Search

The aim of the UK FEL project is to study the characteristics of a single-pass FEL over a wide operating range, using a four-section 5 m wiggler yielding a maximum K value of 2.7. The laser is driven by the 165 MeV Kelvin Laboratory linac. It has a design operating wavelength range of 2–20 μm, although higher harmonics are also under investigation. We report direct measurement of optical gain using a cw CO2 laser between 9 and 11 μm. Simultaneous spectra are obtained of both gain and spontaneous emission as a function of linac energy or wiggler field as the tuning parameter. The linewidth obtained is close to that expected for homogeneous broadening, and the gain is consistent with that predicted theoretically for the current available. Strong enhancement of both spontaneous emission and measured gain is obtained in the presence of a high-Q FEL cavity, as expected by simple considerations of optical confinement. These results imply that despite the shortness of our macropulse (∼ 2.5 μm), it will be possible to diagnose buildup to oscillation from an injected signal.

Elastic electron scattering cross sections from the isotopes 24Mg, 25Mg and 26Mg have been measured in the momentum transfer range 0.20-1.15 fm-1. The individual RMS radii and also the differences between the isotopes are investigated. The measured form factors are compared with the predictions of an extended Nilsson model calculation.

Inelastic electron scattering form factors for excitation of states up to 2.4 MeV in 114Cd have been obtained in the momentum-transfer range between 0.37 and 1.09 fm-1. The 21+ quadrupole moment and 22+ radiative transition rates are deduced using a vibrational model in which one- and two-phonon states are mixed. The results obtained are in excellent agreement with recent reorientation effect measurements. Inclusion of higher momentum transfer data favours a 3- assignment for the 1.957 MeV level. The 4+ level at 2.35 MeV is shown to have an enhanced transition rate, making it a candidate for the single-phonon hexadecupole transition.

The energy compression system at the Glasgow 170 MeV electron linac is described. A system of three magnets plus a radio-frequency cavity is used to compress the linac energy spectrum by a factor of 5 to 15, depending on energy. Examples of compressed spectra are shown, and the effect of a phase shift in the compression cavity is demonstrated.

The current status of the UK FEL program is reviewed at the end of its second year. A description of the optical and electron beam diagnostics is given, and a preliminary study of spontaneous emission at harmonic frequencies is reported.

A collaboration of several universities and scientific centres is studying the characteristics of a single pass FEL over a wide operating range. Optimum gain performance has been selected in a highly broadened regime for the range 2–20 μm, but higher harmonics will also be measured. The facility has been constructed using the 165 MeV Kelvin linac, modified to improve its properties as an FEL source. A new beam transport system matches electrons through the 65 mm period undulator and also incorporates an electron spectrometer system of high accuracy. The 5 m magnet has four independent, identical sections for experimental flexibility and is remotely controllable to high field strength. Following studies of the electron beam properties, including emittance and alignment, spontaneous spectra have been recorded and gain measurements are now being attempted.

We have reviewed 106 fractures of the tibia with an intact fibula. Most patients were treated in above-knee plaster casts and allowed to walk. Only 2 fractures failed to unite and there were 4 refractures. In 27 patients (25 per cent) the fracture healed with more than 5 degrees of varus angulation. The cause of this deformity and its prevention are discussed.

Form factors for the inelastic scattering of electrons from 15N were measured for the excitation of the 6.32 MeV 3/2- state and of the 5.3 MeV 5/2+ 1/2+ doublet. The experimental data obtained resolve apparent discrepancies between the results deduced from the previous studies of 15N by electron scattering, and demonstrate that even large-basis shell-model calculations using the Kuo interaction do not produce realistic wavefunctions for these states.

Form factors for the inelastic scattering of electrons from the even-mass isotopes 110-116Cd were measured. The B(E2 spin up) and Q(21+) deduced from these data confirm the results of a recent measurement of these quantities carried out by Coulomb excitation.

The effect of food on the rate and extent of absorption of tolbutamide in diabetic patients was studied by varying the time of drug administration in relation to the ingestion of a standard meal. Serum levels of tolbutamide, insulin and glucose and related bioavailability parameters were compared following the administration of a single dose of tolbutamide 0.5 g to diabetic patients 30 min prior to and immediately before a standardized meal. A placebo dosage form was also administered to determine baseline glucose and insulin response to the meal. The 700 calorie standard meal was composed of 41% carbohydrate, 18% protein, and 41% fat. Administration of the drug with the meal resulted in a 6% (statistically significant) decrease in the extent of absorption, as determined by measurement of the area under the tolbutamide serum level-time curve from zero to infinity. Serum levels of tolbutamide were also significantly higher 0.5 h after drug administration when the drug was taken with the meal. Except for these two minor effects, no other differences between the drug treatments were observed in any other parameters of tolbutamide absorption or in the postprandial glucose and insulin serum levels. Therefore, the small differences found were judged to be clinically meaningless. These findings demonstrate that administration of tolbutamide 0.5 g tablets 30 min prior to or with a standard meal results in equivalent therapeutic actions.

The ground-state charge distributions of 28,29,30Si have been studied by elastic electron scattering and the results compared with those from muonic isotope shift work and other electron-scattering experiments. The 21+ state at 1.78 MeV in 28Si and the 21+ state at 2.24 MeV and 22+ state at 3.50 MeV in 30Si have been investigated by inelastic electron scattering and their form factors extracted.

An extensive collection of fossilized ovules, ovulate cupules, and cupuliferous branching systems from late Devonian deposits of eastern West Virginia is described and named Elkinsia polymorpha gen. et sp. nov. Elkinsia cupules are borne at the tips of cruciately forking axes that show a moderate level of overtopping. Cupules are 1.0-1.8 cm long and 0.6-1.2 cm in maximum diameter. The cupule is constructed of slender axes that fork twice to produce four quarters; each quarter terminates in one ovule and four sterile tips. Ovules are 3.5-7.0 mm long and isodiametric in transverse section, with an integument of 4-5 lobes that are fused together only in the basal third of the ovule. The nucellus is terminated by a large, dome-shaped pollen chamber that is surmounted by a tubular lagenostome. There is also evidence of a central column that indicates Elkinsia had hydrasperman reproduction. Elkinsia is compared to the other Devonian ovulate cupules Moresnetia zalesskyi, Archaeosperma arnoldii, Xenotheca devonic...

The excited states of 25Mg have been studied by inelastic electron scattering in the momentum transfer range 0.3 to 1.15 fm-1. The reduced transition probabilities and transition radii were measured for seven levels below 4.1 MeV excitation energy and the transition probabilities are shown to be more precise than existing measurements. A search for the hexadecupole strength to the 11/2+ levels in the vicinity of 5-6 MeV excitation energy was also carried out. The applicability of an extended Nilsson-model description for the ground-state band of 25Mg was also investigated by comparison with the known electromagnetic strengths, and, more crucially, by comparison with the measured form factors.

Electron scattering form factors have been measured for the excitation of 2.21 MeV ( 7 2 + ) 2.734 MeV ( 5 2 + ) and 3.00 MeV ( 9 2 + ) states in 27Al using values of momentum transfer between 0.31 and 1.05 fm−1. Reduced ground-state transition probabilities and transition radii are obtained for the 2.21 and 3.00 MeV states. Intermediate-coupling calculations are shown to reproduce the energy spectrum of 27A1 but not the transition matrix elements and the form factors. Much better agreement is obtained using a large basis shell-model calculation.

We describe the data acquisition and optical diagnostic systems of the UK free-electron laser. Measurements of optical gain are reported and the first attempt at oscillation with laser injection is described.

The following paper analyzes the horizontal equity implications of property taxation in Canada. We use five shifting assumptions in our analysis. Horizontal inequality indexes developed independent...

The elastic electron-scattering form factor, and inelastic form factors for the 21+ (0.434 MeV), 22+ (0.931 MeV) and 3- (2.046 MeV) states in 108Pd were measured. The ground-state charge distribution parameters were obtained from a phase-shifted analysis of the elastic form factor. Analysis of the 21+ and 22+ form factors in the anharmonic vibrator model yields the reduced transition probabilities and the 21+ quadrupole moment (Qx, x=21+) which is in excellent agreement with recent Coulomb reorientation measurements. The 3- form factor is well described by the assumption that this state is a pure octupole vibration.

Inelastic electron scattering form factors for the excitation of the 3/2- state at 6.32 MeV in 15N were measured. The experimental data obtained require (a) a momentum-transfer-dependent effective charge, in agreement with that predicted by coupling single-hole wavefunctions to a collective vibration of the 16O core, and (b) an effective magnetic moment having 0.7 times the single-particle value.

Detection of inelastically scattered alpha particles near 180° from the reaction 22Ne(α,α′)22Ne has been used to identify natural parity levels in 22Ne. Energy spectra were recorded for ten incident energies from 16.5–21.0 MeV in steps of 500 keV. Levels at 4.46, 5.52, and 5.92 MeV have been identified as having natural parity, leading to definite assignments of 2+, 4+, and 2+ respectively. Levels at 5.14 and 5.64 MeV have been identified as having unnatural parity, implying assignments of 2− and 3+ respectively. Tentative assignments are suggested for other levels, and the implications of the present assignments with regard to the identification of band structure in 22Ne are discussed.

The decays of two resonances in 23Na(p,γ)24Mg have been studied by γ–γ angular correlation methods. These resonances occur at proton energies of 1020 and 1318 keV and correspond respectively to levels in 24Mg at 12.671 and 12.957 MeV. In the latter case, the analysis of the data leads to an assignment of J = 1 to the level at 12.957 MeV. The angular correlation measurements confirm a previous assignment of J = 2 to the 12.671 MeV level and the information on magnetic substate populations obtained from the angular correlation analysis, together with a measurement of the angular distribution of the 12.671 to 8.86 MeV transition, yield an assignment of 2− to the 24Mg level at 8.86 MeV.

Staphylococcal colonization and infection were studied prospectively in infants, mothers and households after childbirth at home and in hospital. Infants were treated prophylactically with frequent applications of ‘Ster-zac’ hexachlorophane dusting powder. Some were treated in addition with ‘Naseptin’ nasal disinfectant cream.The incidence of staphylococcal sepsis in infants was much less than before the adoption of hexachlorophane prophylaxis. The sepsis rate was further reduced when ‘Naseptin’ was used in addition to hexachlorophane. Of the two prophylactic agents, hexachlorophane was the more convenient and probably the more effective. ‘Naseptin’ was difficult to employ correctly and unsuitable for routine use.The treatment of infants with disinfectants reduced nasal carriage markedly in infants and to a smaller extent in mothers. Both agents contributed to the reductions which persisted for some weeks after treatment ceased.Breast abscesses were almost entirely confined to mothers of infants who became nasal carriers by the second week of life.Staphylococcal colonization of infant's skin was greater when they wore impervious garments, probably because skin moisture increased.

1. Lysolecithin added in suitable doses to blood does not increase the red cell fragility in hypotonic saline, although the cells become spherical. The fragility of washed cells is slightly diminished by lysolecithin. The spherical cells produced by lysolecithin are essentially different from the spherocytes of congenital haemolytic anaemia. 2. After intravenous injection of lysolecithin into a rabbit, the fragility of the red cells remains raised for a much longer period than the spherical shape of the cells can be observed. 3. The effects of incubation of whole blood, and of plasma alone, on the morphology, volume, and fragility of the erythrocytes are contrasted. 4. The importance of the inhibiting action of plasma constituents on lysolecithin haemolysis is stressed. 5. The bearing of these experiments on some of the problems of haemolytic anaemia is discussed.

The antibiotic resistance of Staphylococcus aureus isolated in Bristol from primary skin sepsis and nasal carriers outside hospital was recorded between 1949 and 1969. The proportion of penicillinase-forming strains rose to about 60% but resistance to other antibiotics remained un-common except for a peak about 1957, due to the spread of multiresistant phage-type 80 staphylococci. Reasons are discussed for the failure of other multiresistant staphylococci to increase outside hospital.Recently isolated strains from inside and outside hospital were tested with sulphonamide and trimethoprim. All were sensitive to trimethoprim but 5% of non-hospital strains and 40% of hospital strains were resistant to sulphonamide. It is suggested that sulphonamide-resistant staphylococcal infections should not be treated with sulphonamide-trimethoprim mixtures because of the risk of breeding trimethoprim-resistant strains.

Plasma absorption studies were carried out on normal dogs and dogs with heart failure, with and without total lymph drainage from thoracic duct and right lymph ducts, after radioactive iodinated albumin (RISA) had been instilled into the lungs to explore a possible method for an indirect measurement of lung lymph flow. RISA entered plasma from the lungs mainly through the bloodstream. Its concentration in lung lymph correlated poorly with total lung lymph flow. More RISA entered the plasma than is normal in heart failure, implying an increased alveolar capillary permeability to protein in pulmonary oedema.

Images Figs. 1-3

SUMMARY One-hundred and one samples from a wide variety of sewers and water-drainage channels in Bristol, including some sewers that separately drained hospital and domestic premises, were examined for antibiotic-resistant coliform bacilli and for R factors. The antibiotic-sensitivity patterns of over 3000 coliform bacilli isolated were obtained and 1000 resistant strains were tested for R-factor transfer. Hospital sewage contained more coliform bacilli with much higher proportions of resistant bacteria, more R factors, and a greater proportion of R factors carrying multiple resistance, than sewage from domestic and other sources. Despite these findings, it was calculated that less than 5% of the R factors in the sewage output of the City of Bristol originate in hospitals. The normal, healthy population appears to be by far the greatest reservoir of R factors in the community.

Guidance by bacteriologists and changes in theatre and ward disciplines have greatly improved the results of urological surgery in recent years. The most noteworthy successes have been in treatment of chronic retention with renal failure, and in prevention of the bacteraemia which may occur following removal of the post-operative catheter or the passage of an instrument to dilate a stricture. It is hoped that safer urethral instrumentation may also reduce the incidence of chronic pyelonephritis.

Much cross-infection can be prevented by using chemical disinfectants to reduce the numbers of pathogens in sources such as superficial lesions and carrier sites, and by interrupting routes of spread. Examples are given to show the value of using disinfectants in the light of epidemiological knowledge.

The ground state transition probabilities for the 2 1 + states in 90 Zr and 60 Ni as determined by resonance fluorescence and reorientation effect methods are used as constraints to deduce transition densities from inelastic electron scattering data. The (e, e') cross sections for the 90 Zr, 2 1 + state at 2.186 MeV were measured at the Kelvin Laboratory, while for the 2 1 + state at 1.333 MeV in 60 Ni, the existing (e, e') data of Yale and Sendai were used. The discrepancy between the model independent (e, e') result of Yale for 90 Zr and the (γ, γ') measurement is explained. The importance of an accurate knowledge of the ground state charge distribution for analysis of (e, e') data is emphasized. For 90 Zr, the B (E2↑) is 674 ± 60 e 2 · fm 4 and R tr is 5.74 ± 0.11 fm. For the 1.333 MeV state in 60 Ni, these values are 918 ± 26 e 2 · fm 4 and 5.33 ± 0.03 fm respectively.

To discuss progress in the psychoneuroses without encroaching on the subjects of psychopathology and psychotherapy may appear like an attempt to play Hamlet without the Prince of Denmark. However, there remain certain aspects of aetiology, nosology, differential diagnosis and treatment which are not included in those subjects. It must clearly be understood that the ground covered by the following discussion is strictly limited owing to the above considerations. Thus, psycho-analytic work on the neuroses is to a great extent a matter of psychopathology and psychotherapy, and can therefore find little place in this chapter.

SUMMARY: The diffusion of streptomycin in agar gel seeded with staphylococci as in assay methods, results in a clearly defined zone of inhibition. The time required for this definition to develop is about 2 1/2 hr. at 37°, but varies greatly with temperature and is equal to the lag period plus approximately 4 times the generation time. After 4-5 generations the young colonies become much less susceptible and grow unimpeded by the rapidly increasing concentration of the antibiotic reaching them. Incubation at temperatures below 37°, although without significant effect on the minimum inhibitory concentration, results in larger inhibition zones because of increased generation times. In assays and sensitivity tests by diffusion methods, errors will occur if organisms under comparison do not multiply at the same rate.

Elastic electron scattering from 88 Sr, 89 Y, 90 Zr and 92 Mo has been measured in the momentum transfer range from 0.25 fm −1 to 1.15 fm −1 . The difference charge density distributions are compared with the predictions of the independent particle model. An estimate of the model-dependence of the difference density distribution is made. The data are found to be most sensitive to regions of the charge distribution from 3.5 fm to 4.5 fm.

SUMMARY The sources and routes of infection during continuous bladder drainage are discussed and illustrated. Twenty-nine male patients had continuous closed bladder drainage for periods of seven to seventy-seven days with an overall infection rate of 21 per cent. When accidental disruption of the closed circuit and repeated urethral instrumentation were avoided no patient became infected. Further improvements in the management of closed drainage are suggested. We wish to thank the consultant surgical staff of the United Bristol Hospitals, Southmead General Hospital and Frenchay Hospital, Bristol, for permission to investigate their patients. We are also grateful to Mr Ashton Miller for his help and advice during these studies.

Katz, A. M., Pearson, C. M., and Kennedy, J. J. (1963). Arthr. and Rheum., 6, 281. -(1965). Clin. Pharmacol. Ther., 6, 25. Kelly, M. (1964a). Med. J. Aust., 2, 541. (1964b). Lancet, 2, 474. Lansbury, J. (1958). Arthr. and Rheum., 1, 505. L?vgren, O., and Allander, E. (1964). Brit. med. J., 1, 118. Medical Research Council and Nuflield Foundation (1954). Ibid., 1, 1223. Mlchotte, L. J., and Wauters, M. (1964). Acta rheum, scand., 10, 273. Miehlke, K. (1965). Munch, med. Wschr., 107, 38. Norcross, B. M. (1963). Arthr. and Rheum., 6, 290. Percy, J. S., Stephenson, P., and Thompson, M. (1964). Ann. rheum. Dis., 23, 226. -and Thompson, P. (1963). 5th European Congress on Rheumatic Disease. Robecchi, A., Marrazzi, G., and Viara, M. (1964). Reumatismo, 16, 388. Robinson, R. G. (1965). Med. J. Aust., 1, 266. Ropes, M. W., Bennett, G. A., Cobb, S., Jacox, R., and Jessar, R. A. (1957). Ann. rheum. Dis., 16, 118. Rothermich, N. O. (1963). Arthr. and Rheum., 6, 295. (1964). Proceedings of 8th Congress of Japan Rheumatism Associa tion (Okayama), p. 159 Rubens-Duval, A., and Villiaumey, J (1964). Rev. Rhum., 31, 204. Smyth, C. J. (1965). Arthr. and Rheum., 8, 921. Amoroso, C, and Velayos, E. (1964). Ibid., 7, 345. and Godfrey, R. (1964). Ibid., 7, 345. Velayos, E. E., and Amoroso, C. (1963a). Ibid., 6, 299. -(1963b). Acta rheum, scand., 9, 306. Suzman, M. M. (1964). Rhumatologie, 16, 423. Thompson, M. (1964). Ibid.. 16, 439. and Percy, J. S. (1966). Brit. med. J., 1, 80. Viara, M., and Marrazzi, G. (1964). Rhumatologie, 16, 429. Vignau, A I., Correa, E. T., Guasch, J. L., Schuster, A. C, Patri, A. M., Vaisman, S. B., and Mortimer, E. A. (1965). Arthr. and Rheum., 8, 501. Wanka, J., Jones, L. I., Wood, P. H. N., and Dixon, A. St. J. (1964). Ann. rheum. Dis., 23, 218. Ward, J. R. (1964). Excerpta Medica International Congress, No. 82, edited by S. Garattini and M. N. G. Dukes, p. 353. Amsterdam.

Parameters for the ground state nuclear charge distributions of the isotopes 24Mg, 25Mg and 26Mg have been determined from elastic electron scattering in the momentum transfer range 0.20-1.15 fm-1. Calculations using a Nilsson model including configuration mixing up to 7 h(cross) omega show good agreement with experiment.

The first excited state of 26Mg was studied by inelastic electron scattering in the momentum transfer range 0.4 to 1.05 fm-1. The reduced transition probability and transition radius were measured to be 275+or-20e2 fm4 and 4.13+or-0.06 fm respectively. The reduced transition probability was found to be more accurate and of slightly smaller magnitude than existing experimental results. A Nilsson model form factor calculation was found to provide reasonable agreement with the experimental data.