Analytic Form of the Full Two-Loop Five-Gluon All-Plus Helicity Amplitude.

We compute the full-color two-loop five-gluon amplitude for the all-plus helicity configuration. In order to achieve this, we calculate the required master integrals for all permutations of the external legs, in the physical scattering region. We verify the expected divergence structure of the amplitude and extract the finite hard function. We further validate our result by checking the factorization properties in the collinear limit. Our result is fully analytic and valid in the physical scattering region. We express it in a compact form containing logarithms, dilogarithms, and rational functions.

All Master Integrals for Three-Jet Production at Next-to-Next-to-Leading Order.

We evaluate analytically all previously unknown nonplanar master integrals for massless five-particle scattering at two loops, using the differential equations method. A canonical form of the differential equations is obtained by identifying integrals with constant leading singularities, in D space-time dimensions. These integrals evaluate to Q-linear combinations of multiple polylogarithms of uniform weight at each order in the expansion in the dimensional regularization parameter and are in agreement with previous conjectures for nonplanar pentagon functions. Our results provide the complete set of two-loop Feynman integrals for any massless 2→3 scattering process, thereby opening up a new level of precision collider phenomenology.

Matter Dependence of the Four-Loop Cusp Anomalous Dimension.

We compute analytically the matter-dependent contributions to the quartic Casimir term of the four-loop lightlike cusp anomalous dimension in QCD, with n_{f} fermion and n_{s} scalar flavors. The result is extracted from the double pole of a scalar form factor. We adopt a new strategy for the choice of master integrals with simple analytic and infrared properties, which significantly simplifies our calculation. To this end, we first identify a set of integrals for which the integrands have a d log form, and are hence expected to have uniform transcendental weight. We then perform a systematic analysis of the soft and collinear regions of loop integration and build linear combinations of integrals with a simpler infrared pole structure. In this way, only integrals with ten or fewer propagators are needed for obtaining the cusp anomalous dimension. These integrals are then computed via the method of differential equations through the addition of an auxiliary scale. Combining our result with that of a parallel paper, we obtain the complete n_{f} dependence of the four-loop cusp anomalous dimension in QCD. Finally, using known numerical results for the gluonic contributions, we obtain an improved numerical prediction for the cusp anomalous dimension in N=4 super Yang-Mills theory.

Analytic Result for a Two-Loop Five-Particle Amplitude.

We compute the symbol of the full-color two-loop five-particle amplitude in N=4 super Yang-Mills theory, including all nonplanar subleading-color terms. The amplitude is written in terms of permutations of Parke-Taylor tree-level amplitudes and pure functions to all orders in the dimensional regularization parameter, in agreement with previous conjectures. The answer has the correct collinear limits and infrared factorization properties, allowing us to define a finite remainder function. We study the multi-Regge limit of the nonplanar terms, analyze its subleading power corrections, and analytically present the leading logarithmic terms.

[Abnormal central nervous conduction in long-term treatments with retinoids]. / Anomalies de la conduction nerveuse centrale lors des traitements au long cours par les rétinoïdes.

INTRODUCTION: Neurological manifestations are uncommon among the undesirable effects of systemic retinoid therapy. We observed a case of axial rigidity imputable to acitretine. Somesthesic evoked potentials were also altered. We therefore searched for such abnormal findings in patients given long-term systemic retinoid therapy. PATIENTS AND METHODS: A neurological exploration was performed in two groups of patients, G1 and G2, with psoriasis and no neurological complaint. The exploration included a physical examination, a study of the somesthesic evoked potentials of all 4 limbs and an electromyogram in case of abnormal findings. There were 8 patients (3 women, 5 men, mean age 56 years, age range 39-71) in G1 treated with systemic retinoids for a mean 140 months (80-185). Cumulative dose was 50 to 280 g with a daily dose of 0.2 to 0.6 mg/kg/day, i.e 20 to 50 mg/d of etretinate or acitretine. In G2, there were 5 subjects (mean age 42 years, range 21-52) with psoriasis (mean duration 20 years range 14-25) who had never been treated with systemic retinoids. RESULTS: Alterations in somesthesic evoked potentials were observed in 7 of the 8 patients in G1. Bilateral disturbances were seen in 6 cases, demonstrating abnormal lemniscal central nervous conduction in the dorsal and/or cervical level in 3 cases and the cervical level alone in 3 cases. There was one asymmetrical case involving the lumbar level on the right and the dorsal and/or cervical level on the right. Only one of the 5 controls in G2 had a minimal unilateral reduction in somesthesic evoked potentials involving the lower limb. Direct effect of systemic retinoids was retained in absence of any other cause due to metabolic, toxic or deficient disorders or spinal compression. CONCLUSION: Long-term use of systemic retinoids induces frequent latent neurological anomalies expressed as lemniscal central nervous conduction. It is hypothesized that pathogenesis involves changes in the lipid composition of the nervous membranes.

Familial motor neuron disease with Lewy body-like inclusions in the substantia nigra, the subthalamic nucleus, and the globus pallidus.

In a familial case of motor neuron disease (MND), 2 unusual features were noted in the necropsy. The first was a pallidoluysonigral degeneration, observed in only 4 other cases of MND and which was here asymptomatic. The second was the presence in degenerated spinal cord anterior horns and in degenerated basal ganglia of neuronal Lewy body-like inclusions stained by antibodies against ubiquitin.

[Back pain after epidural anesthesia]. / Douleurs rachidiennes après anesthésie péridurale.

A 24-year-old female patient underwent a minor orthopaedic procedure under epidural anaesthesia. She had a past history of lumbar backache. The epidural anaesthetic was carried out with the patient sitting. However, she had an acute vagal reaction, with loss of consciousness and forward headfall. Thirty-six hours later, the patient complained of severe pains diffusing all over her vertebral column, together with sciatica and paravertebral muscle contraction which did not respond to drug treatment. An epidural abscess or haematoma was ruled out. The pain finally disappeared after a few days of wearing a cervical collar, taking anti-inflammatory drugs, and a few vertebral manipulations. The back pain was probably due to a posterior articular joint syndrome, worsened by the forward headfall. In view of the past history, an epidural anaesthetic should probably have been best avoided.

Progress in continual eye pressure monitoring.

Observations of intraocular pressure (IOP) variations in response to CO2, adrenaline, speech and compression of the neck veins were documented by continual monitoring of IOP by radiotelemetry. Carbon dioxide increased IOP in the supine, but not in the erect, conscious subject. Adrenaline 2% caused a rapid short-lived painful increase in IOP, followed by a profound decrease. This was due to an increase in facility of outflow and was associated with paralysis of the sympathetic supply to the iris. Speech caused a small rise in IOP which was reversed by rest in silence. Compression of the neck veins caused a variable increase in IOP. These physiological variations in IOP may contribute to the errors of tonometry.

[Continuous ambulatory peritoneal dialysis in schizophrenia. Experimentation in 3 cases]. / La dialyse péritonéale continue ambulatoire chez les schizophrènes. Expérimentation dans trois cas.

The authors report their experience in using Continuous Ambulatory Peritoneal Dialysis (C.A.P.D.), in the treatment of chronic schizophrenia. This attempt refers to studies which confirm any role of endorphins in the origin of schizophrenia. Consecutively to american authors who found endorphins (molecular weight 3 300) in the dialysat of hemodialysed schizophrenics, they choose C.A.P.D. This continue technic of dialysis is more efficient than hemodialysis in removal of substances which molecular weight is between 1 500 and 5 000. This technic was used in 3 chronic schizophrenics: the disease has developed since 6 to 17 years and all the previous treatments failed. The duration of C.A.P.D. was 3 to 6 months. The only complication was one episode of inflammation of the peritoneum during 14 months of dialysis. Followed by the same staff with the AMDP 3 scale, the psychiatric evolution includes: --improvement and relapse in 2 patients (but we have to consider the difficulties of socioprofessional rehabilitation of these long term patients); --"clinical recovery" (17 months) in the third patient. The incidence of mothering and institutionalism is not negligible. Dosage of Met-enkephalin and beta-endorphin by radioimmunoassay in the drained dialysat did not show any difference between schizophrenics and the reference chronic renal patient. The results obtained with C.A.P.D. are not very satisfactory so far. But further research especially on the role of endorphins in schizophrenia and on their analysis technics in the body fluids perhaps will allow to treat schizophrenia again by dialysis.

[Effect of tiapride on the side effects of cerebrospinal fluid depletions in spinal puncture, pneumoencephalography and air myelography]. / Action du tiapride sur les eefets secondaires des soustractins de liquide céphalo-rachidien par ponction lombaire, encéphalographie et myélographie gazeuse.

The authors report their experience of the treatment post-cerebrospinal fluid loss syndrom, following subtraction by lumbar puncture, pneumoencephalography and air myelography. The study of 70 patients, divided in two equal groups, one receiving classic therapy, one receiving tiapride, a new molecule of original conception, lead to emphasize the interest of this drug. Tolerance in general is good, despite the administration of high doses and effects on the syndrom are positive and remarkable in preventive and curative treatment.