bluuebunny/crossref_metadata_2025_split huggingface dataset:
Medium term fluctuations of rainfall in southeastern England
Authors: Gray Barbara M. 
Published: February 2007

AbstractAn areal average data series based on 18 stations scattered throughout south and east England was set up. The incomplete gamma function was used as a model for the frequency distribution of the data, since it gave good agreement with the parameters of the longest record in the area, Kew (1697–1971). The power spectrum of the areal average series shows that non‐linear processes on a time scale of months or years may be involved in rainfall fluctuations. Decade average values of the total monthly rainfall of the area series were used to forecast decade mean monthly rainfall totals for 1970–1979, 1980–1989 and 1990–1999, using a mixed time series model.
An additional model test of positive feedback from high desert albedo
Authors: Ellsaesser H. W. , Maccracken M. C. , Potter G. L. , Luther F. M. 
Published: February 2007

AbstractCharney's (1975) suggestion that high desert albedo initiates a biogeophysical positive feedback response by the atmosphere has been tested in the 2‐D zonal atmospheric model, ZAM2. The results agree with the earlier test in the NASA GISS 3‐D GCM model (Charney et al. 1975) in confirming a positive feedback through precipitation but indicate a negative feedback in terms of temperature. The latter suggests that tropical deserts may play a role in air conditioning or placing an upper‐bound on the temperature of our planet.
Heat and moisture flux in the stratified boundary layer
Authors: Warhaft Z. 
Published: February 2007

AbstractUsing simple models for the form of the pressure strain terms in the heat and moisture flux transport equations, it is shown that the magnitude of the heat and moisture flux depends on the cross‐correlation coefficient of the temperature and humidity fluctuations. When the temperature and humidity fluctuations are weakly correlated it is shown that the coefficient of eddy conductivity may be significantly different from the coefficient of moisture eddy diffusivity.
The relation of the poleward flux of sensible heat during the winter half year to some zonal and meridional indices of the circulation
Authors: Miles M. K. 
Published: February 2007

AbstractSimple indices of the zonal and meridional surface circulation have been obtained for the months of the winter half year. The strength of the zonal circulation appears to be little related to the poleward flux of heat in this period. An index of the meridional circulation, measuring the strength of the main northerly and southerly currents, is much more closely related to the seasonal variation of heat flux and better represents the few year‐to‐year differences available. This result may be helpful in interpreting the secular changes in the zonal circulation.
Seasonal variation of planetary waves in the stratosphere observed by the Nimbus 5 SCR
Authors: Hirota I. 
Published: February 2007

AbstractThe structure and behaviour of planetary‐scale temperature waves in the stratosphere are described by the use of observations from the Selective Chopper Radiometer on the Nimbus 5 satellite during the two years from January 1973 to December 1974.From a latitude‐height diagram of monthly root‐mean‐square wave amplitudes, it is found that the planetary wave of wavenumber one is predominant in the upper stratosphere at middle and high latitudes throughout the year for both hemispheres. Waves of higher wavenumbers are rather weak in the summer hemisphere.Power spectral analysis of monthly r.m.s. wave amplitude for 24 months shows that the 12‐month period oscillation is prominent in middle and higher latitudes, while a 6‐month periodicity is observed in tropical latitudes for wavenumber one. The phase of maximum of the 6‐month cycle is about one month after the equinoxes, suggesting that planetary wave activity in lower latitudes is closely related to the semiannual oscillation of the equatorial zonal current in the upper stratosphere.Further analyses are made of seasonal characteristics of ‘transient’ waves to find the relationship between the wave motion and the mean zonal wind velocity. The predominant period (or phase velocity) is determined by a power spectral analysis using the Doppler effect due to the east‐west motion of waves. With wavenumber one in the upper stratosphere, a 15‐ to 20‐day period standing oscillation is observed in wintertime, while a 10‐day period westward moving wave is found in the summer hemisphere. During the spring and autumn, a standing oscillation with a period of about 3 weeks can be seen together with an 8‐ to 10‐day period westward motion. Higher wavenumbers show eastward motion in winter and no significant periodicity is found in other seasons as the wave activity is weak.These characteristic features of transient waves are explained by the theory of critical line absorption for vertical wave propagation through the mean zonal wind.
The effect of spherical geometry on momentum transports in simple baroclinic flows
Authors: Hollingsworth A. , Simmons A. J. , Hoskins B. J. 
Published: February 2007

AbstractWe consider the baroclinic instability of flows on the sphere. An approximate expression is derived for the momentum fluxes associated with exponentially growing modes. It is shown that the occurrence of these momentum fluxes depends on the Rossby beta‐effect in conjunction with the variation with latitude of the Coriolis parameter in the thermal wind relation and in the vortex stretching term. A physical interpretation of the results is presented.
The effect of soil moisture on circulation and rainfall in a tropical model
Authors: Walker Julia , Rowntree P. R. 
Published: February 2007

AbstractThe sensitivity of a tropical model to soil moisture content has been investigated using a simplified version of the UK Meteorological Office 11‐layer model. the model area represented a zonally‐symmetric version of West Africa. the results of one experiment (D) with a desert in the same latitudes as the Sahara were compared with those of another experiment (W) in which the desert was replaced by moist land. the initial fields contained an idealized easterly wave which developed during the experiments to form depressions whose movement, structure and associated rainfall were strongly influenced by the dryness of the underlying surface. the energetics of these disturbances were analysed and two distinct mechanisms for maintaining their eddy kinetic energy are proposed, depending on the soil moisture.Results from W suggest that once the land was moist it maintained itself in this state for at least several weeks. In D, however, the initial aridity north of 14°N was sustained, suggesting that ground dryness alone can cause deserts to persist. an analysis of observed rainfall data for the northern Sahel provides much stronger evidence for the persistence of rainfall anomalies from year to year than do similar analyses for the southern Sahel. the possibility that soil moisture anomalies could contribute to this persistence is briefly discussed.
The surface flow in a statistical climate model ‐ a test of a parameterization of large‐scale momentum fluxes
Authors: White A. A. 
Published: February 2007

AbstractGreen's parameterization of the latitudinal flux of zonal momentum by large‐scale eddies is investigated. In a steady‐state, β‐plane model of the zonal mean troposphere a simple basis for estimating transfer coefficients (eddy diffusivities) leads to a satisfactory representation of this large‐scale momentum flux, as indicated by the surface zonal flow. the simple basis appears inappropriate for systems in which the β‐effect is not dominant. In a spherical polar, quasi‐geostrophic model of the zonal mean troposphere an adaptation of the method leads to less satisfactory results. It is clear that the spatial variation of the transfer coefficients is more important than in the β‐plane case; and a more precise way of estimating this variation is desirable. Barotropic/baroclinic stability analyses seem likely to provide the most reliable basis, but their use would amount to an essentially different parameterization technique: less elaborate methods may be adequate.
Some aerodynamic features of a cotton canopy
Authors: Bache D. H. , Unsworth M. H. 
Published: February 2007

AbstractAnalysis of profiles measured over irrigated cotton in the Sudan Gezira showed that the crop boundary layer remained stable throughout most of the day. The shape of wind profiles measured within the canopy suggested that momentum was absorbed mostly in the upper layers of the canopy, with the lower regions remaining isolated from the microclimate above. A similarity analysis based on dynamic scaling factors yielded a generalized wind profile from which momentum diffusivities and mixing lengths were calculated. The analysis showed that aerodynamic features of the upper layers of the canopy were characterized by the friction velocity and the height of the zero‐plane displacement.
Inertial and frictional effects on rotating and stratified flow over topography
Authors: Buzzi A. , Tibaldi S. 
Published: February 2007

AbstractThe separate effects of fluid inertia and friction at the lower boundary on the flow of a rotating, stably stratified, incompressible fluid over a three‐dimensional shallow isolated obstacle are investigated.Analytic solutions of the perturbation equations are obtained as a power series expansion in the Rossby number, and some examples are presented. Possible meteorological applications to the flow over the Alps are discussed.
An observed relation between the macroscale local eddy flux of heat and the mean horizontal temperature gradient
Authors: Tucker G. B. 
Published: February 2007

AbstractFrequent and detailed upper air observations at Laverton (38°S) for 30 days during September/October 1966 are analysed to determine the local horizontal eddy flux of heat and the mean horizontal potential temperature gradient. Components in the meridional and zonal directions are studied, but a more meaningful relation emerges when the vector eddy flux is considered in relation to the vector temperature gradient. the angle, δ, between these two vectors, and the down‐gradient and cross‐gradient exchange coefficients, K and R, are derived. A 3‐tiered structure between the surface and 30 km emerges, with down‐gradient flux (K positive) in most of the troposphere and mid‐stratosphere, and counter‐gradient flux (K negative) in the lower stratosphere. the cross‐gradient flux is in the direction of the thermal wind (R positive) at nearly all heights except in the lowest layers and between 20 and 24 km. δ exhibits a fairly steady and systematic change throughout the height range analysed (2–28 km). Computations using standard upper air observations at selected Australian stations for 1970 show a mean annual pattern which is remarkably coherent with latitude (10–55°) and height (0–22km), except in the tropical troposphere. Typical derived mid‐latitude values for 1970 are:

Only part of the vertical variation in the lowest layers can be accounted for by surface frictional influences.
ℋ︁∞andl2–l∞filtering for two‐dimensional linear parameter‐varying systems
Authors: Wu Ligang , Wang Zidong , Gao Huijun , Wang Changhong 
Published: February 2007

AbstractIn this paper, the ℋ︁∞andl2–l∞filtering problem is investigated for two‐dimensional (2‐D) discrete‐time linear parameter‐varying (LPV) systems. Based on the well‐known Fornasini–Marchesini local state‐space (FMLSS) model, the mathematical model of 2‐D systems under consideration is established by incorporating the parameter‐varying phenomenon. The purpose of the problem addressed is to design full‐order ℋ︁∞andl2–l∞filters such that the filtering error dynamics is asymptotic stable and the prescribed noise attenuation levels in ℋ︁∞andl2–l∞senses can be achieved, respectively. Sufficient conditions are derived for existence of such filters in terms of parameterized linear matrix inequalities (PLMIs), and the corresponding filter synthesis problem is then transformed into a convex optimization problem that can be efficiently solved by using standard software packages. A simulation example is exploited to demonstrate the usefulness and effectiveness of the proposed design method. Copyright © 2007 John Wiley & Sons, Ltd.
A three‐outcome design for randomized comparative phase II clinical trials
Authors: Hong Shengyan , Wang Yanping 
Published: February 2007

AbstractRandomized designs have been increasingly called for use in phase II oncology clinical trials to protect against potential patient selection bias. However, formal statistical comparison is rarely conducted due to the sample size restriction, despite its appeal. In this paper, we offer an approach to sample size reduction by extending the three‐outcome design of Sargent et al. (Control Clin. Trials 2001; 22:117–125) for single‐arm trials to randomized comparative trials. In addition to the usual two outcomes of a hypothesis testing (rejecting the null hypothesis or rejecting the alternative hypothesis), the three‐outcome comparative design allows a third outcome of rejecting neither hypotheses when the testing result is in some ‘grey area’ and leaves the decision to the clinical judgment based on the overall evaluation of trial outcomes and other relevant factors. By allowing a reasonable region of uncertainty, the three‐outcome design enables formal statistical comparison with considerably smaller sample size, compared to the standard two‐outcome comparative design. Statistical formulation of the three‐outcome comparative design is discussed for both the single‐stage and two‐stage trials. Sample sizes are tabulated for some common clinical scenarios. Copyright © 2007 John Wiley & Sons, Ltd.
She'‐e‐os: gender effects and investor reactions to the announcements of top executive appointments
Authors: Lee Peggy M. , James Erika Hayes 
Published: February 2007

AbstractThis study uses Kanter's token status theory to link announcements of top executives to shareholder reactions, highlighting possible gender effects. Using a sample of top executive announcements from 1990 to 2000, our results show that investor reactions to the announcements of female CEOs are significantly more negative than those of their male counterparts. Furthermore, women who have been promoted from within a firm are viewed more positively than women who come from outside. To supplement our analysis of investor reactions, we also analyze the text of popular press articles surrounding the announcements of male and female CEOs. These results show that articles about the appointment of a female CEO tend to emphasize gender, gender‐related and other job or organizational considerations. Copyright © 2007 John Wiley & Sons, Ltd.
Strategic schemas, strategic flexibility, and firm performance: the moderating role of industry clockspeed
Authors: Nadkarni Sucheta , Narayanan V. K. 
Published: February 2007

AbstractWe examine the moderating effect of industry clockspeed on the relationship between strategic schemas, strategic flexibility and firm performance. We employ two key properties of strategic schemas: complexity and focus. Using a sample of 225 firms from 14 industries, we show that the pattern of relationships among the theoretical constructs is different in fast‐ and slow‐clockspeed industries. The results suggest that complexity of strategic schemas promotes strategic flexibility and success in fast clockspeed industries, whereas focus of strategic schemas fosters strategic persistence, which is effective in slow‐clockspeed industries. Copyright © 2007 John Wiley & Sons, Ltd.
DNA Microarrays: Design Principles for Maximizing Ergodic, Chaotic Mixing
Authors: Hertzsch Jan‐Martin , Sturman Rob , Wiggins Stephen 
Published: February 2007

AbstractIn this article we show that models of flows in DNA microarrays generated by pulsed source–sink pairs can be studied as linked twist maps. The significance of this is that it enables us to relate the flow to mathematically precise notions of chaotic mixing that can be realized through specific design criteria. We apply these techniques to three different mixing protocols, two of which have been previously described in the literature, and we are able to isolate the features of each mixer that lead to “good” or “bad” mixing. Based on this, we propose a new design to generate a “well‐mixed” flow in a DNA microarray.
Gum Arabic as a Phytochemical Construct for the Stabilization of Gold Nanoparticles: In Vivo Pharmacokinetics and X‐ray‐Contrast‐Imaging Studies
Authors: Kattumuri Vijaya , Katti Kavita , Bhaskaran Sharanya , Boote Evan J. , Casteel Stan W. , Fent Genevieve M. , Robertson David J. , Chandrasekhar Meera , Kannan Raghuraman , Katti Kattesh V. 
Published: February 2007

AbstractGold nanoparticles (AuNPs) have exceptional stability against oxidation and therefore will play a significant role in the advancement of clinically useful diagnostic and therapeutic nanomedicines. Despite the huge potential for a new generation of AuNP‐based nanomedicinal products, nontoxic AuNP constructs and formulations that can be readily administered site‐specifically through the intravenous mode, for diagnostic imaging by computed tomography (CT) or for therapy via various modalities, are still rare. Herein, we report results encompassing: 1) the synthesis and stabilization of AuNPs within the nontoxic phytochemical gum‐arabic matrix (GA–AuNPs); 2) detailed in vitro analysis and in vivo pharmacokinetics studies of GA–AuNPs in pigs to gain insight into the organ‐specific localization of this new generation of AuNP vector, and 3) X‐ray CT contrast measurements of GA–AuNP vectors for potential utility in molecular imaging. Our results demonstrate that naturally occurring GA can be used as a nontoxic phytochemical construct in the production of readily administrable biocompatible AuNPs for diagnostic and therapeutic applications in nanomedicine.
Hexanal Synthesis in Isolated Soy Proteins
Authors: Boatright W. L. , Lu G. 
Published: February 2007

AbstractSodium erythrobate (2.3 mM) and dithiothreitol (6.5 mM) caused headspace hexanal from aqueous slurries of commercial isolated soy proteins (ISP) to increase by as much as 13‐fold compared with headspace hexanal in the controls. When linoleic acid was also added, headspace hexanal levels from commercial and laboratory‐prepared ISP were further increased by as much as 18‐ and 136‐fold, respectively, compared with the levels in the controls. When13C‐labeled linoleic acid was added to aqueous mixtures of laboratory‐prepared ISP along with reducing agents, 96% of the resulting hexanal contained the13C isotope. Commercial ISP samples had about 40% of the isotopically labeled carbon incorporated into hexanal. These large increases in hexanal were almost completely prevented by heating the aqueous ISP to 100 °C or above prior to adding the reducing agent and linoleic acid. Adding cysteine or sodium sulfite reduced headspace hexanal levels from aqueous ISP slurries by more than 88%. Thiol blockers, iodoacetic acid andN‐ethylmaleimide, did not affect hexanal levels.
Remaining life estimation of used components in consumer products: Life cycle data analysis by Weibull and artificial neural networks
Authors: Mazhar M.I. , Kara S. , Kaebernick H. 
Published: February 2007

AbstractEnvironmental awareness and legislative pressures have made manufacturers responsible for the take‐back and end‐of‐life treatment of their products. To competitively exploit these products, one option is to incorporate used components in “new” or remanufactured products. However, this option is partly limited by a firm's ability to assess the reliability of used components. A comprehensive two‐step approach is proposed. The first stage phase statistically analyzes the behavior of components for reuse. A well‐known reliability assessment method, the Weibull analysis, is applied to the time‐to‐failure data to assess the mean life of components. In the second phase, the degradation and condition monitoring data are analyzed by developing an artificial neural network (ANN) model. The advantages of this approach over traditional approaches employing multiple regression analysis are highlighted with empirical data from a consumer product. Finally, the Weibull analysis and the ANN model are then integrated to assess the remaining useful life of components for reuse. This is a critical advance in sustainable management of supply chains since it allows for a better understanding of not only service requirements of product, but the remaining life in a product and hence its suitability for reuse or remanufacture. Future work should assess: (1) reduction in downtime of process equipment through the implementation of this technique as a means to better manage preventative maintenance; (2) reduce field failure of remanufactured product; (3) selling‐service strategy through implementation of the proposed methodology.
The impact of a community-based food skills intervention on cooking confidence, food preparation methods and dietary choices – an exploratory trial
Authors: Wrieden Wendy L , Anderson Annie S , Longbottom Pat J , Valentine Karen , Stead Martine , Caraher Martin , Lang Tim , Gray Bill , Dowler Elizabeth 
Published: February 2007

AbstractObjectiveTo evaluate the feasibility of undertaking a food skills intervention study in areas of social deprivation aimed at altering cooking confidence, food preparation methods and dietary choices.DesignA standardised skills programme was implemented in community-based settings. Pre- (T1) and post-intervention (T2) and 6-month follow-up (T3) measures (7-day diaries and self-administered questionnaires) were undertaken in intervention and comparison groups.SettingEight urban communities in Scotland.SubjectsOne hundred and thirteen adults living in areas of social deprivation.ResultsIt was clear that many subjects led fragmented lives and found commitment to intervention classes problematic. Sixty-three subjects completed the final (T3) assessments. The response to each component varied due to inability to attend sessions, illness, study requirements, employment, moving out of the area, change in circumstances, loss of interest and loss of postal questionnaires. At baseline, reported consumption of fruit and vegetables was low (mean frequency 8.1 ± 4.78 times per week). Fruit intake increased significantly (P < 0.05) between T1 and T2 in the intervention group (1.7 ± 2.36 to 2.7 ± 3.28 times per week) only. Between T1 and T3, there was a significant increase (P < 0.05) in intervention subjects who reported confidence in following a recipe (67–90%,).ConclusionsThis exploratory trial shows that a food skills intervention is likely to have a small but positive effect on food choice and confidence in food preparation. A full-scale randomised controlled trial in this hard-to-reach group would require a range of flexible approaches rather than a fully defined intervention, and presents challenges for trial design.
Food insecurity and subsequent weight gain in women
Authors: Jones Sonya J , Frongillo Edward A 
Published: February 2007

AbstractObjectiveCross-sectional data indicate that a relationship between household food insecurity and overweight exists among women in the USA. Cross-sectional data cannot determine if food insecurity leads to overweight as some have hypothesised. The purpose of the present study was to examine the relationship of food insecurity with subsequent weight gain in women using data from the Panel Study of Income Dynamics (PSID).Design, setting and subjectsPanel data from the 1999 and 2001 PSID, a nationally representative sample of households, were analysed using multivariate regression procedures.ResultsAverage weight gain among all women (n = 5595) was 1.1 kg on average over the two years. There were no significant differences in the percentages of women who gained a clinically significant amount (2.3 kg) by food insecurity status. Overweight women who were on a weight-gain trajectory during the 2-year period gained less if they were food-insecure. This relationship was not observed among healthy-weight or obese women.ConclusionsOverall, food insecurity does not appear to be strongly associated with subsequent weight gain in women.