Optimisation of a graded-index fibre over a wavelength range

The operation of graded-index fibres can be optimised in the neighbourhood of some wavelength whenever two dopants are available. Under the assumption that the index is a linear function of the dopant concentrations, a class of relations between dopants is found, which is related to that given by Olshansky.4 The case of a fibre doped with germanium and fluorine is treated.     

New method for precise characterisation of multimode optical fibres

It is shown experimentally that short samples (about 1 m) of multimode optical fibres can be characterised by measuring the times of flight of tubular modes. There is fair agreement between measured and calculated values.     

Stability analysis of adaptively controlled systems subject to bounded disturbances

An approach for studying stability of adaptively controlled systems subject to bounded disturbances with unknown statistics is given. A shorter proof of some results established for minimum phase systems is also given; new results are established for nonminimum phase systems. In each case, the uniform boundedness of all signals is proven under a condition that is discussed. Examples of adaptive schemes that can be treated with this approach are given.     

Large-bandwidth flat cylindrical array with circular polarisation and omnidirectional radiation

Experimental properties of a flat cylindrical array with circular polarisation and omnidirectional radiation are presented. The thickness of the array wrapped on a perfect conducting cylinder is 0.04?0. A bandwidth of 10% has been obtained. It is now possible to decrease the thickness by a factor 2 (i.e. to 0.02?0), when using a short-circuited elementary source instead of a flat folded dipole, and yet retain the same band-width.     

Pulse broadening in near-square-law graded-index fibres

A closed-form expression for pulse broadening in graded-index fibres that have small and circularly symmetric, but otherwise arbitrary, deviations from a square-law, and arbitrary dn/d?, is applied to germania-doped fibres. The range of validity of the theoretical expression is defined by comparison with the results of numerical integration.     

The underlying pathophysiology of ictal dystonia in temporal lobe epilepsy: an FDG-PET study

BACKGROUND: Unilateral dystonic posturing of limbs occurs frequently in medial temporal lobe epilepsy (MTLE) but its underlying anatomic basis is still unknown. OBJECTIVE: To investigate the pathophysiology of dystonic posturing, we examined the relation between the occurrence of dystonia and interictal cerebral metabolic abnormalities using fluorodeoxyglucose (FDG)-PET in MTLE patients. METHODS: Video recordings of 30 patients with documented MTLE were reviewed to assess the presence of ictal dystonic posturing. Interictal FDG-PET was performed in all patients. RESULTS: Eighteen patients exhibited dystonic posturing--contralateral to the seizure focus in 16 cases, bilateral in one, and ipsilateral in one. Dystonia was statistically associated with more severe hypometabolism in the striatal and in the orbitofrontal regions ipsilateral to the seizure focus. CONCLUSION: Hypometabolism observed in the striatal region of patients with ictal dystonic posturing suggests that the basal ganglia are involved in the generation of ictal dystonic posturing in MTLE.     

Clinical and psychological factors influencing the efficacy of botulinum toxin in the treatment of hemifacial spasm and blepharospasm

We analyzed the influence of clinical and psychological factors on the long-term efficacy of botulinum toxin A (BTX) injections in 45 patients with blepharospasm and 66 patients with hemifacial spasm. Injections efficacy (respectively 94.3% and 95.7%) and duration of relief (respectively 14.8 and 18.7 weeks) remained stable over seven successive injections. Clinical improvement was not influenced by patients' sex, age, or disease duration but by psychological background (p < 0.001). Patients who failed to respond after repetitive injections had lower inter-injections intervals (p < 0.05). This data shows: (1) the importance of psychological contexte in subjective evaluation of treatment efficacy with BTX, (2) emphasizes the necessity of avoiding close injections.     

Dorsalis pedis flap donor site: acceptable or not?

The dorsalis pedis flap has been used successfully for 20 years, both as a pedicled transfer for local foot reconstruction and as a free microvascular transfer. Proponents cite the reliable vascularity, versatility, ease of harvest, and thinness. Although significant donor-site morbidity has been recognized previously, published reports have inadequately documented the long-term effects of dorsalis pedis flap harvest. The purpose of the present study was to obtain long-term follow-up data regarding the donor site on a total of 10 male patients who underwent dorsalis pedis flap harvest during the period from 1982 to 1984. Standardized questionnaires and chart reviews were completed, and physical examinations and photographs of each patient were carried out when possible. Eight patients were reviewed, and seven of them were examined and photographed (mean follow-up 13 years). All patients had initially experienced delayed donor-site healing (mean 18 months; range 3 to 36 months). In addition, soft-tissue infections (five of eight cases), osteomyelitis (one of eight cases), wound breakdown (seven of eight cases), scarring and contracture (four of seven cases), pain or other uncomfortable sensations in the foot (six of seven cases), and requirement for reoperation (three of eight cases) were significant complications of the procedure. Most patients were able to attain their preoperative level of physical activity (five of eight cases). Although generally favorable reconstructive results were obtained in this series, the long-term follow-up of donor-site healing indicates that this flap should be used with caution. In particular, delayed donor-site healing, need for wound revision, and long-term and possibly permanent donor-site symptoms are common.     

First-order spectra with one binary predicate

The spectrum, Sp(), of a sentence is the set of cardinalities of finite structures which satisfy . We prove that any set of integers which is in Func₁^∞, i.e. in the class of spectra of first-order sentences of type containing only unary function symbols, is also in BIN¹, i.e. in the class of spectra of first-order sentences of type involving only a single binary relation.

We give similar results for generalized spectra and some corollaries: in particular, from the fact that the large complexity class _cNTIME_RAM(cn) is included in Func₁^∞ for unary languages (n denotes the input integer), we deduce that the set of primes and many “natural” sets belong to BIN¹.

We also give some consequences for the image of spectra under polynomials of .     

Mona, a novel hematopoietic-specific adaptor interacting with the macrophage colony-stimulating factor receptor, is implicated in monocyte/macrophage development

The production, survival and function of monocytes and macrophages are regulated by the macrophage colony-stimulating factor (M-CSF or CSF-1) through its tyrosine kinase receptor Fms. Binding of M-CSF results in Fms autophosphorylation on specific tyrosines that act as docking sites for intracellular signaling molecules containing SH2 domains. Using a yeast two-hybrid screen, we cloned a novel adaptor protein which we called 'Mona' for monocytic adaptor. Mona contains one SH2 domain and two SH3 domains related to the Grb2 adaptor. Accordingly, Mona interacts with activated Fms on phosphorylated Tyr697, which is also the Grb2-binding site. Furthermore, Mona contains a unique proline-rich region located between the SH2 domain and the C-terminal SH3 domain, and is apparently devoid of any catalytic domain. Mona expression is restricted to two hematopoietic tissues: the spleen and the peripheral blood mononuclear cells, and is induced rapidly during monocytic differentiation of the myeloid NFS-60 cell line in response to M-CSF. Strikingly, overexpression of Mona in bone marrow cells results in strong reduction of M-CSF-dependent macrophage production in vitro. Taken together, our results suggest an important role for Mona in the regulation of monocyte/macrophage development as controlled by M-CSF.