2,396 research outputs found
Profile in Public Integrity: Laurence Cockcroft
No full textA development economist and author, Laurence Cockcroft co-founded Transparency International in 1993 and served as Chairman of the U.K. chapter from 2000-2008. Cockcroft has drawn from his experience with Transparency International to author Global Corruption, as well as Unmasked: Corruption in the West, recently published in the U.K. and the U.S. by I.B. Tauris
Cockcroft
No full textSir John Cockcroft speaking on "Science and Society" at the afternoon session of Cooper Union's 100th Anniversary Convocation, November 2, 1959. Cooper Union President Edwin S. Burdell is seated at rear.image/tif; 100-117 Crockcroft in GH.tif; 30,169,978 bytesHP Scanjet 8300; 600ppi; 8-bit grayscaleMitsuko Brook
Unions of Cockcroft two-complexes
No full textA combinatorial group-theoretic hypothesis is presented that serves as a necessary and sufficient condition for a union of connected Cockcroft two-complexes to be Cockcroft. This hypothesis has a component that can be expressed in terms of the second homology of groups. The hypothesis is applied to the study of the third homology of groups given by generators and relators. 1991 Mathematics subject classification: Primary 57M20, Secondary 20F05, 20J05 1 Introduction It was observed by Cockcroft [5] that if a two-complex K (that is, a twodimensional CW complex) is a subcomplex of an aspherical two-complex, then for any basepoint z 2 K, the Hurewicz map h : ß 2 (K; z) ! H 2 K is trivial. In other words, each spherical map S 2 ! K is homologically trivial. Two-complexes with this latter property are therefore said to be Cockcroft. In this note, necessary and sufficient conditions are given for a union K of subcomplexes K r and K s to be Cockcroft. A necessary condition is that each of ..
Cockcroft properties of Thompson's group
No full textIn a study of the word problem for groups, R. J. Thompson considered a certain group F of self-homeomorphisms of the Cantor set and showed, among other things, that F is finitely presented. Using results of K. S. Brown and R. Geoghegan, M. N. Dyer showed that F is the fundamental group of a finite two-complex Z2 having Euler characteristic one and which is Cockcroft, in the sense that each map of the two-sphere into Z2 is homologically trivial. We show that no proper covering complex of Z2 is Cockcroft. A general result on Cockcroft properties implies that no proper regular covering complex of any finite two-complex with fundamental group F is Cockcroft.</p
Assessment of GFR by four methods in adults in Ashanti, Ghana : the need for an eGFR equation for lean African populations
No full textBackground. Equations for estimating glomerular filtration rate (GFR) have not been validated in Sub-Saharan African populations, and data on GFR are few.
Methods. GFR by creatinine clearance (Ccr) using 24-hour urine collections and estimated GFR (eGFR) using the four-variable Modification of Diet in Renal Disease (MDRD-4)[creatinine calibrated to isotope dilution mass spectrometry (IDMS) standard], Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) and Cockcroft–Gault equations were obtained in Ghanaians aged 40–75. The population comprised 1013 inhabitants in 12 villages; 944 provided a serum creatinine and two 24-hour urines. The mean weight was 54.4 kg; mean body mass index was 21.1 kg/m2.
Results. Mean GFR by Ccr was 84.1 ml/min/1.73m2; 86.8% of participants had a GFR of 60 ml/min/1.73m2. Mean MDRD-4 eGFR was 102.3 ml/min/1.73m2 (difference vs. Ccr, 18.2: 95% CI: 16.8–19.5); when the factor for black race was omitted, the value (mean 84.6 ml/min/1.73m2) was close to Ccr. Mean CKD-EPI eGFR was 103.1 ml/min/1.73m2, and 89.4 ml/min/1.73m2 when the factor for race was omitted. The Cockcroft–Gault equation underestimated GFR compared with Ccr by 9.4 ml/min/1.73m2 (CI: 8.3–10.6); particularly in older age groups. GFR by Ccr, and eGFR by MDRD-4, CKD-EPI and Cockcroft–Gault showed falls with age: MDRD-4 5.5, Ccr 7.7, CKD-EPI 8.8 and Cockcroft–Gault 11.0 ml/min/1.73m2/10 years. The percentage of individuals identified with CKD stages 3–5 depended on the method used: MDRD-4 1.6% (7.2 % without factor for black race; CKD-EPI 1.7% (4.7% without factor for black race), Ccr 13.2% and Cockcroft–Gault 21.0%.
Conclusions. Mean eGFR by both MDRD-4 and CKD-EPI was considerably higher than GFR by Ccr and Cockcroft–Gault, a difference that may be attributable to leanness. MDRD-4 appeared to underestimate the fall in GFR with age compared with the three other measurements; the fall with CKD-EPI without the adjustment for race was the closest to that of Ccr. An equation tailored specifically to the needs of the lean populations of Africa is urgently needed. For the present, the CKD-EPI equation without the adjustment for black race appears to be the most useful
The Cockcroft Institute Wakefields Interest Group
No full textThe Cockcroft Institute is a newly created international centre for Accelerator
Science and Technology in the UK. It is a joint venture between the Universities of
Lancaster, Liverpool and Manchester, and the Science and Technology Facilities
Council. The Cockcroft Institute has a large expertise base in Wakefields and
Impedances which is linked through the Cockcroft Institute Wakefields Interest Group.
Members of this group have experience in wakefields in linear colliders, ring colliders,
light sources as well as generic fundamental research and focus on a wide range of
specialist areas. In this article we summarize the work performed in this important field
of research at the Cockcroft Institute
150 Kv Cockcroft-Walton Type Particle Accelerator
No full textDetails of the 150KV Cockcroft-Walton type particle accelerator, which has been constructed in this laboratory, are given. Use of radio-frequency ion-source, and 250KV isolation transformer for supplying voltage to the various circuits in the ion-source head, are its main features. A steady current of protons of more than 100 micro-amperes at the target has been obtained
Effects of non-steroidal antininflammatory drugs on prostacyclin and thromboxane biosynthesis in patients with mild essential hypertension
No full text1. The effects of non-steroidal anti-inflammatory drugs (NSAID) on prostacyclin and thromboxane biosynthesis and on blood pressure were determined in 46 patients with mild essential hypertension. Patients who had abstained from antihypertensive therapy for 2 weeks before study were treated with either aspirin, ibuprofen, sulindac or placebo for 7 days. 2. Excretion rates of 2,3-dinor-6-oxo-prostaglandin (PG) F1 alpha, 6-oxo-PGF1 alpha, 2,3-dinorthromboxane (TX) B2 and TXB2 were measured as indices of prostacyclin and TXA2 biosynthesis. Samples were assayed using immunoaffinity chromatography and gas chromatography/electron capture chemical ionisation mass spectrometry. 3. Aspirin and ibuprofen reduced urinary excretion of all prostacyclin- and thromboxane-derived products. Sulindac inhibited excretion of 2,3-dinor-6-oxo-PGF1 alpha, 6-oxo-PGF1 alpha and 2,3-dinor-TXB2, but had no significant effect on TXB2. 4. Systolic blood pressure increased in the ibuprofen-treated group when compared with the placebo group. There were no other significant changes in systolic or diastolic pressure in any of the treatment groups. Among the patients as a whole, there was a significant negative correlation between change in blood pressure and change in excretion of the prostacyclin-derived but not of the thromboxane-derived products. 5. We conclude that, in patients with mild essential hypertension, neither sulindac nor aspirin (in the doses used) selectively spares prostacyclin biosynthesis by the kidney. The significant relationship between increase in blood pressure and reduction in prostacyclin biosynthesis favours the possibility that in individuals who become hypertensive, prostacyclin biosynthesis determines, in part, the severity of the hypertensive state
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