bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sensitivity of moist convection to environmental humidity
Authors: Derbyshire S. H. , Beau I. , Bechtold P. , Grandpeix J.‐Y. , Piriou J.‐M. , Redelsperger J.‐L. , Soares P. M. M. 
Published: February 2005

AbstractAs part of the EUROCS (EUROpean Cloud Systems study) project, cloud‐resolving model (CRM) simulations and parallel single‐column model (SCM) tests of the sensitivity of moist atmospheric convection to midtropospheric humidity are presented. This sensitivity is broadly supported by observations and some previous model studies, but is still poorly quantified. Mixing between clouds and environment is a key mechanism, central to many of the fundamental differences between convection schemes.Here, we define an idealized quasi‐steady ‘testbed’, in which the large‐scale environment is assumed to adjust the local mean profiles on a timescale of one hour. We then test sensitivity to the target profiles at heights above 2 km.Two independent CRMs agree reasonably well in their response to the different background profiles and both show strong deep precipitating convection in the more moist cases, but only shallow convection in the driest case. The CRM results also appear to be numerically robust. All the SCMs, most of which are one‐dimensional versions of global climate models (GCMs), show sensitivity to humidity but differ in various ways from the CRMs. Some of the SCMs are improved in the light of these comparisons, with GCM improvements documented elsewhere. © Crown copyright, 2004.
The role of stability and moisture in the diurnal cycle of convection over land
Authors: Chaboureau J.‐P. , Guichard F. , Redelsperger J.‐L. , Lafore J.‐P. 
Published: February 2005

AbstractThe diurnal cycle of convection over land is investigated by a cloud‐resolving model simulation. Three regimes of convection—dry, shallow, and deep—successively take place during daytime under the presence of substantial convective available potential energy. The convective inhibition (CIN) and the normalized saturation deficit (NSD) in the cloud‐base layer are identified as the major two variables that characterize the cycle of the convective regimes. The surface heating during daytime leads to the development of a quasi‐dry well‐mixed convective planetary boundary layer (PBL). This yields a decrease of CIN while NSD remains steady. Shallow convection is initiated as soon as the CIN becomes lower locally than the vertical kinetic energy in the PBL. This timing also marks the minimum of CIN, both in local and in domain‐mean senses. Then, detrainment of moisture from the cloud layer gradually moistens the low free troposphere, resulting in a NSD decrease. Finally, deep convection is triggered when sufficient moistening is realized, as measured by a NSD minimum. During deep convection, NSD rapidly increases and CIN increases. Once CIN has exceeded the vertical kinetic energy in the PBL, deep convection ceases. Copyright © 2004 Royal Meteorological Society
On the role of drizzle in stratocumulus and its implications for large‐eddy simulation
Authors: Lenderink G. , Siebesma A. P. 
Published: February 2005

AbstractLarge‐eddy simulation (LES) of marine stratocumulus cloud‐topped boundary layers show a surprisingly large sensitivity to the prescribed forcing—this being at odds with the widespread and persistent occurrence of this cloud type. However, most LES studies have not taken drizzle explicitly into account. This note explores the damping effect (i.e. reducing the sensitivity to the forcing) that drizzle might have on the stratocumulus cloud‐topped boundary layer. A single‐column model is used to illustrate the difference in response in one model version with drizzle taken into account and one in which drizzle is inactivated. Results are shown for a simulation of the diurnal cycle of stratocumulus clouds over sea; they support the notion that the impact of drizzle is underrated in the present‐day modelling of stratocumulus‐topped boundary layers. Copyright © 2004 Royal Meteorological Society
Modelling the diurnal cycle of deep precipitating convection over land with cloud‐resolving models and single‐column models
Authors: Guichard F. , Petch J. C. , Redelsperger J.‐L. , Bechtold P. , Chaboureau J.‐P. , Cheinet S. , Grabowski W. , Grenier H. , Jones C. G. , Köhler M. , Piriou J.‐M. , Tailleux R. , Tomasini M. 
Published: February 2005

AbstractAn idealized case‐study has been designed to investigate the modelling of the diurnal cycle of deep precipitating convection over land. A simulation of this case was performed by seven single‐column models (SCMs) and three cloud‐resolving models (CRMs). Within this framework, a quick onset of convective rainfall is found in most SCMs, consistent with the results from general‐circulation models. In contrast, CRMs do not predict rainfall before noon. A joint analysis of the results provided by both types of model indicates that convection occurs too early in most SCMs, due to crude triggering criteria and quick onsets of convective precipitation. In the CRMs, the first clouds appear before noon, but surface rainfall is delayed by a few hours to several hours. This intermediate stage, missing in all SCMs except for one, is characterized by a gradual moistening of the free troposphere and an increase of cloud‐top height. Later on, convective downdraughts efficiently cool and dry the boundary layer (BL) in the CRMs. This feature is also absent in most SCMs, which tend to adjust towards more unstable states, with moister (and often more cloudy) low levels and a drier free atmosphere. This common behaviour of most SCMs with respect to deep moist convective processes occurs even though each SCM simulates a different diurnal cycle of the BL and atmospheric stability. The scatter among the SCMs results from the wide variety of representations of BL turbulence and moist convection in these models. Greater consistency is found among the CRMs, despite some differences in their representation of the daytime BL growth, which are linked to their parametrizations of BL turbulence and/or resolution. © Royal Meteorological Society, 2004. J. C. Petch's contribution is Crown copyright
An eddy‐diffusivity/mass‐flux parametrization for dry and shallow cumulus convection
Authors: Soares P. M. M. , Miranda P. M. A. , Siebesma A. P. , Teixeira J. 
Published: February 2005

AbstractRecently, a new consistent way of parametrizing simultaneously local and non‐local turbulent transport for the convective atmospheric boundary layer has been proposed and tested for the clear boundary layer. This approach assumes that in the convective boundary layer the subgrid‐scale fluxes result from two different mixing scales: small eddies, that are parametrized by an eddy‐diffusivity approach, and thermals, which are represented by a mass‐flux contribution. Since the interaction between the cloud layer and the underlying sub‐cloud layer predominantly takes place through strong updraughts, this approach offers an interesting avenue of establishing a unified description of the turbulent transport in the cumulus‐topped boundary layer. This paper explores the possibility of such a new approach for the cumulus‐topped boundary layer. In the sub‐cloud and cloud layers, the mass‐flux term represents the effect of strong updraughts. These are modelled by a simple entraining parcel, which determines the mean properties of the strong updraughts, the boundary‐layer height, the lifting condensation level and cloud top. The residual smaller‐scale turbulent transport is parametrized with an eddy‐diffusivity approach that uses a turbulent kinetic energy closure. The new scheme is implemented and tested in the research model MesoNH. Copyright © 2004 Royal Meteorological Society
Own-Brand and Cross-Brand Retail Pass-Through
Authors: Besanko David , Dubé Jean-Pierre , Gupta Sachin 
Published: February 2005

In this paper we describe the pass-through behavior of a major U.S. supermarket chain for 78 products across 11 categories. Our data set includes retail prices and wholesale prices for stores in 15 retail price zones for a one-year period. For the empirical model, we use a reduced-form approach that focuses directly on equilibrium prices as a function of exogenous supply- and demand-shifting variables. The reduced-form approach enables us to identify the theoretical pass-through rate without specific assumptions about the form of consumer demand or the conduct of a category-pricing manager. Thus, our measurements of pass-through are not constrained by specific structure on the underlying economic model. The empirical pricing model includes costs of all competing products in the category on the right-hand side (not only the cost of the focal brand) and yields estimates of both own-brand and cross-brand pass-through rates. Our results provide a rich picture of the retailer's pass-through behavior. We find that pass-through varies substantially across products and across categories. Own-brand pass-through rates are, on average, more than 60% for 9 of 11 categories, a finding that is at odds with the claims of manufacturers about retailers in general. Importantly, we find substantial evidence of cross-brand pass-through effects, indicating that retail prices of competing products are adjusted in response to a change in the wholesale price of any given product in the category. We find that cross-brand pass-through rates are both positive and negative. We explore determinants of own-brand and cross-brand pass-through rates and find strong evidence in multiple categories of asymmetric retailer response to trade promotions on large versus small brands. For example, brands with larger market shares, and brands that contribute more to retailer profits in the category, receive higher pass-through. We also find that trade promotions on large brands are less likely than small brands to generate positive cross-brand pass-through, i.e., induce the retailer to reduce the retail price of competing smaller products. On the other hand, small share brands are disadvantaged along three dimensions. Trade promotions on small brands receive low own-brand pass-through and generate positive cross-brand pass-through for larger competing brands. Moreover, small share brands do not receive positive cross pass-through from trade promotions on these larger competitors. We also find that store brands are similarly disadvantaged with respect to national brands.
A General Theory of Pass-Through in Channels with Category Management and Retail Competition
Authors: Moorthy Sridhar 
Published: February 2005

I provide a general formulation of the channel pass-through problem as a comparative static of the retail price equilibrium, and I analyze the impact of category management and retail competition on pass-through, focusing on brand and retailer differences, and the nature of the cost change being passed through—whether it is brand specific, retailer specific, both, or neither. With category management, a retailer's response to a brand-specific cost change is not limited to that brand; in general, a retailer will also change the prices of other brands. The cross-brand effect can be positive or negative, and, depending on its sign, it either enhances or attenuates pass-through. I explain the cross-brand effect as an interaction between two forces: a demand-substitution force that pushes for a negative cross-brand effect, and a strategic-complementarity force that pushes for a positive cross-brand effect. Retail competition adds another layer of strategic complementarity, causing other retailers to respond even for retailer-specific cost changes and increasing pass-through of categorywide cost changes. But its effect for brand-specific cost changes is ambiguous. I apply the theory to two commonly used demand functions—linear demand and nested logit—and show that they have significantly different pass-through properties. The paper concludes with a discussion of how the theory relates to the empirical literature, including the companion piece by Besanko et al. (Besanko, D., J-P. Dubé, S. Gupta. 2005. Own-brand and cross-brand retail pass-through. Marketing Sci. 24(1) 123–137.)
Differences in Dynamic Brand Competition Across Markets: An Empirical Analysis
Authors: Dubé Jean-Pierre , Manchanda Puneet 
Published: February 2005

We investigate differences in the dynamics of marketing decisions across geographic markets empirically. We begin with a linear-quadratic game involving forward-looking firms competing on prices and advertising. Based on the corresponding Markov perfect equilibrium, we propose estimable econometric equations for demand and marketing policy. Our model allows us to measure empirically the strategic response of competitors along with economic measures such as firm profitability. We use a rich dataset that combines sales, marketing mix, factor cost, and advertising cost data for eighteen geographic markets in the frozen entrée category. We find that larger markets tend to be less price-sensitive and more profitable than smaller markets. We also find evidence of positive carryover of own advertising on own demand. In terms of consumer substitution patterns, we find that the role of advertising (in our data) seems to be more category-building (complementary) than share-stealing (competitive). The complementary role is stronger in larger markets. On the supply side, we find that firms make smaller adjustments to own advertising as goodwill goes up. Consistent with cross-advertising effects on demand, firms make smaller (larger) adjustments to advertising in response to competitive goodwill in the less competitive larger (in the more competitive smaller) markets. Finally, we find that consumer welfare decreases (increases) in larger (smaller) markets when firms move to a zero-advertising regime.
Single-stage open reduction through a medial approach and innominate osteotomy in developmental dysplasia of the hip
Authors: Baki C. , Sener M. , Aydin H. , Yildiz M. , Saruhan S. 
Published: February 2005

We treated 15 hips (15 patients) with developmental dysplasia by a single-stage combination of open reduction through a medial approach and innominate osteotomy. The mean age of the patients at the time of operation was 20 months (13 to 30). The mean follow-up period was 9.6 years (4 to 14). At the final follow-up, 14 hips were assessed clinically as excellent and one hip as good. Radiologically, ten hips were rated as class I, four as class II and one as class III according to the criteria of Severin. No avascular necrosis was seen. No patient required subsequent surgery. Our results indicate that satisfactory results can be obtained with the single-stage combination of open reduction by the medial approach and innominate osteotomy for developmental dysplasia of the hip in a selected group of children older than 12 months. To our knowledge, no similar combined technique has been previously reported.
Rotationplasty type BI versus type BIIIa in children under the age of ten years
Authors: Hardes J. , Gosheger G. , Vachtsevanos L. , Hoffmann C. , Ahrens H. , Winkelmann W. 
Published: February 2005

Type BI rotationplasty is currently indicated for children with tumours of the proximal femur whereas type BIIIa rotationplasty is reserved for those in which the entire femur has to be removed. Our aim was to compare these two types of rotationplasty and determine whether the knee should be preserved in children with tumours of the proximal femur. We compared the post-operative complications, oncological outcome, range of movement, Enneking score and radiographs of six children, who had undergone type BI rotationplasty with those of 12 who had undergone type BIIIa rotationplasty. Patients with type BI rotationplasty had a mean Enneking score of 21.6 compared with 24.4 in those with type BIIIa rotationplasty, and worse mean results in all of the parameters investigated. We conclude that type BI rotationplasty has a worse functional outcome and more complications than type BIIIa rotationplasty in children under the age of ten years.
Surgical treatment of late developmental displacement of the hip
Authors: Angliss R. , Fujii G. , Pickvance E. , Wainwright A. M. , Benson M. K. D. 
Published: February 2005

The outcome of displaced hips treated by Somerville and Scott’s method was assessed after more than 25 years. A total of 147 patients (191 displaced hips) was reviewed which represented an overall follow-up of 65.6%. The median age at the index operation was two years. During the first five years, 25 (13%) hips showed signs of avascular change. The late development of valgus angulation of the neck, after ten years, was seen in 69 (36%) hips. Further operations were frequently necessary. Moderate to severe osteoarthritis developed at a young age in 40% of the hips. Total hip replacement or arthrodesis was necessary in 27 (14%) hips at a mean age of 36.5 years. Risk factors identified were high dislocation, open reduction, and age at the original operation. Two groups of patients were compared according to outcome. All the radiographic indices were different between the two groups after ten years, but most were similar before. It takes a generation to establish the prognosis, although some early indicators may help to predict outcome.
Osteonecrosis in retrieved femoral heads after failed resurfacing arthroplasty of the hip
Authors: Little C. P. , Ruiz A. L. , Harding I. J. , McLardy-Smith P. , Gundle R. , Murray D. W. , Athanasou N. A. 
Published: February 2005

We present the histological findings of bone retrieved from beneath the femoral components of failed metal-on-metal hip resurfacing arthroplasties. Of a total of 377 patients who underwent resurfacing arthroplasty, 13 required revision; for fracture of the femoral neck in eight, loosening of a component in three and for other reasons in two. None of these cases had shown histological evidence of osteonecrosis in the femoral bone at the time of the initial implantation. Bone from the remnant of the femoral head showed changes of osteonecrosis in all but one case at revision. In two cases of fracture which occurred within a week of implantation, the changes were compatible with early necrosis of the edge of the fracture. In the remaining six fractures, there were changes of established osteonecrosis. In all but one of the non-fracture cases, patchy osteonecrosis was seen. We conclude that histological evidence of osteonecrosis is a common finding in failed resurfaced hips. Given that osteonecrosis is extensive in resurfaced femoral heads which fail by fracture, it is likely to play a role in the causation of these fractures.
Autologous chondrocyte implantation at the knee using a bilayer collagen membrane with bone graft
Authors: Bartlett W. , Gooding C. R. , Carrington R. W. J. , Skinner J. A. , Briggs T. W. R. , Bentley G. 
Published: February 2005

Autologous chondrocyte implantation (ACI) is a technique used for the treatment of symptomatic osteochondral defects of the knee. A variation of the original periosteum membrane technique is the matrix-induced autologous chondrocyte implantation (MACI) technique. The MACI membrane consists of a porcine type-I/III collagen bilayer seeded with chondrocytes. Osteochondral defects deeper than 8 to 10 mm usually require bone grafting either before or at the time of transplantation of cartilage. We have used a variation of Peterson’s ACI-periosteum sandwich technique using two MACI membranes with bone graft which avoids periosteal harvesting. The procedure is suture-free and requires less operating time and surgical exposure. We performed this MACI-sandwich technique on eight patients, five of whom were assessed at six months and one year post-operatively using the modified Cincinnati knee, the Stanmore functional rating and the visual analogue pain scores. All patients improved within six months with further improvement at one year. The clinical outcome was good or excellent in four after six months and one year. No significant graft-associated complications were observed. Our early results of the MACI-sandwich technique are encouraging although larger medium-term studies are required before there is widespread adoption of the technique.
Longitudinal Patterns and Predictors of Alcohol Consumption in the United States
Authors: Moore Alison A. , Gould Robert , Reuben David B. , Greendale Gail A. , Carter M. Kallin , Zhou Kefei , Karlamangla Arun 
Published: February 2005

Objectives. We examined demographic predictors of longitudinal patterns in alcohol consumption. Methods. We used mixed-effects models to describe individual alcohol consumption and change in consumption with age, as well as the associations between consumption and birth year, national alcohol consumption, and demographic factors, among 14 105 adults from the National Health and Nutrition Examination Survey I Epidemiologic Follow-Up Study. Results. Alcohol consumption declined with increasing age, and individual consumption mirrored national consumption. Higher consumption was associated with male gender, being White, being married, having a higher educational level, having a higher income, being employed, and being a smoker. Faster age-related decline in consumption was associated with earlier cohorts, being male, being married, having a lower educational level, and being a smoker. Conclusions. Compared with alcohol consumption among earlier cohorts, that among recent cohorts declined more slowly with increasing age, suggesting that negative health effects of alcohol could increase in the future.
Persistence of Effects of the Checkpoints Program on Parental Restrictions of Teen Driving Privileges
Authors: Simons-Morton Bruce G. , Hartos Jessica L. , Leaf William A. , Preusser David F. 
Published: February 2005

Objectives. We describe intervention effects on parent limits on novice teenage driving.Methods. We recruited parents and their 16-year-old children (n = 469) with learner’s permits and randomized them from August 2000 to March 2003. Intervention families received persuasive newsletters related to high-risk teenage driving and a parent–teenager driving agreement; comparison families received standard information on driver safety. We conducted interviews when the adolescents obtained a learner’s permit, upon licensure, and at 3, 6, and 12 months postlicensure.Results. Intervention parents and teenagers reported stricter limits on teen driving compared with the comparison group at 12 months, with direct effects through 3 months and indirect effects through 12 months postlicensure.Conclusions. A simple behavioral intervention was efficacious in increasing parental restriction of high-risk teen driving conditions among newly licensed drivers.
Relationship Between Drug Abuse and Intimate Partner Violence: A Longitudinal Study Among Women Receiving Methadone
Authors: El-Bassel Nabila , Gilbert Louisa , Wu Elwin , Go Hyun , Hill Jennifer 
Published: February 2005

Objectives. We examined whether frequent drug use increases the likelihood of subsequent sexual or physical intimate partner violence (IPV) and whether IPV increases the likelihood of subsequent frequent drug use. Methods. A random sample of 416 women on methadone was assessed at baseline (wave 1) and at 6 months (wave 2), and 12 months (wave 3) following the initial assessment. Propensity score matching and multiple logistic regression were employed. Results. Women who reported frequent crack use at wave 2 were more likely than non–drug using women to report IPV at wave 3 (odds ratio [OR]=4.4; 95% confidence interval [CI]=2.1, 9.1; P<.01), and frequent marijuana users at wave 2 were more likely than non–drug users to report IPV at wave 3 (OR=4.5; 95% CI=2.4, 8.4; P<.01). In addition, women who reported IPV at wave 2 were more likely than women who did not report IPV to indicate frequent heroin use at wave 3 (OR=2.7; 95% CI=1.1, 6.5; P=.04). Conclusions. Our findings suggest that the relationship between frequent drug use and IPV is bidirectional and varies by type of drug.