bluuebunny/crossref_metadata_2025_split huggingface dataset:
Asymptotic profile of solutions to a non‐linear dissipative evolution system with conservation
Authors: Wang Zhian , Sang Hong 
Published: February 2007

AbstractWe investigate the asymptotic profile to the Cauchy problem for a non‐linear dissipative evolution system with conservational form

provided that the initial data are small, where constants α, ν are positive satisfying ν2<4α(1 − α), α<1. In (J. Phys. A 2005; 38:10955–10969), the global existence and optimal decay rates of the solution to this problem have been obtained. The aim of this paper is to apply the heat kernel to examine more precise behaviour of the solution by finding out the asymptotic profile. Precisely speaking, we show that, when time t → ∞ the solution $ {\psi \rightarrow De^{-(1-\alpha-\nu^{2}/{4 \alpha})t}G(t, x) \cos ((\nu / 2{\alpha})x + {\Pi / 4} + \beta)}$ and solution ${\theta \rightarrow - D \nu e^{-(1-\alpha-\nu^{2}/{ 4\alpha}) t}G(t, x)\sin((\nu/2{\alpha})x + {\Pi / 4} + \beta)}$ in the Lp sense, where G(t, x) denotes the heat kernel and $D=2\sqrt{2(\vartheta_{+}^{2}+\vartheta_{-}^{2})}$ is determined by the initial data and the solution to a reformulated problem obtained in Section 3, β is related to ϑ+ and ϑ− which are determined by (41) in Section 4. The numerical simulation is presented in the end. The motivation of this work thanks to Nishihara (Asymptotic profile of solutions to nonlinear dissipative evolution system with ellipticity. Z. Angew Math Phys 2006; 57: 604–614). Copyright © 2007 John Wiley & Sons, Ltd.
Reliability of speed of contraction and endurance dynamometric measurements of the pelvic floor musculature in stress incontinent parous women
Authors: Morin M. , Dumoulin C. , Gravel D. , Bourbonnais D. , Lemieux M.‐C. 
Published: February 2007

AbstractAimsTo evaluate the test–retest reliability of dynamometric measurements of the pelvic floor muscles (PFM) during speed and endurance tests.MethodsNineteen parous women suffering from stress urinary incontinence (SUI) participated in the study. Two PFM evaluation sessions were conducted using the dynamometric speculum. For the speed test, the women were instructed to contract maximally and relax as quickly as possible during a 15‐s test period. The speed of contraction was quantified by the rate of force development of the first contraction and the number of contractions performed. The maximal strength value attained during the speed test was also extracted from the curves. For the endurance test, the subjects were asked to maintain a maximal contraction for 90 s. The normalized area under the force curve was utilized as the endurance parameter. The reliability of the data was evaluated using the generalizability theory. Two reliability estimates were calculated, the dependability indices (Φ) and the standard error of measurement (SEM), for one measurement session involving one trial.ResultsThe indices of dependability obtained indicate that the reliability of the speed of contraction and endurance parameters are good (Φ=0.79–0.92). The corresponding SEMs were 1.39 N/s, 1 contraction, 1.00 N, and 298%*s for the rate of force development, number of contractions, maximal strength and normalized area, respectively.ConclusionThis study indicates that the speed of contraction and endurance parameters possess good test–retest reliability. The inclusion of these parameters in the PFM assessment is therefore highly recommended for assessing changes in PFM in incontinent women. Neurourol. Urodynam. 26:397–403, 2007. © 2007 Wiley‐Liss, Inc.
Minimally‐invasive electrical stimulation of the pudendal nerve: A pre‐clinical study for neural control of the lower urinary tract
Authors: Yoo Paul B. , Grill Warren M. 
Published: February 2007

AbstractAimsElectrical stimulation of afferent pudendal nerve fibers can evoke sustained bladder contractions (SBC) in cats, yet evidence of therapeutic efficacy in human subjects is lacking. This pre‐clinical study was undertaken to test the hypothesis that robust bladder contractions can be generated with a minimally‐invasive needle electrode.Materials and MethodsIn seven adult cats, triggered electromyographic (EMG) signals from the external anal sphincter (EAS) were used to minimize the needle‐to‐nerve distance; while reflex bladder contractions were recorded as 20‐sec trains of current pulses of varying amplitude (threshold to 10 mA) and frequency (1–100 Hz) were applied to the nerve. This stimulation paradigm was repeated at successively greater needle‐to‐nerve distances (0.5 cm intervals) and also at different electrode positions along the nerve.ResultsElectrophysiological access to the pudendal nerve was consistently achieved, as indicated by the average threshold for EAS activation (0.31 ± 0.19 mA). Using different combinations of stimulus amplitude and frequency, robust SBCs were evoked in every experiment. More rostral electrode positions exhibited stimulation amplitudes and corresponding maximum bladder pressures (0.68 ± 0.36 mA and 25.3 ± 3.5 cmH2O, respectively) that were comparable to those of more invasive stimulation methods.ConclusionsThe needle electrode provides a minimally‐invasive approach that will enable the study of reflexes mediated by pudendal afferents in humans, and allow pre‐operative testing before implanting a permanent device. Neurourol. Urodynam. 26:562–569, 2007. © 2007 Wiley‐Liss, Inc.
Gene polymorphisms and susceptibility to coronary artery disease
Authors: Shah Svati H. 
Published: February 2007

AbstractAs pediatric cancer survivors age, long‐term cardiovascular complications related to chemotherapeutic toxicities, as well as development of premature coronary artery disease (CAD) from radiation and increased prevalence of CAD risk factors such as obesity, are likely to become more prevalent. Despite advances in our understanding of CAD in the general population, a large amount of the variance in development of disease is unexplained. Given the strong heritability of CAD, some of this may be attributable to genetics. Premature CAD in particular segregates in families, and twin studies have shown that the genetic contribution is greater in premature CAD. In this article, we present a brief review of the literature on the genetics of CAD. Over 30 monogenic disorders feature CAD phenotypes. Recently, however, interest has shifted to understanding the genetic variation contributing to common, complex disease, where disease risk is polygenic and characterized by environmental factors, and gene–environment interactions. CAD epitomizes such a disease, and highlights the inherent difficulties in understanding the underlying genetic architecture of such diseases. Long‐term cardiovascular complications in patients who survive pediatric cancers result in significant morbidity and mortality in this population. Clinicians need to be aware of screening and treatment strategies for primary and secondary prevention of cardiovascular complications in this group. Further research is necessary to define the epidemiology and risk factors of premature CAD in survivors of pediatric cancers, and to determine whether candidate genes for cardiovascular disease in the general population are also susceptibility genes in this vulnerable population. Pediatr Blood Cancer 2007;48:738–741. © 2007 Wiley‐Liss, Inc.
A rapid TLC autographic method for the detection of glucosidase inhibitors
Authors: Salazar Mario O. , Furlan Ricardo L. E. 
Published: February 2007

AbstractA new bioautographic assay suitable for the localisation of β‐glucosidase inhibitors present in a complex matrix is described. Enzyme activity was detected using esculin as the substrate to produce esculetin, which reacts with ferric ion to form a brown complex. Copyright © 2007 John Wiley & Sons, Ltd.
Disconnection of the organic moiety in chromium and tungsten complexes [(dithiin)M(CO)5]
Authors: Granados Alejandro M. , Fracaroli Alejandro M. , Kreiker Jeronimo , de Rossi Rita H. 
Published: February 2007

AbstractThe reaction of 5‐alkylthio‐3H‐1,2‐dithiole‐3‐thione derivatives with Fischer alkoxy carbenes gives 1,3‐dithiin dithioorthoesters derivatives complexed with M(CO)5 (M = Cr or W). We report here that the dithiin derivative free of metal can be obtained by ligand exchange using acetonitrile, methanol, phenyl methyl sulfide or (Ph)3P. Methanol gives the best results from a preparative point of view. The reaction with acetonitrile was shown to be reversible and the kinetic of ligand exchange and the activation parameters were determined. From these data it is concluded that the mechanism is predominantly dissociative for M = Cr and it has some contribution of the associative mechanism for M = W. Copyright © 2007 John Wiley & Sons, Ltd.
The diurnal variation of warm‐frontal precipitation and thunderstorms
Authors: Dexter R. V. 
Published: February 2007

Abstract1. Inasmuch as there is a direct relation between the amount of potential instability in the warm air and the amount of precipitation subsequently produced as the air ascends the warm‐frontal surface, the maximum precipitation should be experienced at the time when the maximum potential instability is being realized.Maximum potential instability is developed in the warm air in contact with the ground in the late afternoon. But this instability is realized only after lifting, so that the time of maximum rainfall is postponed for six to ten hours, occurring in the late evening and early morning. This maximum reaches the edge of the precipitation area eight or more hours after development of the instability, thus increasing the width of the area in the late night and early morning hours. The development of cyclonic curvature which accompanies the realization of the potential instability in the ascending current may also be a contributing factor.2. Because latent instability is associated with potential instability, since if the latter is present, the former may develop through lifting, the maximum number of warm‐frontal thunderstorms likewise occurs in the late evening or early morning, six to ten hours after maximum potential instability has developed.
The temperature characteristics of different classes of air over the British Isles in winter
Authors: Belasco J. E. 
Published: February 2007

AbstractHitherto, for synoptic and climatic purpose, means of temperature at the surface, and in the upper air, have been obtained without regard to the different classes of air masses, the means being for all masses combined.With the object of obtaining a greater insight into the structure of the atmosphere, it is pertinent to inquire what are the difference between (i) the vertical distribution of temperature, and (ii) the temperature near the surface of the earth, in the different classes of air which cross the British Isles.This investigation gives, for the winter season (December, January, and February combined), for 12 different classes of air over the British Isles: (i) the average and extreme temperatures, the lapse rates and the degree of thermal stability at a number of levels in the atmosphere, and the heights of the 32°F. and 8°F. isotherms; (ii) the daily maximum and minimum temperatures, the mean temperature, and daily range of temperature at the surface at Kew during the 24‐hour period, 0‐24 h., on days when no important change of air mass occurred during this period. The levels in the atmosphere for which values have been obtained are 1,000, 2,000, 3,000, 5,000, 10,000, 15,000, and 20,000 feet. Over 600 upper air ascents, chosen for the most part during the winters of 1930‐31 to 1943‐44, and 1,000 surface maximum and minimum temperatures at Kew during the winters 1924‐25 to 1943‐44 have been used. For comparison, and to obtain an estimate of the changes of temperature and stability, means of temperature at the same levels in the atmosphere were obtained over western Russia in Siberian air, and over the Icelandic and Azores regions in direct polar air and in tropical air. The reality of the difference of temperature between the various classes of air chosen has been examined. A discussion of the physical problems raised in this paper is reserved for another paper.
On the frictional influence of horizontal wind shear on vertical motion
Authors: Priestley C. H. B. 
Published: February 2007

AbstractIt is suggested that a reason for the association between anticyclonic vorticity and subsidence lies in the divergence produced by the frictional forces when a strong horizontal wind shear is present. In particular the region just to the south of a strong westerly upper wind (northern latitudes) is favourable for subsidence.A case in which such conditions remained steady for five days has been examined quantitatively, and it is found that a subsidence velocity of a few centimetres per second is accounted for by assuming an isentropic turbulent interchange coefficient (K) of 5 × 109 cms2/sec. This is the value found by Rossby and independently by Grimminger in investigation of other phenomena on a similar scale.The frictional divergence depends on the third space derivative of velocity across the current, and so can only be obtained when the velocity field is mapped in very exact detail. Scope for practical application of this theory in synoptic work is therefore limited.
A theoretical note on some errors in estimating the curvatures of air trajectories and streamlines
Authors: Hogben G. L. 
Published: February 2007

AbstractThis note discusses the theoretical aspects of the errors in measuring curvature due

to taking streamlines as trajectories
to taking isobars as streamlines
to combining these errors by taking isobars as trajectories.
It is shown that, in addition to a scale factor error associated with movement of the isobaric and streamline systems (this has already been noted by other writers), there are errors associated with

The difluence of the isobars and streamlines
The rate of distortion of the systems
The angle between isobar and wind.
By choosing the right place in the isobar and streamline fields some or all of these errors may be avoided. Otherwise any one of them may be significant.
On the application of the richardson criterion to large‐scale turbulence in the free atmosphere
Authors: Petterssen Sverre , Swinbank W. C. 
Published: February 2007

AbstractA brief report on an investigation into the relationship between the wind shear and the static stability of the air in the layer immediately below the tropopause was presented to the Meteorological Research Committee in October 1942 (Swinbank, M.R.P. 51, unpublished). In the course of the ensuing discussion, members of the M.R.C. suggested that the investigation should be extended to cover the entire troposphere. This has been done particularly with a view to finding empirical relationships between stability and wind shear and comparing these with the results obtained by applying the Richardson criterion to actual observations. A further demand for investigating this problem arose in connection with an investigation of the turbulence conditions that obtain near the tropopause.In the present investigation use has been made of the reports from the British radio‐sonde stations for the period December 1942 to March 1943. The accuracy of the D/F method of determining the wind in the free atmosphere depends to a large extent upon the geometry of each case, and a tolerance figure is allotted to each observation assessing the accuracy. Only reports of the highest degree of accuracy (i.e. vector errors less than 5 km/hour) have been used in this investigation. In all, 1,556 simultaneous observations of lapse rate and wind shear have been investigated.The observations have been grouped according to levels, and the results are illustrated in 12 diagrams in which lapse rate is the abscissa and wind shear the ordinate. The diagrams contain also the limiting curve between decrease and increase in turbulence as computed from Richardson's criterion. Since wind observations are made at intervals of 50 millibars, the diagrams represent the observed relationship between the mean wind shear and the mean lapse rate through layers of 50 mb. depth. The limiting curve in these diagrams would then represent the limit between the conditions that determine decrease and increase in the large‐scale turbulence of the atmosphere.The diagrams show that, with very few exceptions, for any degree of stability the observed wind shear is less than that required by Richardson's theory to cause the turbulence to increase.If the assumptions underlying the theory were correct and applicable to large‐scale turbulence, the diagrams would indicate that large‐scale turbulence almost invariably tends to decrease. Since this result appears improbable, it is shown that agreement between theory and observation can be obtained by dropping one of the assumptions made by Richardson; namely, that the coefficient.
Dynamical control of atmospheric pressure: II—the size of pressure systems
Authors: Priestley C. H. B. 
Published: February 2007

AbstractA result from a previous paper (Priestley 1947) indicates the existence of a broad upper limit to the size of pressure systems, and a lower limit to the distance separating the centres of two significant closed pressure systems. The pressure field has thus an inherent scale of pattern which varies with latitude, imposed by the essential geometry and dynamics of atmospheric flow. Orders of magnitude deduced theoretically agree well with experience. The implications contribute to an understanding of the mechanism of the mean global circulation.
Note on the diurnal and semi‐diurnal pressure variation in Rhodesia
Authors: Sellick N. P. 
Published: February 2007

AbstractThe mean annual amplitude and phase of the diurnal and semi‐diurnal waves of barometric pressure at stations in Rhodesia and Nyasaland are given and it is shown that the amplitude of the semi‐diurnal wave, corrected according to Simpson's formula, exhibits a striking uniformity.
Some problems in radio meteorology
Authors: Booker H. G. 
Published: February 2007

AbstractRefraction of radio waves of wavelength less than about ten metres in the troposphere is a phenomenon usually associated with quite steep inversions of temperature and lapses of humidity within the first few thousand feet of the atmosphere and often within the first hundred feet. A radio ray may be bent downwards with a curvature exceeding the curvature of the earth either by an inversion of temperature exceeding about 5°F./100 ft. or by a lapse of humidity exceeding about 1/2 gm./kg./100 ft., or by a combination of the two. To cause marked unorthodox radio propagation these steep gradients need to be maintained through a layer of atmosphere whose thickness varies from say 50 ft. to 500 ft. depending on the radio wavelength under consideration. Generally speaking, the lower in the atmosphere the gradients occur the more striking is the phenomenon or radio refraction, and steep gradients at heights above about 5,000 ft. are not usually of great interest.The obvious meteorological phenomena likely to cause radio refraction are nocturnal radiation‐inversions over land, advection‐inversions caused by warm dry air over land moving out over sea, and low subsidence‐inversions. High subsidence‐inversions are not usually a direct cause of radio refraction; their presence may however indicate weather conditions favourable to development of radiation or advection‐inversions.The meteorological problem is to specify the profiles of temperature and humidity associated with these phenomena at least with sufficient accuracy to state whether the above‐mentioned gradients are exceeded, and if so between what intervals of height. Moreover it is necessary to be able to do this not merely in a special experiment but also from the ordinary data available in synoptic meteorology. It is suggested that the way to do this is to formulate a satisfactory theory of how the profiles of temperature and humidity arise, and then to check the theory carefully by experiment. The upshot should be a means of specifying the profiles in terms of parameters measuring the stability of the air, the windspeed, and so on, and these should be ascertainable from ordinary meteorological data.The application of the conjugate power‐law theory of eddydiffusion to the problem is described, as well as a comparison which had been made with observed profiles of temperature and humidity. The comparison, although satisfactory in some respects, seems to indicate that the profile‐index involved in the theory shows more signs of depending on the degree to which the diffusion‐process has developed than on the stability of the air. It is suggested that what is required is a theory in which the coefficient of eddy‐diffusion increases linearly from zero at ground level to a maximum at no great height, and then decreases again.
Theory of waves in the lee of mountains
Authors: Scorer R. S. 
Published: February 2007

AbstractThe disturbance in an air current, whose velocity may vary with height, caused by irregularities in the ground, is obtained. For a wave‐like corrugation of the ground of wavelength 2π/k, small enough for the earth's rotation to be neglected, the stream function of the disturbance satisfies Ψ″ – (g/c2 +β) Ψ + (gβ/U2 – U″/U – k2) Ψ = 0(12)Some circumstances in which waves may have large amplitude only in the lower layers of the atmosphere are described. In order that such waves may occur over level ground in the lee of mountains the parameter l must normally decrease upwards, where l2 = gβ/U2 – U″/U (13)With two layers, the lower of depth h, these waves can occur if l1 2 – l2 2 > π2/4h2 (17)Fourier's integral theorem is used to obtain the flow in two instances. Fig. 3 shows the wave due to a single long ridge in a stream in which the wind is stronger at higher levels. Fig. 5 shows the flow of a shallow current descending from a plateau, the air being calm above.Nodal surfaces, as in Fig. 5, occur only when the depth of the layer exceeds a critical value, depending on the details of wind speed and temperature.The well‐known cloud phenomena associated with the waves are briefly described in section 6, and in section 7 the effect of isolated mountains rather than long ridges is considered.The theory is only valid for streamline, dry, isentropic, inviscid. flow in which the disturbance is only a small proportion of the wind velocity.
The vertical temperature gradient in the lower atmosphere under daylight conditions
Authors: Tait G. W. C. 
Published: February 2007

AbstractA relationship is derived between the vertical temperature gradient in the lower atmosphere during daylight hours and other meteorological quantities. Pyrheliometer records of solar radiation taken simultaneously with temperature gradient measurements gave the empirical relation T1–T2 =(0.4–41) log10 Z1/Z2 where T is the temperature in °F at height Z cm and I the insolation in cal cm−2/min. This equation was converted into a more useful form by expressing the insolation in terms of state of sky, latitude and time. The relationship disclosed was found to be independent of wind speed (at least up to speeds of 24 mi/hr). The data on which the relation is based is confined to observations at Suffield, a semi‐arid locality. A brief discussion of other conditions of exposure suggests that some generality of application may be permissible.