bluuebunny/crossref_metadata_2025 huggingface dataset:
Estimating exchange rate responsiveness to shocks
Authors: Narayan Paresh Kumar
Published: April 2008

The goal of this paper is to examine the importance of permanent and transitory shocks using a more efficient trend‐cycle decomposition of the real exchange rate series. Our main contribution is that in measuring the impact of shocks, we not only impose common trend restrictions but also common cycle restrictions. We later confirm, through a post sample forecasting exercise, the efficiency gains from imposing common cycle restrictions. Our results indicate that permanent shocks are responsible for the bulk of the real exchange rate variations for Japan, Italy, Germany, France, and the UK vis‐à‐vis the US dollar over short horizons. For Canada, however, transitory shocks are dominant over the short horizon. In sum, while for Japan, France, and Italy, around 15% of the variation in real exchange rate is due to transitory shocks, for Canada, Germany and the UK, over 25% of the variations over the short horizon are due to transitory shocks. Thus, we claim that the role of transitory shocks should not be ignored.
Hypoxia in adipose tissue: a basis for the dysregulation of tissue function in obesity?
Authors: Trayhurn Paul , Wang Bohan , Wood I. Stuart
Published: April 2008

White adipose tissue is a key endocrine and secretory organ, releasing multiple adipokines, many of which are linked to inflammation and immunity. During the expansion of adipose tissue mass in obesity there is a major inflammatory response in the tissue with increased expression and release of inflammation-related adipokines, including IL-6, leptin, monocyte chemoattractant protein-1 and TNF-α, together with decreased adiponectin production. We proposed in 2004 (Trayhurn & Wood,Br J Nutr92, 347–355) that inflammation in adipose tissue in obesity is a response to hypoxia in enlarged adipocytes distant from the vasculature. Hypoxia has now been directly demonstrated in adipose tissue of several obese mouse models (ob/ob, KKAy, diet-induced) and molecular studies indicate that the level of the hypoxia-inducible transcription factor, hypoxia-inducible factor-1α, is increased, as is expression of the hypoxia-sensitive marker gene, GLUT1. Cell- culture studies on murine and human adipocytes show that hypoxia (induced by low O2or chemically) leads to stimulation of the expression and secretion of a number of inflammation-related adipokines, including angiopoietin-like protein 4, IL-6, leptin, macrophage migration inhibitory factor and vascular endothelial growth factor. Hypoxia also stimulates the inflammatory response of macrophages and inhibits adipocyte differentiation from preadipocytes. GLUT1 gene expression, protein level and glucose transport by human adipocytes are markedly increased by hypoxia, indicating that low O2tension stimulates glucose utilisation. It is suggested that hypoxia has a pervasive effect on adipocyte metabolism and on overall adipose tissue function, underpinning the inflammatory response in the tissue in obesity and the subsequent development of obesity-associated diseases, particularly type 2 diabetes and the metabolic syndrome.
In a Tradition of Learned Ministry: Wesley's ‘Foxe’
Authors: GREENBERG DEVORAH
Published: April 2008

This examination of John Wesley's emendation and elaboration of John Foxe'sActs and monuments, shows how Wesley constructed Foxe's text and himself within a tradition of learned English ministry. Offering an expanded vision of the role and function of the popularly styled Book of Martyrs, this article combines readings of Wesley's journals and secondary analyses to permit insights into Wesley's relationship with the established Church of England, his intentions in taking up Foxe's text and his conceptions of hierarchy, pastoral duty and ministry. It contradicts scholarly expectation of anti-Catholic impulses behind Foxeian publications and their effects, and encourages a more nuanced appreciation of the contemporary application of the terms ‘Catholic’ and ‘papist’.
Why licensing authorities need to consider the net value of new drugs in assigning review priorities: Addressing the tension between licensing and reimbursement
Authors: McCabe Christopher , Claxton Karl , O'Hagan Anthony
Published: April 2008

Pharmaceutical regulators and healthcare reimbursement authorities operate in different intellectual paradigms and adopt very different decision rules. As a result, drugs that have been licensed are often not available to all patients who could benefit because reimbursement authorities judge that the cost of therapies is greater than the health produced. This finding creates uncertainty for pharmaceutical companies planning their research and development investment, as licensing is no longer a guarantee of market access. In this study, we propose that it would be consistent with the objectives of pharmaceutical regulators to use the Net Benefit Framework of reimbursement authorities to identify those therapies that should be subject to priority review, that it is feasible to do so and that this would have several positive effects for patients, industry, and healthcare systems.
Direct versus indirect comparisons: A summary of the evidence
Authors: Gartlehner Gerald , Moore Charity G.
Published: April 2008

Objectives:The aim of this study was to provide a comprehensive summary and interpretation of the current evidence on the use and validity of statistical methods to conduct indirect comparisons of treatment effects.

Methods:A narrative review was conducted.

Results:Well-conducted methodological studies provide good evidence that adjusted indirect comparisons can lead to results similar to those from direct comparisons. The internal validity of several statistical methods to conduct indirect comparisons, therefore, has been established. Meta-regression, logistic regression, or adjusted indirect comparisons should be the methods of first choice. Unadjusted indirect comparisons are always unacceptable. Deciding whether to combine direct and indirect evidence will be a matter of informed judgment based on the similarities and dissimilarities of populations and interventions. Unverifiable assumptions with respect to the similarity of compared studies and low power are serious limitations of indirect comparisons.

Conclusions:In the absence of sufficient head-to-head evidence, adjusted indirect comparisons can be viewed as additional analytical tools to determine the comparative efficacy and effectiveness of competing interventions. Researchers who use indirect comparisons need to keep the limitations in mind.
Cost-effectiveness and budget impact of adjunctive hyperbaric oxygen therapy for diabetic foot ulcers
Authors: Chuck Anderson W. , Hailey David , Jacobs Philip , Perry Douglas C.
Published: April 2008

Background:Hyperbaric oxygen therapy (HBOT) has been proposed as an adjunct to standard methods of care for diabetic foot ulcers (DFU). Its use may decrease the risk of infection and lower extremity amputations (LEAs). As part of a Canadian assessment, we estimated the cost-effectiveness and budget impact of HBOT in this application.

Methods:We developed a decision model comparing adjunctive HBOT with standard care alone. The population was a 65-year-old cohort with DFU. The time horizon was 12 years taken from a Ministry of Health perspective. The health states were a healed wound with or without a minor LEA, an unhealed wound with no related surgery, and a major LEA. Efficacy data were based on outcomes reported in studies included in a literature review. Cost and capacity needs for treating DFU patients in Canada were estimated using prevalence data from the literature, and cost and utilization data from government records.

Results:The 12-year cost for patients receiving HBOT was CND$40,695 compared with CND$49,786 for standard care alone. Outcomes were 3.64 quality-adjusted life-years (QALYs) for those receiving HBOT and 3.01 QALYs for controls. Estimated cost to treat all prevalent DFU cases in Canada was CND$14.4–19.7 million/year over 4 years. If seven-person HBOT chambers were used, a further nineteen to thirty-five machines would be required nationally.

Conclusions:Adjunctive HBOT for DFU is cost-effective compared with standard care. Additional HBOT capacity would be needed if it were to be adopted as the standard of care throughout Canada.
Economic evaluation of screening for open-angle glaucoma
Authors: Hernández Rodolfo A. , Burr Jennifer M. , Vale Luke D.
Published: April 2008

Objectives:The aim of this study was to assess the cost-effectiveness of screening for open-angle glaucoma (OAG) in the United Kingdom, given that OAG is an important cause of blindness worldwide.

Methods:A Markov model was developed to estimate lifetime costs and benefits of a cohort of patients facing, alternatively, screening or current opportunistic case finding strategies. Strategies, varying in how screening would be organized (e.g., invitation for assessment by a glaucoma-trained optometrist [GO] or for simple test assessment by a technician) were developed, and allowed for the progression of OAG and treatment effects. Data inputs were obtained from systematic reviews. Deterministic and probabilistic sensitivity analyses were performed.

Results:Screening was more likely to be cost-effective as prevalence increased, for 40 year olds compared with 60 or 75 year olds, when the re-screening interval was greater (10 years), and for the technician strategy compared with the GO strategy. For each age cohort and at prevalence levels of ≤1 percent, the likelihood that either screening strategy would be more cost-effective than current practice was small. For those 40 years of age, “technician screening” compared with current practice has an incremental cost-effectiveness ratio (ICER) that society might be willing to pay when prevalence is 6 percent to 10 percent and at over 10 percent for 60 year olds. In the United Kingdom, the age specific prevalence of OAG is much lower. Screening by GO, at any age or prevalence level, was not associated with an ICER < £30,000.

Conclusions:Population screening for OAG is unlikely to be cost-effective but could be for specific subgroups at higher risk.
Extracapsular hip fracture management: Cost-consequences analysis of two alternative operative methods
Authors: Papakonstantinou Vassiliki V. , Kaitelidou Daphne , Gkolfinopoulou Kassiani D. , Siskou Olga Ch. , Papapolychroniou Theodoros , Baltopoulos Panagiotis , Liaropoulos Lycourgos
Published: April 2008

Objectives:The aim of this prospective study was to perform a cost and outcome comparison between two alternative operative techniques (osteosynthesis and hemiarthroplasty) used in the treatment of elderly patients with unstable trochanteric hip fracture.

Materials and Methods:One hundred seventy-three trochanteric hip fracture patients were followed-up for 1 year after surgery. For each operative technique, hospital treatment's cost per patient was computed. Mortality and complication rate in-hospital and at specific time points after surgery were used as outcome measures. Patients' functional level before and after hip fracture was estimated according to their mobility and ability to perform basic and instrumental activities of daily living.

Results:The cost for patients undergoing osteosynthesis reached €1,931 per case, whereas for those treated with hemiarthroplasty reached €3,719 per case (2001 rates). There was no statistically significant difference regarding in-hospital mortality and complication rate, as well as mortality and complication rate 1 year after surgery, between the two patient groups.

Conclusions:The quite similar performance of the two operative techniques suggests that cost could be the key factor for choosing between them. However, it is critical that many more randomized studies, with larger sample sizes and wider follow-up time periods should be conducted.
Analysis of strengths, weaknesses, opportunities, and threats in the development of a health technology assessment program in Turkey
Authors: Kahveci Rabia , Meads Catherine
Published: April 2008

Objectives:The Turkish healthcare system is currently undergoing reform, and efficient use of resources has become a key factor in determining the allocation of resources. The objective of this study was to analyze strengths, weaknesses, opportunities, and threats (SWOT) in the development of a health technology assessment (HTA) program in Turkey.

Methods:A SWOT analysis was performed using a literature review and interviews with key people in the Turkish Ministry of Health and Ministry of Labor and Social Security.

Results:Regarding recent reforms in health care, investments for information network and databank are the strengths, but the traditional “expert-based” decision making, poor availability of data, and poor quality of data could be seen as some of the weaknesses. Another major weakness is lack of general awareness of HTA. Increasing demand for transparency in decision making, demand for evidence, and demand for credibility by decision makers are some of the opportunities, and current healthcare reforms, i.e., restructuring of healthcare and general health insurance, could also be seen as major opportunities. These opportunities unfortunately could be threatened by lack of funding, and resources are challenged by large, recent national investments.

Conclusions:There is a good opportunity for Turkey to use the skills in HTA currently being developed through activities in Europe and the Americas to assist in the development of a much more cost-effective and transparent healthcare system in Turkey.
On inverse problems in secondary oil recovery
Authors: ISAKOV VICTOR
Published: April 2008

We review simple models of oil reservoirs and suggest some ideas for theoretical and numerical study of this important inverse problem. These models are formed by a system of an elliptic and a parabolic (or first-order hyperbolic) quasilinear partial differential equations. There are and probably there will be serious theoretical and computational difficulties mainly due to the degeneracy of the system. The practical value of the problem justifies efforts to improve the methods for its solution. We formulate ‘history matching’ as a problem of identification of two coefficients of this system. We consider global and local versions of this inverse problem and propose some approaches, including the use of the inverse conductivity problem and the structure of fundamental solutions. The global approach looks for properties of the ground in the whole domain, while the local one is aimed at recovery of these properties near wells. We discuss the use of the model proposed by Muskat which is a difficult free boundary problem. The inverse Muskat problem combines features of inverse elliptic and hyperbolic problems. We analyse its linearisation about a simple solution and show uniqueness and exponential instability for the linearisation.
The extensional flow of a thin sheet of incompressible, transversely isotropic fluid
Authors: GREEN J. EDWARD F. , FRIEDMAN AVNER
Published: April 2008

Motivated by the aim of modelling the mechanical behaviour of biological gels (such as collagen gels) which have a fibrous microstructure, we consider the extensional flow of a thin two-dimensional film of incompressible, transversely isotropic viscous fluid. Neglecting inertia, and the effects of gravity and surface tension, leading-order equations are derived from a perturbation expansion of the full flow problem in powers of the (small) inverse aspect ratio. The existence and uniqueness of the solution of the reduced system of equations for small times is then proven. Special cases, in which the solution may be determined explicitly, are considered and we discuss the physical interpretation of the results.
Turing instability of anomalous reaction–anomalous diffusion systems
Authors: NEC Y. , NEPOMNYASHCHY A. A.
Published: April 2008

Linear stability theory is developed for an activator–inhibitor model where fractional derivative operators of generally different exponents act both on diffusion and reaction terms. It is shown that in the short wave limit the growth rate is a power law of the wave number with decoupled time scales for distinct anomaly exponents of the different species. With equal anomaly exponents an exact formula for the anomalous critical value of reactants diffusion coefficients' ratio is obtained.
Enhanced Secretion of Heterologous Proteins from Yeast by Overexpression of Ribosomal Subunit RPP0
Authors: Wentz Alane E. , Shusta Eric V.
Published: April 2008

Previously, we have shown that single‐gene overexpression of five yeast genes ( CCW12, CWP2, ERO1, RPP0, and SED1) promoted increased secretion levels of several single‐chain antibody fragments and single‐chain T‐cell receptors from Saccharomyces cerevisiae (Wentz, A. E.; Shusta, E. V. Appl. Environ. Microbiol. 2007, 73, (4), 1189–1198). In this study, several proteins possessing different protein folds were secreted from yeast overexpressing each of the five genes to determine the generality of the secretion enhancers. Only one gene encoding a ribosomal subunit ( RPP0) enhanced secretion levels for multiple proteins: a single‐chain antibody (the 4–4–20 anti‐fluorescein scFv) and green fluorescent protein (GFP). Protein induction time‐course experiments revealed increased secretion with RPP0 overexpression for 4–4–20 as early as 40 h post‐induction. Effects on GFP secretion levels were not evident until late induction times where overexpression of RPP0 limited post‐secretion protein loss, but absolute yields did not exceed those observed at earlier induction times. The effects of RPP0 overexpression on secreted protein yields did not appear to directly involve ribosome function, but instead RPP0 overexpression indirectly regulated acidification of the yeast medium by preventing upregulation of the yeast plasma membrane H+‐ATPase gene, PMA1. Combining RPP0 overexpression with nutrient supplementation stimulated additional protein secretion for the 4–4–20 scFv with higher per cell secretion that corresponded to 6‐fold increases in volumetric yield.
Enhancement of Mussel Adhesive Protein Production in Escherichia coli by Co‐expression of Bacterial Hemoglobin
Authors: Kim Doil , Hwang Dong Soo , Kang Dong Gyun , Kim Jaoon Y. H. , Cha Hyung Joon
Published: April 2008

Mussel adhesive proteins (MAPs) have been considered as potential underwater and medical bioadhesives. Previously, we reported a functional expression of recombinant MAP hybrid fp‐151, which is a fusion protein with six type 1 (fp‐1) decapeptide repeats at each type 5 (fp‐5) terminus, with practical properties in Escherichia coli. In the present work, we introduced the Vitreoscilla hemoglobin (VHb) co‐expression strategy to enhance the production levels of hybrid fp‐151 since VHb has been successfully used for efficient oxygen utilization in several expression systems, including E. coli. In both batch‐type flask and fed‐batch‐type bioreactor cultures, we found that co‐expression of VHb conferred higher cell growth and hybrid fp‐151 production. Its positive effects were significantly increased in high cell density bioreactor cultures as the microaerobic environment was more quickly and severely formed. We obtained a ∼1.9‐fold higher (∼1 g/L) production of MAP fp‐151 from VHb co‐expressing cells in fed‐batch bioreactor cultures as compared to that from VHb non‐expressing cells. Collectively and regardless of the culture type, VHb co‐expression strategy was successful in enhancing the production of recombinant mussel adhesive proteins in the E. coli expression system.
Geophysical mapping of ground ice using a combination of capacitive coupled resistivity and ground‐penetrating radar, Northwest Territories, Canada
Authors: De Pascale Gregory P. , Pollard Wayne H. , Williams Kevin K.
Published: April 2008

The nature and distribution of ground ice are two of the most unpredictable geological variables in near‐surface deposits characterized by continuous permafrost. Subsurface information about ground ice distribution and structure can be obtained either by invasive and environmentally destructive techniques like drilling and excavation or by noninvasive low‐impact geophysical methods. In this study, coordinated measurements by two complementary geophysical tools, capacitive‐coupled resistivity (CCR) and ground‐penetrating radar (GPR) were used to map ground ice in a variety of locations in the Mackenzie Delta region of the western Canadian Arctic. Both CCR and GPR systems are highly portable (especially on snow covered surfaces) and very effective in collecting data under winter conditions when cold ground temperatures ensure that nearly all liquid water is frozen and signal penetration is enhanced. CCR and GPR readily detect stratigraphic differences including the contacts between massive ice deposits and enclosing sediments. GPR is widely used in permafrost research, but CCR has been used in only a few studies. This is the first study to combine results from both systems by collecting complementary data sets along coincident transects. We demonstrate that when combined, these data increase the quality and interpretation of subsurface information beyond what could be determined by either of the instruments alone. The complementary nature of these two geophysical tools facilitated the detection and mapping of massive ground ice, ice‐rich sediments, ice wedges, thermokarst, and basic stratigraphic relationships. This study breaks new ground by documenting the benefits of using these techniques together in permafrost investigations.
Spatiotemporal prediction of shallow water table depths in continental China
Authors: Yuan Xing , Xie Zhenghui , Liang Miaoling
Published: April 2008

Macro‐scale spatiotemporal distribution of shallow water table depths is important for terrestrial‐ecosystem and climate research, and management of water resources. In this paper, an approach is presented to predict the water table depths from climate forcing at a large scale for a region such as continental China. This is achieved by adopting transfer function‐noise (TFN) models and parameter regionalization methods. The parameters of the TFN models, which use precipitation surplus (precipitation minus potential evapotranspiration) as the input and water table depth as the output, are calibrated in gauged areas by the Kalman filter method coupled with the global optimization algorithm SCE‐UA (shuffled complex evolution method developed at The University of Arizona), and the calibrated parameters are then regionalized to ungauged areas for the region within the same classified zones based on Gaussian Mixture Model (GMM) clustering method. The region such as continental China is classified into several zones by the GMM clustering method according to soil and climate characteristics. Verification and cross‐validation show that the proposed methods for calibration and regionalization of the TFN‐models for estimation of the water table depths are effective. The spatial and temporal variations of water table depths at a macro‐scale in continental China are predicted by TFN models with the calibrated parameters for gauged areas and the regionalized parameters for ungauged areas.
Oscillations of global mean TEC
Authors: Hocke Klemens
Published: April 2008

The global mean of TEC (total electron content) is retrievable from signals of the global navigation satellite system (GNSS) received by the world‐wide network of GNSS ground stations. The time series of global mean TEC show dominant fluctuations with periods of 11‐year, 1‐year, 0.5‐year, and 27‐day. The annual variation of global mean TEC confirms the unsolved puzzle that “there is more ionosphere in January than in July”. Global mean TEC varies from +12.5% in January to −12.5% in July while the annual variation of solar irradiance due to the orbital eccentricity of the Earth is only ±3.3%. The oscillations of global mean TEC can be related to oscillations of the ionizing, solar EUV (extreme ultraviolet) irradiance as represented by the Mg II index. Comparing the dominant spectral components of EUV and global mean TEC, we find different amplification factors ΔTEC/ΔMg II for each spectral component. Depending on periodicity, a 1% ‐variation of solar EUV irradiance can induce variations of global mean TEC from 3.8 to 22%. While the 27‐day oscillation of EUV perfectly correlates with the 27‐day oscillation of global mean TEC (r = 0.90), we find a weak correlation (r = 0.31) between the 13.5‐day oscillations of global mean TEC and EUV. The amplitude modulations of the spectral components of global mean TEC during solar cycle‐23 are derived, and influences of atmospheric dynamics are discussed. The typical response of global mean TEC to solar flares is derived by a superposed epoch analysis of 240 major flares of solar cycle‐23 and gives new insights into the Sun‐Earth connection chain.
Recently discovered small polar motion loops and their atmospheric excitation mechanism
Authors: Johnson Thomas J.
Published: April 2008

Polar motion is the relative motion of the solid Earth with respect to its rotational axis. Recently, small loops have been discovered in unfiltered polar motion observations. These loops with periods less than 21 d and sizes ranging from a silver dollar coin to a compact disc (when projected onto the surface of the Earth) are currently observable because every ∼6.4 years the Chandler, annual, and semiannual variations that dominate this motion destructively interfere and act like a high‐pass filter. These loops, as well as diurnal polar motion variations, are shown to be significantly correlated to variations in atmospheric angular momentum that result primarily from rapid fluctuations in atmospheric pressure fields with the contributions from the winds playing a smaller variable role. Finally, the results show that variations in the speed of weather patterns and whether or not the surface winds are interacting with land or oceans have an effect on polar motion that is observable with current geodetic observational techniques.
An idealized two‐dimensional approach to study the impact of the West African monsoon on the meridional gradient of tropospheric ozone
Authors: Saunois M. , Mari C. , Thouret V. , Cammas J. P. , Peyrillé P. , Lafore J. P. , Sauvage B. , Volz‐Thomas A. , Nédélec P. , Pinty J. P.
Published: April 2008

An idealized vertical‐meridional zonally symmetrical version of the Méso‐NH model is used to study the response of tropospheric ozone to the dynamics of the West African monsoon, as well as surface emissions and NOx‐production by lightning (LNOx). An O3‐NOx‐VOC chemical scheme has been added to the dynamical model, including surface emissions and a parameterization of the LNOx production. The model shows that the ozone precursors emitted at the surface are uplifted by deep convection and then advected in the upper branches of the Hadley cells on both sides of the Inter Tropical Convergence Zone (ITCZ). The NOx produced by lightning promotes chemical ozone production in the middle and upper troposphere from the oxidation of CO and VOCs. The analysis of the convective and chemical tendencies shows that the ozone minimum at the ITCZ is induced by venting of ozone‐poor air masses into the upper troposphere. The bi‐dimensional model suffers from limitations due to the absence of exchange with the higher latitudes and ventilation in the zonal direction. Despite of these restrictions, sensitivity simulations show that the LNOx source and biogenic VOCs are necessary to create the meridional gradient of ozone observed by the Measurements of OZone and water vapor by in‐service AIrbus airCraft (MOZAIC) aircrafts in the southern Hadley cell. The LNOx source is also required to maintain the meridional ozone gradient up to 24°N in the northern Hadley cell. The modeled meridional gradient of O3 in the upper troposphere ranges from 0.22 to 0.52 ppbv/deg without the LNOx source and from 0.60 to 1.08 ppbv/deg with the LNOx source, in the southern and the northern cells respectively.
Synthesis of information on aerosol optical properties
Authors: Liu Hongqing , Pinker R. T. , Chin M. , Holben B. , Remer L.
Published: April 2008

In a previous study (Liu et al., 2005) obtained are global scale estimates of aerosol optical depth at 0.55 μm based on spatial and temporal variation patterns from models and satellite observations, regulated by the Aerosol Robotic Network (AERONET) measurements. In this study an approach is developed to obtain information on global distribution of the single scattering albedo (ω0), the asymmetry parameter (g), and the normalized extinction coefficient over shortwave (SW) spectrum. Since space observations of ω0 are in early stages of development and none are available for g, first an approach was developed to infer them from relevant information from the Global Ozone Chemistry Aerosol Radiation and Transport (GOCART) model, Moderate Resolution Imaging Spectroradiometer (MODIS) and AERONET retrievals. The single scattering albedo is generated by extending GOCART ω0 at 0.55 μm to the entire SW spectrum using spectral dependence derived from AERONET retrievals. The asymmetry parameter over the solar spectrum is derived from the MODIS Ångström wavelength exponent, utilizing a relationship based on AERONET almucantar observations. The normalized extinction coefficient is estimated from the MODIS Ångström wavelength exponent. The methodology was implemented as a “proof of concept” with one year of data. The approach described here is a step in preparedness for utilizing information from new observing systems (e.g., MISR, A‐Train constellation) when available. The impact of the newly derived information on the quality of satellite based estimates of surface radiative fluxes was evaluated and is presented by Liu and Pinker (2008).
NASA/Aura/Microwave Limb Sounder water vapor validation at Mauna Loa Observatory by Raman lidar
Authors: Barnes John E. , Kaplan Trevor , Vömel Holger , Read William G.
Published: April 2008

The NASA/Aura/Microwave Limb Sounder (MLS) instrument has been compared to the Mauna Loa Observatory Raman water vapor lidar. Calibration of the lidar used Vaisala RS80‐H radiosondes launched from the observatory. The average standard deviation between the sondes and the lidar, in the range 6 km to 11.5 km, is 11.9%. The sondes indicate no overlap correction for the lidar at low altitudes is necessary. A comparison was made between the lidar total column water and a GPS total column water measurement as a check on the calibration, resulting in a correlation slope of 1.026 ± 0.058 and R2 = 0.84. The MLS measurements are significantly better in the stratosphere where the lidar has poor sensitivity. The MLS measurement in the troposphere has much lower altitude resolution than the lidar so the validation overlap altitudes are limited. A comparison is made with version 1.5 MLS data for 32 overpasses at the three MLS altitudes in the troposphere. The GPS total column water measurement was used to screen the overpasses by eliminating ones where the water varied by more than 50% during the lidar integration period. At 147 hPa the MLS data show a dry bias of 44.8% ± 36%. At 215 hPa the MLS measurement also shows a dry bias of 22.3% ± 22%, and at 316 hPa there is a dry bias of 19.9% ± 46%. The dry bias seen is consistent with the cryogenic frost point hygrometer (CFH) measurements at many latitudes (23% ± 37% at 215 hPa and 4% ± 62% at 316 hPa).
Wind field differences between three meteorological reanalysis data sets detected by evaluating atmospheric excitation of Earth rotation
Authors: Masaki Y.
Published: April 2008

We compared atmospheric excitations of the varying Earth rotation calculated from three different meteorological reanalysis data sets (NCEP/NCAR, NCEP‐DOE and ERA‐40) over 23 years, from 1979 to 2001. Atmospheric excitations are evaluated by atmospheric angular momentum (AAM) functions. We found that differences in AAM functions are primarily caused by differences in the wind data, especially the northward wind data, between the three reanalysis data sets. Differences between the NCEP‐DOE and ERA‐40 AAM functions are larger than those between the NCEP/NCAR and NCEP‐DOE ones. The northward wind differences that have a large effect on the equatorial AAM functions originate from the upper troposphere at the tropics and midlatitudes in the southern hemisphere, especially in three regions: east Pacific off Latin America, Africa and the Indian Ocean. The eastward wind differences are seen at midlatitudes in the southern hemisphere. These differences are not confined to a single frequency. The difference spectra show a reddish frequency dependence with some peaks in seasonal bands and tidal diurnal bands. Since the eastward and northward winds over the tropics can most efficiently change the Earth's spin rate and polar motion, respectively, the wind accuracy over the tropics directly determines the accuracy in evaluations of the atmospheric excitations.
Antarctic ice mass balance estimates from GRACE: Tidal aliasing effects
Authors: Moore Philip , King Matt A.
Published: April 2008

Geophysical interpretation of GRACE gravity fields has provided estimates of Antarctic ice mass change. Such analyses rely on proper consideration of ocean tidal effects through the models CSR4 and FES2004. In general, mis‐modeling of tidal constituents with aliasing period less than 30 day will not have significant impact on ice mass change. However, for constituents, such as K1, K2, and S2, the aliasing period is sufficiently large to potentially compromise long‐term variability studies. Here we quantify tidal aliasing over Antarctica by simulating GRACE signatures due to differences between CSR4 and FES2004, and the best available circum‐Antarctic model, TPXO6.2. The S2 simulations are in close agreement with the observed S2 signal from GRACE. Simulations of ice mass change show that over 2002–2006 long‐term K1 and K2 aliasing is equivalent to a rate error of 4.5 ± 1.3 km3/a of ice with CSR4, but only 0.2 ± 0.2 km3/a with FES2004. After spatial averaging and destriping, K1 plus K2 mis‐modeling in CSR4 (FES2004) introduce point‐wise errors up to 5 (2) mm/a in equivalent water height over a 3.5 year period. With observed mass change equivalent to less than 30 mm/a of water height over much of Antarctica, the simulations show tidal aliasing uncertainty at the 2–3 mm/a level for August 2002–January 2006, or ∼10% of the signal. With GRACE Release 04, the revised estimate (April 2002–January 2006) of published ice volume decrease is 164 ± 80 km3/a of ice, although this value depends very much on the GIA model and GRACE analysis approach.
An empirical orthogonal function model of total electron content over China
Authors: Mao Tian , Wan Weixing , Yue Xinan , Sun Lingfeng , Zhao Biqiang , Guo Jianpeng
Published: April 2008

In this paper a climatology model of total electron content (TEC) over China has been developed on the basis of the empirical orthogonal function (EOF) analysis using Global Positioning System (GPS) data from the International Global Navigation Satellite System Service (IGS) and Crust Movement Observation Network of China (CMONOC) covering almost the whole Chinese sector during 1996–2004. The model well represents observational data with mean bias of −0.00994 TECU (1 TECU = 1.0 × 1016 el· m−2) and standard deviation of 5.42 TECU. Then the EOF model and IRI have been used in three‐dimensional variational (3DVAR) data assimilation experiments separately, and results reveal that the ability of assimilation nowcasting for the EOF model is better as it provides a more authentic background.
Runoff characteristics of the Changjiang River during 2006: Effect of extreme drought and the impounding of the Three Gorges Dam
Authors: Dai Zhijun , Du Jinzhou , Li Jiufa , Li Weihua , Chen Jiyu
Published: April 2008

In 2006, the Changjiang basin runoff reached its lowest level in the last 50 years, and the water level in the Three Gorges Dam (TGD) was raised from 135 m to 156 m. Based on routine water level and runoff measurements at 10 field stations, the water level in flood season during the last 50 years was lowest in 2006, a situation here we describe as “no flood in the flood season” (NFFS). In contrast, there was no obvious change in runoff of the mid‐lower reaches of the Changjiang river (MLRCR) in the drought season in 2006, which we correspondingly describe as “no drought in the drought season (NDDS)”. The extreme drought of Changjiang and impounding of TGD contributed to NFFS. However, the adjustment of TGD and the replenishment from tributaries and lakes resulted in NDDS. Meanwhile, 54% of the water flux was lost at Datong during September 20 to October 27, 2006, in comparison with the same period in 2005. It can be estimated that the impounding of TGD and the extreme drought in 2006 contributed 9% and 45% of this loss, respectively.
Arctic Ground Squirrel (Spermophilus Parryii) Hippocampal Neurons Tolerate Prolonged Oxygen—Glucose Deprivation and Maintain Baseline ERK1/2 and JNK Activation Despite Drastic ATP Loss
Authors: Christian Sherri L , Ross Austin P , Zhao Huiwen W , Kristenson Heidi J , Zhan Xinhua , Rasley Brian T , Bickler Philip E , Drew Kelly L
Published: April 2008

Oxygen—glucose deprivation (OGD) initiates a cascade of intracellular responses that culminates in cell death in sensitive species. Neurons from Arctic ground squirrels (AGS), a hibernating species, tolerate OGD in vitro and global ischemia in vivo independent of temperature or torpor. Regulation of energy stores and activation of mitogen-activated protein kinase (MAPK) signaling pathways can regulate neuronal survival. We used acute hippocampal slices to investigate the role of ATP stores and extracellular signal-regulated kinase (ERK)1/2 and Jun NH2-terminal kinase (JNK) MAPKs in promoting survival. Acute hippocampal slices from AGS tolerated 30 mins of OGD and showed a small but significant increase in cell death with 2 h OGD at 37 C. This tolerance is independent of hibernation state or season. Neurons from AGS survive OGD despite rapid ATP depletion by 3 mins in interbout euthermic AGS and 10 mins in hibernating AGS. Oxygen—glucose deprivation does not induce JNK activation in AGS and baseline ERK1/2 and JNK activation is maintained even after drastic depletion of ATP. Surprisingly, inhibition of ERK1/2 or JNK during OGD had no effect on survival, whereas inhibition of JNK increased cell death during normoxia. Thus, protective mechanisms promoting tolerance to OGD by AGS are downstream from ATP loss and are independent of hibernation state or season.
Preconditioning Mediated by Sublethal Oxygen—Glucose Deprivation-Induced Cyclooxygenase-2 Expression via the Signal Transducers and Activators of Transcription 3 Phosphorylation
Authors: Kim Eun J , Raval Ami P , Perez-Pinzon Miguel A
Published: April 2008

The signal transducers and activators of transcription (STATs) were found to be essential for cardioprotection. However, their role in preconditioning (PC) neuroprotection remains undefined. Previously, our studies showed that PC mediated a signaling cascade that involves activation of epsilon protein kinase C (εPKC), extracellular signal-regulated kinase (ERK1/2), and cyclooxygenase-2 (COX-2) pathways. However, the intermediate pathway by which ERK1/2 activates COX-2 was not defined. In this study, we investigated whether the PC-induced signaling pathway requires phosphorylation of STAT isoforms for COX-2 expression. To mimic PC or lethal ischemia, mixed cortical neuron/astrocyte cell cultures were subjected to 1 and/or 4 h of oxygen—glucose deprivation (OGD), respectively. The results indicated serine phosphorylation of STAT3 after PC or εPKC activation. Inhibition of either εPKC or ERK1/2 activation abolished PC-induced serine phosphorylation of STAT3. Additionally, inhibition of STAT3 prevented PC-induced COX-2 expression and neuroprotection against OGD. Therefore, our findings suggest that PC signaling cascade involves STAT3 activation after εPKC and ERK1/2 activation. Finally, we show that STAT3 activation mediates COX-2 expression and ischemic tolerance.
Worksite Study Promoting Activity and Changes in Eating (PACE): Design and Baseline Results
Authors: Beresford Shirley A. A. , Locke Emily , Bishop Sonia , West Briana , McGregor Bonnie A. , Bruemmer Barbara , Duncan Glen E. , Thompson Beti
Published: April 2008

Objective: Based on previous worksite‐wide intervention studies and an ecological framework, we created a behavioral intervention program to maintain or reduce weight through healthy eating and physical activity. The design and evaluation plan of the group‐randomized trial and the recruitment of worksites are described. Preliminary results regarding the dietary and physical activity behaviors associated with BMI are discussed.

Research Methods and Procedures: The intervention used an ecological framework modified by qualitative methods that identified salient barriers and facilitators of behavioral change. Approximately 30 transportation, manufacturing, utilities, personal, household, and miscellaneous service companies in the greater Seattle area are being recruited to the trial. The study population for the present analysis consists of 18 worksites from the first two randomization waves. Dietary behavior was assessed, not by calories, but by behavioral measures related to BMI. Physical activity behaviors were surveyed. BMI is derived from reported height and weight at baseline.

Results: The intervention has been developed with a specified minimum suite of strategies within the defined framework. Response rates to the baseline survey among the 18 worksites are 81% on average. After adjusting for age, gender, race, and education, BMI was associated with frequency of intensity‐adjusted physical activity, sweat‐inducing exercise, fast food meals, soft drinks, eating while doing another activity, and fruit and vegetable intake.

Discussion: Worksite‐wide intervention strategies can be adapted to target obesity prevention. Employees are willing to participate in surveys at high rates. Several measures of physical activity and eating choices are associated with baseline BMI.
Keeping a Step Ahead: Formative Phase of a Workplace Intervention Trial to Prevent Obesity
Authors: Zapka Jane , Lemon Stephenie C. , Estabrook Barbara B. , Jolicoeur Denise G.
Published: April 2008

Objective:Ecological interventions hold promise for promoting overweight and obesity prevention in worksites. Given the paucity of evaluative research in the hospital worksite setting, considerable formative work is required for successful implementation and evaluation. This paper describes the formative phases of Step Ahead, a site‐randomized controlled trial of a multilevel intervention that promotes physical activity and healthy eating in six hospitals in central Massachusetts. The purpose of the formative research phase was to increase the feasibility, effectiveness, and likelihood of sustainability of the intervention.

Research Methods and Procedures:The Step Ahead ecological intervention approach targets change at the organization, interpersonal work environment, and individual levels. The intervention was developed using fundamental steps of intervention mapping and important tenets of participatory research. Formative research methods were used to engage leadership support and assistance and to develop an intervention plan that is both theoretically and practically grounded. This report uses observational data, program minutes and reports, and process tracking data.

Results:Leadership involvement (key informant interviews and advisory boards), employee focus groups and advisory boards, and quantitative environmental assessments cultivated participation and support. Determining multiple foci of change and designing measurable objectives and generic assessment tools to document progress are complex challenges encountered in planning phases.

Discussion:Multilevel trials in diverse organizations require flexibility and balance of theory application and practice‐based perspectives to affect impact and outcome objectives. Formative research is an essential component.
Development of ACTION! Wellness Program for Elementary School Personnel
Authors: Webber Larry S. , Johnson Carolyn C. , Rose Donald , Rice Janet C.
Published: April 2008

Objective: The prevalence of overweight and obesity has increased dramatically in the adult population over the past 2 decades. Almost two‐thirds of the adult population works outside the home; thus, interventions implemented at the worksite are viable for obesity reduction. Elementary schools are worksites that have a number of resources that can encourage a healthy lifestyle. The purpose of this paper is to describe the formative research activities and how these were used to design the ACTION! Wellness Program for Elementary School Personnel.

Research Methods and Procedures: Formative data were collected using focus groups, a school survey, and an environmental audit. Focus groups were conducted in three elementary schools, whereas the school survey and environmental audit were collected in 24 elementary schools. The intervention was then tested as a pilot study in one school to determine feasibility and receptivity and refine its components.

Results: Participants in the focus groups indicated that most had experience with trying to lose weight, some had positive social support, and most had little free time at school; however, most were very receptive to having a weight control intervention program at their school. Eighteen (75%) of the schools had snack vending machines on the school site, and all had cold drink machines. All 24 schools had at least one indoor site that could be used for physical activity programs. All schools were in neighborhoods conducive for walking.

Discussion: ACTION! will take advantage of the school resources in implementing an environmental intervention to reduce overweight and obesity. This paper describes the progression of events that led to the final trial.
“Pizza Is Cheaper Than Salad”: Assessing Workers' Views for an Environmental Food Intervention
Authors: Devine Carol M. , Nelson Janet A. , Chin Nancy , Dozier Ann , Fernandez Isabel Diana
Published: April 2008

Objective: “Images of a Healthy Worksite” aims to provide easy access to healthful foods and to reduce sedentarism at the worksite—to prevent weight gain. Formative research for the nutrition intervention component was aimed at gaining a broad understanding of the sociocultural role of food and eating among workers and worker perspectives on socially feasible and culturally acceptable environmental intervention strategies.

Research Methods and Procedures: Using an adapted PRECEDE health planning model, we conducted ecological, educational, environmental, and administrative assessments at the worksite. Through 15 in‐depth interviews, five focus groups, and community mapping at two sites with 79 administrators, managers, workers, and food service personnel (51% men, 82% white), we assessed workers' perspectives on physical, sociocultural, economic, and policy environments. Data were coded for predisposing, enabling, and reinforcing factors related to intervention strategies in vending, cafeteria, catering, and informal food environments. After classification for reach, intensity, and sustainability, objectives and evaluation plans were developed for each highly ranked strategy.

Results: Key sociocultural factors affecting food and eating included: stress‐related eating in a downsizing workplace, enthusiasm for employer‐sponsored weight gain prevention efforts that respect personal privacy, and the consequences of organizational culture on worker access to the food and eating environment. Workers supported healthier cafeteria and catering options, bringing healthful foods closer, and labeling of healthful options.

Discussion: We provide a practical and systematic approach to formative research and assess the interrelatedness of the physical, policy, economic, and sociocultural factors that affect environmental worksite interventions to prevent weight gain among employees.