditure. Therefore, given the inter‐individual variability in behavioral and metabolic compensatory responses, exercise prescriptions might be more effective if tailored to suit individuals.
The F Box Protein S Phase Kinase‐associated Protein 2 Regulates Adipose Mass and Adipocyte Number in Vivo
Authors: Cooke Paul S. , Holsberger Denise R. , Cimafranca Melissa A. , Meling Daryl D. , Beals Charity M. , Nakayama Keiko , Nakayama Keiichi I. , Kiyokawa Hiroaki
Published: July 2008

Objective: The etiology of some obesity may involve adipocyte hyperplasia. However, the role of adipocyte number in establishing adipose mass is unclear. Cyclin‐dependent kinase inhibitor p27 regulates activity of cyclin/cyclin‐dependent kinase complexes responsible for cell cycle progression. This protein is critical for establishing adult adipocyte number, and p27 knockout increases adult adipocyte number. The SCF (for Skp1‐Cullin‐F‐box protein) complex targets proteins such as p27 for ubiquitin‐proteosome degradation; the F box protein S phase kinase‐associated protein 2 (Skp2), a component of the SCF complex, specifically recognizes p27 for degradation. We used Skp2 knockout (Skp2−/−) mice to test whether Skp2 loss decreased adipose mass and adipocyte number.

Research Methods and Procedures: We measured body weight, adipose mass, adipocyte diameter and number, and glucose tolerance in wild‐type (WT), Skp2−/−, and p27−/−Skp2−/− mice. Mouse embryo fibroblasts (MEFs) from WT and Skp2−/− fetuses were differentiated to determine whether Skp2 directly affected adipogenesis.

Results: Skp2−/− mice had a 50% decrease in both subcutaneous and visceral fat pad mass and adipocyte number; these decreases exceeded those in body weight, kidney, or muscle. To test the hypothesis that Skp2 effects on adipocyte number involved p27 accumulation, we used p27−/−Skp2−/− double knockout mice. The Skp2−/− decrements in adipocyte number and fat pad mass were totally reversed in p27−/−Skp2−/− mice. Adipogenesis was inhibited in MEFs from Skp2−/− vs. WT mice, and this inhibition was absent in MEFs from p27−/−Skp2−/− mice.

Discussion: Our results indicate that Skp2 regulates adipogenesis and ultimate adipocyte number in vivo; thus, Skp2 may contribute to obesity involving adipocyte hyperplasia.
Sleep Apnea Is Induced by a High‐fat Diet and Reversed and Prevented by Metformin in Non‐obese Rats
Authors: Ramadan Wiâm , Dewasmes Gérard , Petitjean Michel , Wiernsperger Nicolas , Delanaud Stéphane , Geloen Alain , Libert Jean‐Pierre
Published: July 2008

Objective: We assessed the relationship between a high‐fat (HF) diet and central apnea during rapid eye movement and non‐rapid eye movement sleep stages by recording ventilatory parameters in 28 non‐obese rats in which insulin resistance had been induced by an HF diet. We also studied whether metformin (an anti‐hyperglycemic drug frequently used to treat insulin resistance) could reverse sleep apnea or prevent its occurrence in this experimental paradigm.

Research Methods and Procedures: Rats were fed with a standard diet (10 rats), an HF diet (8 rats), or an HF diet concomitantly with metformin treatment (10 rats). Each animal was instrumented for electroencephalographic and electromyographic recording. After 3 weeks, ventilatory parameters during sleep were recorded with a body plethysmograph. All rats were treated with metformin for 1 week, after which time the ventilatory measurements were measured again.

Results: Our results showed that the three groups of animals did not differ in terms of body growth over the entire experimental period. The HF diet did not modify sleep structure or minute ventilation in the different sleep stages. A great increase (+266 ± 48%) in central apnea frequency was observed in insulin‐resistant rats. This was explained by an increase in both post‐sigh (+195 ± 35%) and spontaneous apnea (+437 ± 65%) in the different sleep stages. These increases were suppressed by metformin treatment.

Discussion: Insulin resistance induced by the HF diet could be the promoter of sleep apnea in non‐obese rats. Metformin is an efficient curative and preventive treatment for sleep apnea, suggesting that insulin resistance modifies the ventilatory drive independently of obesity.
Biliopancreatic Diversion Reduces QT Interval and Dispersion in Severely Obese Patients
Authors: Bezante Gian Paolo , Scopinaro Alice , Papadia Francesco , Campostano Adele , Camerini Giovanni , Marinari Giuseppe , Balbi Manrico , Adami Gian Franco , Barsotti Antonio , Scopinaro Nicola
Published: July 2008

Objectives: The objectives were to evaluate QT interval (QTc) and QT‐interval dispersion (QTd) in severely obese individuals and to determine the effects of biliopancreatic diversion (BPD) and weight loss after BPD on ventricular repolarization parameters.

Background: People with severe obesity (SO) have a 50% to 100% increased risk of death associated with a 1.6‐fold increased risk of sudden death. BPD surgery induces rapid and considerable weight loss through severe lipid malabsorption, thus achieving long‐term weight control.

Research Methods and Procedures: A total of 85 subjects with SO (age, 42 ± 12 years; 66 females; mean body weight, 120 ± 29 kg; BMI, 45 ± 11 kg/m2) of 330 who had a bariatric surgical consultation between January 2001 and July 2002 were enrolled. Inclusion criteria were sinus rhythm, unremarkable 12 leads surface electrocardiogram, no atrioventricular blocks and/or bundle branch blocks, normal serum electrolyte profile, and no medical therapies exerting known effects on QTc. Exclusion criteria were previous diagnosis of coronary artery disease, known cardiovascular disease, atrial fibrillation or any other known cardiac arrhythmias, cancer, or renal dysfunction.

Results: A total of 86% of patients had QTc >440 ms and/or QTd >60 ms. Subjects with SO showed a mean maximum QTc of 446 ± 28 ms and a mean QTd of 52 ± 20 ms. A close correlation was found between QTc and QTd (p < 0.0001; R2 = 0.33). One month after BPD, mean QTc was 420 ms and remained stable at follow‐up; QTd was 32 ms at 1 and 6 months and became 35 ms at 1 year.

Conclusions: Ventricular repolarization abnormalities are significantly increased in subjects with SO. Reduction of QT abnormalities after BPD is independent of weight loss and is caused by the 100% reduction of glucose plasma shortly after surgery. This effect may be related to surgical interruption of the entero‐insular axis.
Effect of Increased Dairy Consumption on Appetitive Ratings and Food Intake
Authors: Hollis James H. , Mattes Richard D.
Published: July 2008

Objective: The influence of dairy product consumption on food intake and appetitive sensations was explored in a cross‐over design study with individuals who were habitually low (<1 serving/d) or high (>3 servings/d) dairy consumers.

Research Methods and Procedures: Fifty‐eight participants were required to eat one portion of dairy each day (low dairy) or three portions of dairy each day (high dairy) for 7 days. After a 7‐day washout period, the opposite treatment condition was completed. Food intake and appetitive ratings were measured on each day of the treatment periods.

Results: During the high‐dairy period, participants consumed 209 kcal/d more than during the low dairy period (p < 0.05). There were no significant differences in subjective appetite ratings. Habitual dairy use did not influence either the appetitive or dietary findings.

Discussion: These data indicate that increasing dairy consumption may lead to increased energy intake, which could potentially cause weight gain.
Sedentary Behavior, Recreational Physical Activity, and 7‐Year Weight Gain among Postmenopausal U.S. Women
Authors: Blanck Heidi M. , McCullough Marjorie L. , Patel Alpa V. , Gillespie Cathleen , Calle Eugenia E. , Cokkinides Vilma E. , Galuska Deborah A. , Khan Laura Kettel , Serdula Mary K.
Published: July 2008

Objective: To assess the relationship among recreational physical activity (PA), non‐occupational sedentary behavior, and 7‐year weight gain among postmenopausal U.S. women 40 to 69 years old.

Research Methods and Procedures: In 1992 and 1999, 18,583 healthy female participants from the Cancer Prevention Study II Nutrition Cohort completed questionnaires on anthropometric characteristics and lifestyle factors. The associations between recreational PA [in metabolic equivalent (MET) hours per week] and non‐occupational sedentary behavior (in hours per day) at baseline and risk for 7‐year weight gain (5 to 9 or ≥10 vs. ±4 pounds) were assessed using multivariate logistic regression analysis.

Results: Neither PA nor sedentary behavior was associated with a 5‐ to 9‐pound weight gain. Among women who were not overweight at baseline (BMI <25.0), the odds of ≥10‐pound weight gain were 12% lower (odds ratio, 0.88; 95% confidence interval, 0.77 to 0.99) for those in the highest category of recreational PA (≥18 MET h/wk) compared with >0 to <4 MET h/wk; odds were 47% higher (odds ratio, 1.47; 95% confidence interval, 1.21 to 1.79) for non‐overweight women who reported ≥6 h/d of non‐occupational sedentary behavior compared with <3 h/d. Neither PA nor sedentary behavior were associated with risk of ≥10‐pound weight gain weight among women who were overweight at baseline (BMI ≥25.0).

Discussion: Both recreational PA and non‐occupational sedentary behavior independently predicted risk of ≥10‐pound weight gain among postmenopausal women who were not overweight at baseline. Public health messages to prevent weight gain among normal‐weight postmenopausal women may need to focus on decreasing time spent in sedentary behaviors and increasing the amount of time spent on PA.
Effects of Palmitate and Oleate on the Respiratory Quotient During Acute Feeding
Authors: Kien C. Lawrence , Bunn Janice Y.
Published: July 2008

Objective: Using tracers, we showed, over 9 hours, that palmitic acid (PA) is oxidized at a lower rate than oleic acid (OA). Our subsequent clinical trial showed that enriching the diet for 28 days with PA, relative to OA, lowered fatty acid (FA) oxidation. However, because this conclusion was based on indirect calorimetry for 7 hours after a test meal, transient differences in the kinetics of oxidation of OA and PA could explain these results. Thus, we hypothesized that increasing PA vs. OA would decrease FA oxidation during the first day of feeding the diets.

Research Methods and Procedures: A double‐masked trial was conducted in 20 adults, who, after a baseline diet, were randomized to one of two experimental formula diets: high (HI) OA (PA = 1.7% kcal, OA = 31.4% kcal; N = 11) or HI PA (PA = 16.8% kcal, OA = 16.4% kcal; N = 9). Respiratory quotient (RQ) was measured over the first 14 hours of feeding the experimental diets (7:00 am to 9:00 pm). To determine whether these subjects were representative of the subjects in the previous trial, we assessed RQ 28 days after beginning either diet.

Results: During the first 14 hours of feeding the diets, time (p = 0.026) but not diet group had an effect on the difference between the RQ post‐feeding and the fasting pre‐value. However, RQ in the fed state was significantly higher in the HI PA group after 28 days of feeding.

Discussion: Chronically increasing dietary PA for 28 days, but not acute meal feeding, lowers total FA oxidation.
Activity, Inactivity, and Screen Time in Relation to Weight and Fatness Over Adolescence in Girls
Authors: Must Aviva , Bandini Linda G. , Tybor David J. , Phillips Sarah M. , Naumova Elena N. , Dietz William H.
Published: July 2008

Objective: The impact of activity and inactivity on relative weight and fatness change are best evaluated longitudinally. We examined the longitudinal relationship of physical activity, inactivity, and screen time with relative weight status and percentage body fat (%BF) and explored how it differed by parental overweight status.

Research Methods and Procedures: Non‐obese pre‐menarcheal girls (173), 8 to 12 years old, were followed until 4 years post‐menarche. %BF, BMI z‐score, and time spent sleeping, sitting, standing, walking, and in vigorous activity were assessed annually. We developed a physical activity index to reflect time and intensity of activity. Inactivity was defined as the sum of time spent sleeping, sitting, and standing. Screen time was defined as time spent viewing television, videotapes, or playing video games. Parental overweight was defined as at least one parent with BMI > 25.

Results: In separate linear mixed effects models, activity, inactivity, and screen time were unrelated to BMI z‐score longitudinally, with and without accounting for parental overweight. After controlling for parental overweight, activity was inversely related (p < 0.001), and inactivity was directly related (p < 0.035) to increased %BF longitudinally. Screen time was unrelated to %BF change. With stratification for parental overweight, effects of activity and inactivity on %BF were observed only among girls with at least one overweight parent.

Discussion: In this cohort of initially non‐overweight girls, activity and inactivity were related to accrual of BF over adolescence, particularly among children with at least one overweight parent. These results suggest that girls with a family history of overweight represent a target population of high priority for interventions around physical activity and inactivity.
Calcium Supplements in Healthy Children Do Not Affect Weight Gain, Height, or Body Composition
Authors: Winzenberg Tania , Shaw Kelly , Fryer Jayne , Jones Graeme
Published: July 2008

Objective: Calcium intake is a potential factor influencing weight gain and may reduce body weight, but the evidence for this in children is conflicting. The aim of this study was to use data from randomized controlled trials to determine whether calcium supplementation in healthy children affects weight or body composition.

Research Methods and Procedures: This study is a systematic review. We identified potential studies by searching the following electronic bibliographic databases: CENTRAL, MEDLINE, EMBASE, CINAHL, AMED, MANTIS, ISI Web of Science, Food Science and Technology Abstracts, and Human Nutrition up until April 1, 2005 and hand‐searched relevant conference abstracts. Studies were included if they were placebo‐controlled randomized controlled trials of calcium supplementation, with at least 3 months of supplementation, in healthy children and with outcome measures including weight. Meta‐analyses were performed using fixed effects models and weighted mean differences for weight and height and standardized mean differences (SMDs) for body composition measures.

Results: There were no statistically significant effects of calcium supplementation on weight [+0.14 kg; 95% confidence interval (CI), −0.28, +0.57 kg], height (+0.22 cm; 95% CI, −0.30, +0.74 cm), body fat (SMD, +0.04; 95% CI, −0.08, +0.15), or lean mass (SMD, +0.14; 95% CI, −0.03, +0.31).

Discussion: There is no evidence to support the use of calcium supplementation as a public health intervention to reduce weight gain or body fat in healthy children. Although our results do not rule out an effect of dietary supplementation with dairy products on weight gain or body composition, there is little evidence to support this hypothesis.
Recurrent Dieting and Smoking among Finnish Men and Women
Authors: Saarni Suoma E. , Silventoinen Karri , Rissanen Aila , Sarlio‐Lähteenkorva Sirpa , Kaprio Jaakko
Published: July 2008

Objective: To examine the association of smoking with recurrent dieting and BMI among Finnish adults.

Research Methods and Procedures: We used questionnaire data from 1990 on 11,055 subjects from the Finnish Twin Cohort who were 33 to 61 years of age. Multinomial logistic regression analysis was carried out using lifetime dieting as the outcome variable and smoking as the main explanatory variable, adjusted for BMI and age. Twin pairs discordant for dieting and smoking were studied to examine the effect of environmental and genetic factors.

Results: Among women, current smokers [odds ratio (OR), 1.09 to 1.41 at different ages] and former smokers (OR, 1.52 to 2.82) were more likely to have dieted recurrently than never smokers. Among men, current smokers were less likely (OR, 0.69; 95% confidence interval, 0.55, 0.87) and former smokers were more likely (OR, 1.30; 95% confidence interval, 1.05, 1.61) to have dieted recurrently at different ages. The differences between the discordant pairs were consistent with this, although not statistically significant.

Discussion: Recurrent dieting was associated with former smoking in both sexes and with current smoking in women.
The Influence of Weight Loss on Serum Osteoprotegerin Concentration in Obese Perimenopausal Women
Authors: Holecki Michał , Zahorska‐Markiewicz Barbara , Janowska Joanna , Nieszporek Teresa , Wojaczyńska‐Stanek Katarzyna , Żak‐Gołąb Agnieszka , Więcek Andrzej
Published: July 2008

Objective: To assess the influence of weight reduction therapy on serum osteoprotegerin (OPG) concentration in obese patients and compare these results with normal‐weight controls.

Research Methods and Procedures: Forty‐three obese women (BMI, 36.7 ± 4.1 kg/m2; mean age, 50.1 ± 4.5 years) were studied. The control group consisted of 19 normal‐weight women (BMI, 24.2 ± 2.1 kg/m2; mean age, 53.8 ± 5.2 years). In all patients, serum concentrations of OPG, C telopeptide of type I collagen containing the cross‐linking site (CTX), osteocalcin, parathormone, 25‐(OH)‐D3 (vitamin D), and total calcium and phosphorus were assessed before and after a 3‐month weight reduction therapy.

Results: In obese subjects, serum concentrations of OPG, 25‐(OH)‐D3, osteocalcin, total calcium, and phosphorus were significantly lower, and serum concentration of parathormone was significantly higher, before weight reduction therapy in comparison with normal‐weight controls. After weight reduction, a significantly higher serum concentration of 25‐(OH)‐D3 and CTX and significantly lower concentration of OPG were found.

Discussion: Serum concentration of OPG was significantly lower in obese patients in comparison with normal‐weight controls. Weight reduction therapy resulted in further decrease in OPG serum concentrations. Therefore, OPG cannot be treated as a protective factor from bone loss in obese patients.
The Measurement of Resting Metabolic Rate in Preschool Children
Authors: Jackson Diane M. , Pace Lucienne , Speakman John R.
Published: July 2008

Objective: This study examined the repeatability of measuring resting metabolic rate (RMR) in preschool children and the effect of different calculation protocols.

Research Methods and Procedures: Eleven children (4 females and 7 males) participated in the project. They were recruited through advertisements in local schools and community centers. Resting metabolic rate was measured on 3 occasions over a 2‐week period, each after an overnight fast and each lasting ∼20 to 25 minutes. Results were compared using repeated‐measures ANOVA to check for repeatability, and a number of methods of calculating RMR were assessed.

Results: Repeatability of RMR measurements was good (coefficient of variation of replicates, 6.8%), with no significant difference between days of measurement. The lowest RMR measurement was obtained when the first 10 minutes were excluded and periods during which large activity was observed were excluded. This measurement was, on average, 4% lower than averaging the measurements after the first 5 minutes, including body movements.

Discussion: This study suggests that RMR can be measured in preschool children and that the best method for calculating RMR in these subjects is to exclude periods when large body movements occur and the first 10 minutes of the measurement period. Only a single measurement of RMR is needed to obtain a reliable estimate.
11β‐HSD Type 1 Expression in Human Adipose Tissue: Impact of Gender, Obesity, and Fat Localization
Authors: Paulsen Søren Kildeberg , Pedersen Steen Bønløkke , Fisker Sanne , Richelsen Bjørn
Published: July 2008

Objective: Pre‐receptor amplification of glucocorticoids is, in part, determined by the isoenzymes 11β‐hydroxysteroid dehydrogenase (11β‐HSD) type 1 and type 2, interconverting inert cortisone and active cortisol. Increased tissue activity of cortisol may play a part in features of the metabolic syndrome. Our objective was to compare 11β‐HSD1 gene expression in different fat depots (visceral, subcutaneous abdominal, and subcutaneous gluteal) in lean and obese men and women.

Research Methods and Procedures: A cross‐sectional study design was used for healthy patients undergoing minor abdominal surgery (lean men, 10), minor gynecological surgery (lean woman, 10), or gastric banding operations (obese men, 10; and obese women, 10). Gene expressions of 11β‐HSD1 in adipose tissue samples were determined by real‐time reverse transcriptase polymerase chain reaction (RT‐PCR).

Results: Lean women had lower 11β‐HSD1 gene expression in subcutaneous adipose tissue compared with men (62% lower, p < 0.01), whereas no significant difference was found between obese men and women. 11β‐HSD1 mRNA in human adipose tissue was higher in obese subjects compared with lean subjects in both women and men and in both subcutaneous and visceral adipose tissue. No difference in mRNA expression of 11β‐HSD1 between visceral and subcutaneous adipose tissue or between subcutaneous adipose tissue from different depots was found.

Conclusions: 11β‐HSD1 in adipose tissue is increased in obesity in both women and men, and may contribute to the associated metabolic syndrome. As 11β‐HSD1 expression in lean women was found to be significantly lower than in lean males, the up‐regulation associated with obesity may be relatively more devastating in women than in men, and may help explain the higher relative risk of cardiovascular disease in women suffering from the metabolic syndrome.
Macrophage‐Colony Stimulating Factor in Obese Adipose Tissue: Studies With Heterozygous op/+ Mice
Authors: Sugita Satoshi , Kamei Yasutomi , Oka Jun‐Ichiro , Suganami Takayoshi , Ogawa Yoshihiro
Published: July 2008

Objective: We examined the gene expression of macrophage‐colony stimulating factor (M‐CSF) in mice with diet‐induced obesity and in genetically obese mice. We also examined the effect of decreased M‐CSF signaling on the susceptibility to obesity and macrophage recruitment into the adipose tissue of mice.

Research Methods and Procedures: The adipose tissue from mice with diet‐induced obesity, obese KKAy mice, and ob/ob obese mice was used for RNA preparation. Production of M‐CSF and monocyte chemoattractant protein‐1 (MCP‐1) was examined by quantitative real‐time polymerase chain reaction (PCR) and enzyme‐linked immunosorbent assay. The op/+ heterozygous mice, with decreased functional M‐CSF expression, were placed on a high‐fat diet or crossed with KKAy mice to study the susceptibility to obesity. The gene expression of macrophage markers in adipose tissue was examined.

Results: The expression of M‐CSF was not significantly changed in mice on a high‐fat diet or in either type of genetic obesity (KKAy or ob/ob mice). No change in the degree of obesity or macrophage‐related gene expression (F4/80, CD68, and MCP‐1) in the adipose tissue was observed in op/+ mice compared with +/+ control mice, which were either treated with a high‐fat diet or crossed with KKAy mice.

Discussion: This study demonstrated that there was no significant change in the expression of M‐CSF in the adipose tissue from obese mice and only a minor phenotypic change, such as macrophage infiltration, in the adipose tissue from op/+ mice, suggesting that M‐CSF does not play a major role in macrophage recruitment in the adipose tissue of obese mice.
C57BL/6J and A/J Mice Fed a High‐Fat Diet Delineate Components of Metabolic Syndrome
Authors: Gallou‐Kabani Catherine , Vigé Alexandre , Gross Marie‐Sylvie , Rabès Jean‐Pierre , Boileau Catherine , Larue‐Achagiotis Christiane , Tomé Daniel , Jais Jean‐Philippe , Junien Claudine
Published: July 2008

Objective: The aim of this study was to assess the suitability of A/J and C57BL/6J mice of both sexes as models of some components of the human metabolic syndrome (MetS) under nutritional conditions more comparable with the actual worldwide diet responsible for the increased incidence of the MetS.

Research Methods: We fed large cohorts (n = 515) of two strains of mice, A/J and the C57BL/6J, and of both sexes a high‐fat diet (HFD; 60% fat) that, in contrast with most previous reports using saturated fats, was enriched in mono‐ and polyunsaturated fatty acids, thus more closely mimicking most Western diets, or a control diet (10% fat), for 20 weeks.

Results: In sharp contrast to previous reports, weight gain and hyperleptinemia were similar in both strains and sexes. Hyperinsulinemia, glucose tolerance, insulin resistance, and hypercholesterolemia were observed, although with important differences between strains and sexes. A/J males displayed severely impaired glucose tolerance and insulin resistance. However, in contrast with C57BL6/J mice, which displayed overt type 2 diabetes, A/J mice of both sexes remained normoglycemic.

Discussion: With important differences in magnitude and time course, the phenotypic and metabolic characteristics of both strains and both sexes on this HFD demonstrate that these models are very useful for identifying the mechanisms underlying progression or resistance to subsequent type 2 diabetes.