Charge symmetry breaking in np-->dpi(0).

The forward-backward asymmetry in np-->dpi(0), which must be zero in the center-of-mass system if charge symmetry is respected, has been measured to be [17.2+/-8.0(stat)+/-5.5(syst)]x10(-4), at an incident neutron energy of 279.5 MeV. This observable is compared to recent chiral effective field theory calculations, with implications regarding the du quark mass difference.

Toxicity and behavioural effects of diet-borne alkaloids on larvae of the black blowfly, Phormia regina.

Larvae of the black blowfly, Phormia regina (Meigen) (Diptera: Calliphoridae) were exposed for 24 h to artificial diets that contained one of the following alkaloids: arecoline, caffeine, nicotine, quinine, sparteine or strychnine at either 1000 or 100 p.p.m. Each of the alkaloids caused reduced weight gain, relative to a control population in a no-choice bioassay and, with the exception of quinine, all alkaloids caused reduced larval weights in a choice bioassay. Larvae were unable to move away from diets containing arecoline (1000 and 100 p.p.m) and congregated away from diets containing 1000 p.p.m. quinine. Arecoline (1000 p.p.m) and both concentrations of nicotine caused significant mortality of larvae. Over a longer period (120 h), 10 and 1 p.p.m. nicotine resulted in significant numbers of larvae congregating away from a treated diet. Ten p.p.m. nicotine caused reduced weight gain over 120 h, although larvae provided with a choice were less affected. Exposure of larvae to dried residues of nicotine for 2 h did not affect subsequent development.

Can larvae of the pod-borer, Helicoverpa armigera (Lepidoptera: Noctuidae), select between wild and cultivated pigeonpea Cajanus sp. (Fabaceae)?

Experiments were conducted to observe the feeding and food selection-behaviour of different instars of the pod-borer Helicoverpa armigera (Hübner) in response to choices between the cultivated and a wild species of Cajanus. First and second instars fed upon a cultivated variety of Cajanus cajan in preference to a wild species, C. scarabaeoides and on flowers of C. cajan, rather than pods or leaves of C. cajan. First and second instars preferred pods of C. scarabaeoides with trichomes removed to pods with trichomes present. All instars fed upon pods of C. cajan rather than those of C. scarabaeoides. Solvent extraction of the pod surfaces affected the feeding of larvae, in some instances. They preferred the unextracted pods of C. cajan; the extracted pod of C. scarabaeoides (first and second instars) or the unextracted pod of C. scarabaeoides (fourth and fifth instars). Glass-fibre disc bioassays showed that the methanol, hexane and water extracts from the pod-surface of C. cajan stimulated the feeding of fifth instars. The experiments have shown that characteristics of C. cajan, such as either the compounds present or the type and distribution of trichomes on the plant surfaces, can determine the susceptibility of C. cajan to pod-borer larvae.

Parity violation in proton-proton scattering at 221 MeV.

The parity-violating longitudinal analyzing power, A(z), has been measured in pvectorp elastic scattering at an incident proton energy of 221 MeV. The result obtained is A(z) = [0.84+/-0.29(stat)+/-0.17(syst)]x10(-7). This experiment is unique in that it selects a single parity violating transition amplitude (3P2 - 1D2) and consequently directly constrains the weak meson-nucleon coupling constant h(pp)(rho). When this result is taken together with the existing pvectorp parity violation data, the weak meson-nucleon coupling constants h(pp)(rho) and h(pp)(omega) can, for the first time, both be determined.

Spontaneous degenerative spinal disease in the laboratory rabbit.

The spines of 35 rabbits (32 New Zealand white and 3 AC/J), ranging in age from 3 months to 8 1/2 years, were investigated systematically for spontaneous degenerative changes. Three types of lesion were observed. (1) The nucleus pulposus underwent chondroid metaplasia throughout the length of the vertebral column by the age of 2 years. (2) Hydroxyapatite deposition was found in the nucleus pulposus in 12 of 20 animals examined roentgenographically. The lesion occurred principally in the distal thoracic segments and was first observed in 3-month-old rabbits. (3) Spondylosis occurred in each of four macerated spines from animals greater than 24 months old. Portions of the spine spared by disc calcification were affected.

The role of epidural cortisone injection in the treatment of diskogenic low back pain.

Primary treatment by epidural injection of cortisone in patients suffering from characteristic diskogenic disease was helpful in 82% of patients. However, when given after three months of back pain, after previous laminectomies, and in patients actually suffering from an unstable spine which required fusion, epidural injections were of little value. No complications resulted from the injection and there was no compelling evidence to indicate that the placement of the needle by radiologic means is necessary. Because of these benefits and the fact that all of the patients were candidates for laminectomy, the use of this injection prior to surgery should be considered. The number of injections that may reasonably be given, the degree to which the patient should become asymptomatic, and the period of time during which relief continues remain to be clarified by a larger and more sustained study.

Anterior cervical fusion. A review of thirty-three patients with cervical disc degeneration.

Thirty-three patients who had undergone anterior cervical fusion for degenerative disc disease were reviewed to determine the efficacy of the procedure. Only patients who were available for examination and who had undergone operation at least one year previously were included in the review. Nearly all had had arm pain and three-quarters neck pain. Diminished neck movement and neurological abnormalities in the arms had been frequent findings. Diagnosis from the clinical features and plain radiographs is described. Myelography was not used routinely and discography was not used at all. Indications for operation and surgical technique are described. Results show that pain in the neck and arm was relieved in a high proportion of cases and that the neurological abnormalities often recovered. It is concluded that this operation is safe and has a definite place in the relief of pain from cervical disc degeneration resistant to conservative treatment.