W Ellison | None (Private) (original) (raw)
Papers by W Ellison
Journal des maladies vasculaires, 1988
The manual interpretation of identical occlusive venous plethysmography curves by different techn... more The manual interpretation of identical occlusive venous plethysmography curves by different technicians is subject to a wide variation. The object of this study is to verify this state of affairs and to propose an automatic calculation of the different parameters usually used: the percentage volume increase (delta V), the time taken to half empty (t V/2) and the maximal venous outflow (MVO). We compared the variations, due to the operators, in the measurement of the parameters characterising identical curves obtained by occlusive venous plethysmography. Sixty curves from 30 patients, were photocopied and each was measured independently by four different operators. The results were compared with the measurements obtained automatically from a micro-computer connected to the plethysmograph. The measurements of the percentage volume increase and the time taken to half empty differed among the operators and the computer by less than 2%. However, the maximal venous outflow was subject to ...
Journal des maladies vasculaires, 1985
One hundred and twenty nine in situ vein bypasses have been reviewed with a five year follow-up. ... more One hundred and twenty nine in situ vein bypasses have been reviewed with a five year follow-up. Cumulative patency rates at five year are 71% (+/- 21%) for above-knee femoro-popliteal bypasses, 69% (+/- 11.5%) for below-knee anastomosis and 94% (+/- 35%) when distal anastomosis is performed on tibial or peroneal vessel. Global cumulative graft patency rate is 71% (+/- 9.4%). It is 72% (+/- 11%) in limb salvage.
Annales medico-psychologiques, 1990
Depuis 60 ans, une cinquantaine d'etudes ont trouve, dans l'hemisphere nord, un exces de ... more Depuis 60 ans, une cinquantaine d'etudes ont trouve, dans l'hemisphere nord, un exces de naissances hivernales des schizophrenes. Une enquete personnelle, la premiere de ce type en France, portant sur 3944 schizophrenes des hopitaux psychiatriques francais (sauf region parsienne) confirme, pour les patients nes apres 1945, l'exces de naissances pendant les premiers mois de l'annee et un deficit pendant le deuxieme semestre. Revue de la litterature
Here the analysis of the results of a multicentered prospective epidemiologic study that has coun... more Here the analysis of the results of a multicentered prospective epidemiologic study that has counted only the new cases of chronic atherosclerosis obliterans of the lower extremities. Included have been 989 patients (659 men and 330 women). Critical analysis of data allows a comparative study between the sexes. Thus, specifics of arteriopathy among women can be drawn. It appears that they are only the consequences of the fact that men and women reflect a different level of tobacco use in the two populations.
Annales médico-psychologiques, 1990
... 1990 Oct;148(8):698-708. [Survey on the seasonal changes in the birth of patients with schizo... more ... 1990 Oct;148(8):698-708. [Survey on the seasonal changes in the birth of patients with schizophrenia]. [Article in French]. Bourgeois M, Cassou de Saint-Mathurin R, Verdoux H, Ellison W. IPSO, Centre Carreire, Bordeaux. PMID: 2092600 [PubMed - indexed for MEDLINE]. ...
Radio Science, 1998
As part of a measuring program dedicated to the analysis of the dielectric properties of seawater... more As part of a measuring program dedicated to the analysis of the dielectric properties of seawater in the frequency range 3-89 GHz, a new dielectric permittivity model based on the standard Debye theory has been developed for remote sensing applications over the ocean below 40 GHz, together with polynomial interpolations at the millimeter frequencies 85.5 and 89 GHz. The aim of this paper is to test the relevance of these new dielectric measurements through statistical comparisons of radiative transfer predictions with satellite and airborne radiometric data between 18 and 89 GHz. A radiometric sensitivity analysis to the permittivity measurement errors is proposed, which yields a sea surface brightness temperature accuracy of at least 0.5 K below 20 GHz, 1 K at 24 GHz, and 1.5 K at 37 and 89 GHz. At frequencies less than 40 GHz, superiority of the revised Debye model is pointed out over the most commonly used model of Klein and Swift [1977]. At millimeter frequencies the new permittivity expressions deviate significantly from the standard Debye predictions, especially at low temperature, suggesting the influence of a second ``high-frequency'' Debye relaxation. Our comparisons with radiometric data at 89 GHz and in the channel 85.5V of the special sensor microwave imager tend to support this hypothesis. The results emphasize the importance of an adequate modeling of the complex permittivity of seawater as input to the surface emissivity models, at any frequency of the microwave spectrum, and augur interesting outputs in both in-flight calibration and interpretation of satellite data.
Hormone and Metabolic Research, 1992
Journal de Physique III, 1994
Journal of Number Theory, 1971
BJA: British Journal of Anaesthesia, 1993
In order to design a new, preformed tracheal tube adapted to the shape of the upper respiratory t... more In order to design a new, preformed tracheal tube adapted to the shape of the upper respiratory tract, we have undertaken an anthropometric study from lateral x-rays of the neck in 130 patients with the head in a fixed position. In order to assess different clinical situations, we studied three groups of patients: group 1 = sitting, no tracheal tube; group 2 = supine, no tracheal tube; group 3 = supine, trachea intubated. We defined a standard coordinate system and determined mathematical curves for segments of the upper respiratory tract by a polynomial regression method. With these data it was possible to study the effects of physiological variations on the shape of the curves. It was then possible to determine at which region changes occur and the factors influencing these changes. We found that the relative position of the larynx was constant, whereas the hypopharynx exhibited the greatest change with the position of the head. These observations should allow us to construct a new, preformed tracheal tube with elastic compliance properties to fit the changes occurring in the region of the hypopharynx.
Page 1. ■Hi Thermal Microwave Radiation: Applications for Remote Sensing Edited by C Matzler Page... more Page 1. ■Hi Thermal Microwave Radiation: Applications for Remote Sensing Edited by C Matzler Page 2. IET ELECTROMAGNETIC WAVES SERIES 52 Series Editors: Professor PJB Clarricoats Professor EV Jull Thermal Microwave Radiation: Applications for Remote Sensing ...
Neurology, 1998
To the Editor: We read with interest the article by Sulway et a1. l The authors report that 47 ye... more To the Editor: We read with interest the article by Sulway et a1. l The authors report that 47 years after their liberation, WW I1 prisoners of war (POWs) of the Japanese were not demented more frequently than non-POW veterans. In addition, they report that POWs and non-POW veterans do not differ significantly in cognitive performance on some neuropsychologic tests. Their conclusions could have serious consequences for POWs with compensation claims, and some possible limitations of their study should be stressed.
Acta Arithmetica, 2013
To "Ian"Cassels on his 90 th birthday 1. Introduction. The classic Waring problem for Z has a vas... more To "Ian"Cassels on his 90 th birthday 1. Introduction. The classic Waring problem for Z has a vast literature (for a glimpse see [6], [18]). The solution of the corresponding problems associated with expressing the elements of a field K as the sum of k th powers is much less complete. For k = 2 we have Artin's characterisation that K is a sum of squares if and only if > 0 for all orderings of K. For k an even number, Becker [1] extended Artin's ideas to characterise K as a sum of k th powers if and only if > 0 for all orderings of K and k () for all valuations of K with a formally real valuation field. Denote by P(K, k) the a K which are sums of k th powers of elements of K, by P + (K, k) the set of a K which are sums of k th powers of totally positive elements of K. We are interested in deciding whether or not there exist integers w(K, k) and g(K, k) such that: a P(K, k) implies that a is the sum of at most w(K, k) k th powers; a P + (K, k) implies that a is the sum of at most g(K, k) totally positive k th powers. Neither Artin's nor Becker's characterisations gives any information about the existence of w(k, K) or g(K, k). This is to be expected since there are many fields for which w(K, 2) = , which implies that w(K, 2k) = . The integer w(K, 2) is called the Pythagorean number of K. For a given integer s, one can construct fields such that w(K, 2) = s [9]. However, for a given field it is usually a difficult problem to determine its Pythagorean number. For an algebraic number field K it is a classic result that w(K, 2) 4 and w(K(X), 2) 5 [16, 10]. For n 2, 5+n w(K(X 1 , …, X n), 2) 2 n+1 [2, 5]. If R is a real closed field, w(R(X), 2) = 2, w(R(X 1 , X 2), 2) = 4 [3] and for n 3, 1+ n w(R(X 1 , …, X n), 2) 2 n [2, 14, 15]. We will show that if w(K, 2) is finite and provided that the k th powers are dense (in a sense described explicitly in theorem 3) in K, then w(K, k) is also finite for k > 2. The proofs are constructive, but the implied upper bounds for w(K, k) are large. This is to be expected since the method of proof does not use any deep arithmetical or algebraic properties of the field K.
Drafts by W Ellison
The connectivity properties of the hydrogen-bond network of liquid water are determined along the... more The connectivity properties of the hydrogen-bond network of liquid water are determined along the liquid-vapour coexistence curve using a simple combinatorial model. The succeeding papers will extend the results over the whole phase diagram of liquid water and the results will then be used to provide interpolation functions for a number of bulk properties of liquid water such as compressibility, viscosity, permittivity etc.
Journal des maladies vasculaires, 1988
The manual interpretation of identical occlusive venous plethysmography curves by different techn... more The manual interpretation of identical occlusive venous plethysmography curves by different technicians is subject to a wide variation. The object of this study is to verify this state of affairs and to propose an automatic calculation of the different parameters usually used: the percentage volume increase (delta V), the time taken to half empty (t V/2) and the maximal venous outflow (MVO). We compared the variations, due to the operators, in the measurement of the parameters characterising identical curves obtained by occlusive venous plethysmography. Sixty curves from 30 patients, were photocopied and each was measured independently by four different operators. The results were compared with the measurements obtained automatically from a micro-computer connected to the plethysmograph. The measurements of the percentage volume increase and the time taken to half empty differed among the operators and the computer by less than 2%. However, the maximal venous outflow was subject to ...
Journal des maladies vasculaires, 1985
One hundred and twenty nine in situ vein bypasses have been reviewed with a five year follow-up. ... more One hundred and twenty nine in situ vein bypasses have been reviewed with a five year follow-up. Cumulative patency rates at five year are 71% (+/- 21%) for above-knee femoro-popliteal bypasses, 69% (+/- 11.5%) for below-knee anastomosis and 94% (+/- 35%) when distal anastomosis is performed on tibial or peroneal vessel. Global cumulative graft patency rate is 71% (+/- 9.4%). It is 72% (+/- 11%) in limb salvage.
Annales medico-psychologiques, 1990
Depuis 60 ans, une cinquantaine d'etudes ont trouve, dans l'hemisphere nord, un exces de ... more Depuis 60 ans, une cinquantaine d'etudes ont trouve, dans l'hemisphere nord, un exces de naissances hivernales des schizophrenes. Une enquete personnelle, la premiere de ce type en France, portant sur 3944 schizophrenes des hopitaux psychiatriques francais (sauf region parsienne) confirme, pour les patients nes apres 1945, l'exces de naissances pendant les premiers mois de l'annee et un deficit pendant le deuxieme semestre. Revue de la litterature
Here the analysis of the results of a multicentered prospective epidemiologic study that has coun... more Here the analysis of the results of a multicentered prospective epidemiologic study that has counted only the new cases of chronic atherosclerosis obliterans of the lower extremities. Included have been 989 patients (659 men and 330 women). Critical analysis of data allows a comparative study between the sexes. Thus, specifics of arteriopathy among women can be drawn. It appears that they are only the consequences of the fact that men and women reflect a different level of tobacco use in the two populations.
Annales médico-psychologiques, 1990
... 1990 Oct;148(8):698-708. [Survey on the seasonal changes in the birth of patients with schizo... more ... 1990 Oct;148(8):698-708. [Survey on the seasonal changes in the birth of patients with schizophrenia]. [Article in French]. Bourgeois M, Cassou de Saint-Mathurin R, Verdoux H, Ellison W. IPSO, Centre Carreire, Bordeaux. PMID: 2092600 [PubMed - indexed for MEDLINE]. ...
Radio Science, 1998
As part of a measuring program dedicated to the analysis of the dielectric properties of seawater... more As part of a measuring program dedicated to the analysis of the dielectric properties of seawater in the frequency range 3-89 GHz, a new dielectric permittivity model based on the standard Debye theory has been developed for remote sensing applications over the ocean below 40 GHz, together with polynomial interpolations at the millimeter frequencies 85.5 and 89 GHz. The aim of this paper is to test the relevance of these new dielectric measurements through statistical comparisons of radiative transfer predictions with satellite and airborne radiometric data between 18 and 89 GHz. A radiometric sensitivity analysis to the permittivity measurement errors is proposed, which yields a sea surface brightness temperature accuracy of at least 0.5 K below 20 GHz, 1 K at 24 GHz, and 1.5 K at 37 and 89 GHz. At frequencies less than 40 GHz, superiority of the revised Debye model is pointed out over the most commonly used model of Klein and Swift [1977]. At millimeter frequencies the new permittivity expressions deviate significantly from the standard Debye predictions, especially at low temperature, suggesting the influence of a second ``high-frequency'' Debye relaxation. Our comparisons with radiometric data at 89 GHz and in the channel 85.5V of the special sensor microwave imager tend to support this hypothesis. The results emphasize the importance of an adequate modeling of the complex permittivity of seawater as input to the surface emissivity models, at any frequency of the microwave spectrum, and augur interesting outputs in both in-flight calibration and interpretation of satellite data.
Hormone and Metabolic Research, 1992
Journal de Physique III, 1994
Journal of Number Theory, 1971
BJA: British Journal of Anaesthesia, 1993
In order to design a new, preformed tracheal tube adapted to the shape of the upper respiratory t... more In order to design a new, preformed tracheal tube adapted to the shape of the upper respiratory tract, we have undertaken an anthropometric study from lateral x-rays of the neck in 130 patients with the head in a fixed position. In order to assess different clinical situations, we studied three groups of patients: group 1 = sitting, no tracheal tube; group 2 = supine, no tracheal tube; group 3 = supine, trachea intubated. We defined a standard coordinate system and determined mathematical curves for segments of the upper respiratory tract by a polynomial regression method. With these data it was possible to study the effects of physiological variations on the shape of the curves. It was then possible to determine at which region changes occur and the factors influencing these changes. We found that the relative position of the larynx was constant, whereas the hypopharynx exhibited the greatest change with the position of the head. These observations should allow us to construct a new, preformed tracheal tube with elastic compliance properties to fit the changes occurring in the region of the hypopharynx.
Page 1. ■Hi Thermal Microwave Radiation: Applications for Remote Sensing Edited by C Matzler Page... more Page 1. ■Hi Thermal Microwave Radiation: Applications for Remote Sensing Edited by C Matzler Page 2. IET ELECTROMAGNETIC WAVES SERIES 52 Series Editors: Professor PJB Clarricoats Professor EV Jull Thermal Microwave Radiation: Applications for Remote Sensing ...
Neurology, 1998
To the Editor: We read with interest the article by Sulway et a1. l The authors report that 47 ye... more To the Editor: We read with interest the article by Sulway et a1. l The authors report that 47 years after their liberation, WW I1 prisoners of war (POWs) of the Japanese were not demented more frequently than non-POW veterans. In addition, they report that POWs and non-POW veterans do not differ significantly in cognitive performance on some neuropsychologic tests. Their conclusions could have serious consequences for POWs with compensation claims, and some possible limitations of their study should be stressed.
Acta Arithmetica, 2013
To "Ian"Cassels on his 90 th birthday 1. Introduction. The classic Waring problem for Z has a vas... more To "Ian"Cassels on his 90 th birthday 1. Introduction. The classic Waring problem for Z has a vast literature (for a glimpse see [6], [18]). The solution of the corresponding problems associated with expressing the elements of a field K as the sum of k th powers is much less complete. For k = 2 we have Artin's characterisation that K is a sum of squares if and only if > 0 for all orderings of K. For k an even number, Becker [1] extended Artin's ideas to characterise K as a sum of k th powers if and only if > 0 for all orderings of K and k () for all valuations of K with a formally real valuation field. Denote by P(K, k) the a K which are sums of k th powers of elements of K, by P + (K, k) the set of a K which are sums of k th powers of totally positive elements of K. We are interested in deciding whether or not there exist integers w(K, k) and g(K, k) such that: a P(K, k) implies that a is the sum of at most w(K, k) k th powers; a P + (K, k) implies that a is the sum of at most g(K, k) totally positive k th powers. Neither Artin's nor Becker's characterisations gives any information about the existence of w(k, K) or g(K, k). This is to be expected since there are many fields for which w(K, 2) = , which implies that w(K, 2k) = . The integer w(K, 2) is called the Pythagorean number of K. For a given integer s, one can construct fields such that w(K, 2) = s [9]. However, for a given field it is usually a difficult problem to determine its Pythagorean number. For an algebraic number field K it is a classic result that w(K, 2) 4 and w(K(X), 2) 5 [16, 10]. For n 2, 5+n w(K(X 1 , …, X n), 2) 2 n+1 [2, 5]. If R is a real closed field, w(R(X), 2) = 2, w(R(X 1 , X 2), 2) = 4 [3] and for n 3, 1+ n w(R(X 1 , …, X n), 2) 2 n [2, 14, 15]. We will show that if w(K, 2) is finite and provided that the k th powers are dense (in a sense described explicitly in theorem 3) in K, then w(K, k) is also finite for k > 2. The proofs are constructive, but the implied upper bounds for w(K, k) are large. This is to be expected since the method of proof does not use any deep arithmetical or algebraic properties of the field K.
The connectivity properties of the hydrogen-bond network of liquid water are determined along the... more The connectivity properties of the hydrogen-bond network of liquid water are determined along the liquid-vapour coexistence curve using a simple combinatorial model. The succeeding papers will extend the results over the whole phase diagram of liquid water and the results will then be used to provide interpolation functions for a number of bulk properties of liquid water such as compressibility, viscosity, permittivity etc.