Evidence of soft dipole resonance in

The first conclusive evidence of a dipole resonance in ^{11}Li having isoscalar character observed from inelastic scattering with a novel solid deuteron target is reported. The experiment was performed at the newly commissioned IRIS facility at TRIUMF. The results show a resonance peak at an excitation energy of 1.03±0.03 MeV with a width of 0.51±0.11 MeV (FWHM). The angular distribution is consistent with a dipole excitation in the distorted-wave Born approximation framework. The observed resonance energy together with shell model calculations show the first signature that the monopole tensor interaction is important in ^{11}Li. The first ab initio calculations in the coupled cluster framework are also presented.

A continuum description of the buckling of a line of spheres in a transverse harmonic confining potential.

A line of contacting hard spheres, placed in a transverse confining potential, buckles under compression or when tilted away from the horizontal, once a critical tilt angle is exceeded. This interesting nonlinear problem is enriched by the combined application of both compression and tilt. In a continuous formulation, the profile of transverse sphere displacement is well described by numerical solutions of a second-order differential equation (provided that buckling is not of large amplitude). Here we provide a detailed discussion of these solutions, which are approximated by analytic expressions in terms of Jacobi, Whittaker and Airy functions. The analysis in terms of Whittaker functions yields an exact result for the critical tilt for buckling without compression.

The expression and impact of antifungal grooming in ants.

Parasites can cause extensive damage to animal societies in which many related individuals frequently interact. In response, social animals have evolved diverse individual and collective defences. Here, we measured the expression and efficiency of self-grooming and allo-grooming when workers of the ant Formica selysi were contaminated with spores of the fungal entomopathogen Metarhizium anisopliae. The amount of self-grooming increased in the presence of fungal spores, which shows that the ants are able to detect the risk of infection. In contrast, the amount of allo-grooming did not depend on fungal contamination. Workers groomed all nestmate workers that were re-introduced into their groups. The amount of allo-grooming towards noncontaminated individuals was higher when the group had been previously exposed to the pathogen. Allo-grooming decreased the number of fungal spores on the surface of contaminated workers, but did not prevent infection in the conditions tested (high dose of spores and late allo-grooming). The rate of disease transmission to groomers and other nestmates was extremely low. The systematic allo-grooming of all individuals returning to the colony, be they contaminated or not, is probably a simple but robust prophylactic defence preventing the spread of fungal diseases in insect societies.

Influence of Siphonophore Behavior upon Their Natural Diets: Evidence for Aggressive Mimicry.

Collection by divers permitted determination of the natural diets of siphonophore species within II genera. Siphonophores that swim rapidly to spread their tentacles capture small prey, whereas those that swim very weakly capture much larger prey. Nematocyst batteries of two species of weak swimmers closely resemble copepods and fish larvae. Morphology, behavior, and diet suggest that these two species attract large prey by mimicking other zooplankton.

Population structure in a common Caribbean coral-reef fish: implications for larval dispersal and early life-history traits.

Genetic population structure throughout the Caribbean Basin for one of the most common and widespread reef fish species, the bicolour damselfish Stegastes partitus was examined using microsatellite DNA markers. Spatial autocorrelation analysis showed a significant positive correlation between genetic and geographic distance (isolation by distance) over distances <1000 km, suggesting that populations are connected genetically but probably not demographically, i.e. over shorter time scales. A difference in spatial patterns of populations in the eastern v. the western Caribbean also raises the probability of an important role for meso-scale oceanographic features and landscape complexity within the same species. A comparison of S. partitus population structure and life-history traits with those of two other species of Caribbean reef fish studied earlier showed the findings to be concordant with a common hypothesis that shorter pelagic larval dispersal periods are associated with smaller larval dispersal scales.

Airway cellularity, lipid laden macrophages and microbiology of gastric juice and airways in children with reflux oesophagitis.

BACKGROUND: Gastroesophageal reflux disease (GORD) can cause respiratory disease in children from recurrent aspiration of gastric contents. GORD can be defined in several ways and one of the most common method is presence of reflux oesophagitis. In children with GORD and respiratory disease, airway neutrophilia has been described. However, there are no prospective studies that have examined airway cellularity in children with GORD but without respiratory disease. The aims of the study were to compare (1) BAL cellularity and lipid laden macrophage index (LLMI) and, (2) microbiology of BAL and gastric juices of children with GORD (G+) to those without (G-). METHODS: In 150 children aged < 14-years, gastric aspirates and bronchoscopic airway lavage (BAL) were obtained during elective flexible upper endoscopy. GORD was defined as presence of reflux oesophagitis on distal oesophageal biopsies. RESULTS: BAL neutrophil% in G- group (n = 63) was marginally but significantly higher than that in the G+ group (n = 77), (median of 7.5 and 5 respectively, p = 0.002). Lipid laden macrophage index (LLMI), BAL percentages of lymphocyte, eosinophil and macrophage were similar between groups. Viral studies were negative in all, bacterial cultures positive in 20.7% of BALs and in 5.3% of gastric aspirates. BAL cultures did not reflect gastric aspirate cultures in all but one child. CONCLUSION: In children without respiratory disease, GORD defined by presence of reflux oesophagitis, is not associated with BAL cellular profile or LLMI abnormality. Abnormal microbiology of the airways, when present, is not related to reflux oesophagitis and does not reflect that of gastric juices.

Selective synthesis of the C3v isomer of C60h18.

[chemical structure: see text]. C60H18 has been produced by hydrogenation of C60 at 100 bar H2 pressure and 673 K for 10 h. We have investigated the crude material without any purification by use of 1H NMR, 13C NMR, and IR spectroscopy and Fourier transform ion cyclotron resonance mass spectrometry. We show that the crude material consists of 95% of the C3v isomer of C60H18.

Management of thyroid carcinoma with radioactive 131I.

PURPOSE: To evaluate the role of radioactive 131I in the management of patients with well differentiated carcinoma of the thyroid. METHODS AND MATERIALS: Between 1965 and 1995, a total of 117 patients with well-differentiated carcinoma of the thyroid underwent either lobectomy or thyroidectomy followed by 100-150 mCi of 131I. RESULTS: With a median follow-up of 8 years, only four patients (3%) developed a recurrence of their disease. The 5-year actuarial survival was 97% with a 10-year survival of 91%. There were no severe side effects noted after 131I therapy. CONCLUSIONS: Radioactive 131I is a safe and effective procedure for the majority of patients with well-differentiated thyroid carcinoma. We currently recommend that all patients undergo a subtotal or total thyroidectomy followed by 131I thyroid scanning approximately 4 weeks after surgery. If the thyroid scan shows no residual uptake and all disease is confined to the thyroid, we recommend following patients with annual thyroid scans and serum thyroglobulin levels. If there is any residual uptake detected in the neck or if the tumor extends beyond the thyroid, we recommend routine thyroid ablation of 100-150 mCi of radioactive 131I.

Purification of a 44 kilodalton protease which mediates the ecdysis of infective Haemonchus contortus larvae.

We have characterized and purified a parasite protease which mediates the ecdysis of Haemonchus contortus, and at least several other ruminant trichostrongyles. The protease, with an apparent approximate molecular weight of 44,000, is a zinc metalloprotein which hydrolyzes several large protein substrates in in vitro assays. In vivo and in biological assays on isolated second molt cuticles this protease hydrolyzes a specific circular region of the second stage cuticle which results in removal of a cuticular cap, providing a rapid and synchronous method for the escape of infective larvae during the transition from free-living to parasitic environments.

Bacterial corneal ulcers in cosmetic soft contact lens wearers.

Soft contact lenses provide a safe alternative to spectacles for more than 1 million patients. However, the hazard of bacterial corneal ulcers exists. This report describes five cosmetic soft contact lens wearers who developed bacterial corneal ulcers. In three cases, the resulting visual acuity was 6/120 or less. Possible sources of contamination are discussed, but in no case was it determined.

Hypertrophy with hyperpigmentation of the retinal pigment epithelium.

Fifty-two patients (one bilateral) exhibiting hypertrophy with hyperpigmentation of the retinal pigment epithelium (RPE) are described. Visual acuity was not affected, and the patients were asymptomatic. There was no correlation with systemic diseases, family history of eye disease, associated fundus lesions, anterior segment abnormalities, or intraocular pressure. Field defects were rarely demonstrated using standard clinical techniques. There were three characteristic locations and four characteristic pigmentary variations that occurred alone or in any combination. The lesions were gray, black, or brown. The clinical characteristics and histopathology suggest that hypertrophy with hyperpigmentation of the RPE and congenital grouped pigmentation are different expressions of a similar condition, with the former being focal and the latter multifocal.

Orbital myositis after upper respiratory tract infection.

Two cases of isolated unilateral extraocular muscle myositis after antecedent upper respiratory tract infections are reported. Pain, inflammation over the involved muscle, restricted motility, and an enlarged muscle on computerized axial tomography scan are the findings. This is differentiated from conjunctival inflammatory disease and neurologic disorders. The treatment is orally administered steroids.

Familial corneal hypesthesia.

A 4-year-old boy with severe, diffuse, asymptomatic, punctate, epithelial corneal erosions had bilateral sharply decreased corneal sensation with normal skin sensation in the distribution of the trigeminal nerves. Subsequent family studies disclosed five family members with similar corneal changes and decreased corneal sensation and no punctate erosions. None had decreased skin sensation in the distribution of the fifth cranial nerve. No environmental factors or evidence of local or systemic disease accounted for these findings.

Conjunctival lesions in periarteritis nodosa. A clinical and immunopathologic study.

Periarteritis nodosa is a disease with protean manifestations, yet there are few reports of ocular involvement. We treated a patient who was seen with conjunctival and anterior uveal involvement. The clinical histopathologic and immunopathologic characteristics are described. Immunopathologic studies are a useful adjunct in confirming the nature of this disorder.

Fleck corneal dystrophy.

Fourteen members of four families with fleck systrophy of the corneal stroma were examined and studied. Corneal and lens changes were noted in all patients. Corneal sensation was normal. Corneal biopsies were performed on two patients and a corneal button of a patient with fleck dystrophy and keratoconus was studied. Light and electron microscopy and histochemical studies showed this dystrophy to consist of abnormal keratocytes with variable numbers of membrane-limited intracytoplasmic vacuoles containing a granular to fibrogranular material that stains positively for mucopolysaccharide. This appears to be the first reported incidence of a dominantly inherited disorder of mucopolysaccharides affecting the eyes.

Conjunctival immunopathologic and ultrastructural alterations. Occurrence in Reiter's syndrome.

Immunoprotein deposition has been demonstrated in the synovium of patients with Reiter's syndrome. Because of this fact and the controversy regarding the nature and cause of the conjunctivitis in Reiter's syndrome, conjunctival biopsy specimens were taken from eight patients with classic Reiter's syndrome. These specimens were examined histopathologically, immunopathologically, and ultrastructurally. Our findings indicated that perivasculitis and vasculitis were present, preponderantly with elements of the cell mediated immune system. Genetically susceptible persons (namely, those with positive HLA-B27 antigen) exposed to an agent (Shigella or Chlamydia) may trigger an immune response in which vasculitis and perivasculitis plays a predominant role.

Corneal endothelial dystrophy. A study of 64 families.

A prospective study was undertaken during an 18-month period with 64 families who had endothelial dystrophy. Two hundred twenty-eight relatives were examined. Of those older than the age of 40, 38% were affected. Women were affected more severely and 2.5 times more frequently than men. The disease showed a strong familial tendency: there was one family in which three generations were affected and 16 families in which two generations were affected. There were four families that had members with edema in two generations. There was no association between edema in a parent and edema in a child. The proportion of relatives affected and the severity of involvement increased with age. Fifty-three probands and 18 relatives had endothelial dystrophy with edema (Fuchs' dystrophy). Of these 71, one had glaucoma.

The effect of unsuspected carotid-cavernous fistula in enucleation.

An 18-year-old man with an unsuspected carotid-cavernous fistula underwent enucleation as the result of a severe localized perforating ocular trauma. Potentially lethal bleeding occurred that was difficult to control. Auscultation of the orbit should be performed in all cases before eye enucleation to avoid the possibility of overlooking a carotid cavernous fistula.

Corneal ulcer caused by Pasteurella multocida.

A 44-year-old woman with Graves' disease and exophthalmos developed a severe corneal ulcer caused by Pasteurella multocida after being bumped on her right eye by her pet dog. The organism was transferred from the patient to an abraded rabbit cornea and produced a similiar corneal ulcer and hypopyon.

Corneal sensation in Adie's syndrome.

Using the Cochet-Bonnet esthesiometer, we evaluated the corneal sensation of 11 patients with unilateral Adie's tonic pupil. We eliminated six other patients with bilateral Adie's pupil or disease that lowered corneal sensation. An observed unfamiliar with each patient's condition tested 12 clock hour positions in the midperiphery in both eyes of all patients. We studied 30 normal subjects (60 eyes) in a similar fashion. Of those 11 patients with unilateral Adie's syndrome, ten had a regional decrease in corneal sensation. The 30 normal subjects examined did not exhibit any significant decrease in corneal sensation in any areas. Our study supports the concept that the lesion of Adie's tonic pupil is in the ciliary ganglion or short location where the innervation of the iris sphincter and corneal sensation are found together.