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Multiple sclerosis (MS) displays a month-of-birth effect, with an excess of individuals being born in the spring and a deficit in the winter. This effect was shown to be more pronounced in familial cases of MS. In the present study, we investigated whether this month-of-birth association has any relation to the principal MS susceptibility gene, HLA-DRB1.

Quadrature mirror filters are used throughout image and speech analysis; low crest factor arrays play an important role in many problems in antenna design and communication; uncertainty principle bounds limit resolution in time-frequency analysis and other areas; and complete orthonormal sequences are crucial in essentially all applications of mathematics to science and engineering. We present a single construction which unifies these four concepts.Copyright 1994, 1999 Academic Press

Chronic administration of benzodiazepine active at the tau-aminobutyric acidA receptor ("central" benzodiazepine sites) is associated with behavioral tolerance and receptor downregulation. Recent reports indicate possible interactions between central sites and benzodiazepines active at "peripheral-type" sites located primarily on non-neuronal cells. To evaluate these interactions during chronic administration, we treated mice with lorazepam for 1 to 14 days alone or in combination with the peripheral-type site ligand PK11195 [N-methyl-N-(methyl-1-propyl)chloro-2-phenyl-1-isoquinoline-3-carboxamid e]. Lorazepam was associated with tolerance at 7 days, but tolerance was not observed during concurrent administration of PK11195. Lorazepam was also associated with benzodiazepine receptor down-regulation in cortex and hippocampus at 7 days. With concurrent administration of PK11195, this effect remained in cortex but was absent in hippocampus. tau-Aminobutyric acid-dependent chloride uptake was reduced in both cortex and hippocampus with lorazepam, but not with concurrent lorazepam and PK11195. PK11195 administration alone did not affect behavior or neurochemical parameters, or did it alter brain lorazepam concentrations. These data indicate that concurrent PK11195 administration attenuates behavioral and neurochemical effects of chronic lorazepam administration.

A review of reported and new occurrences of 'Devonian' halysitids indicates that most are older than Devonian. Reports of Emsian halysitids from Chios are best attributed to errors in the compilation of Bassler (1950). The occurrences of halysitids in Quebec in strata considered Early Devonian provide the only plausible examples of the existence of this family in the Devonian. Thus, only Cystihalysites and Quepora appear to linger into the Devonian.Five Australian occurrences, yielding seven taxa, are described and interpreted as Silurian or older halysitids. All are from allochthonous material in the Early Devonian of New South Wales and include: Schedohalysites murramirra sp. nov., Halysites sussmilchi Etheridge and an indeterminate specimen from the Mullamuddy Formation near Mudgee; Schedohalysites sp. cf. S.? chillagoensis from the Sutchers Creek Formation, also near Mudgee; Quepora sp. indet. from the Jesse Limestone at Limekilns; cf. S. orthopteroides (Etheridge) from the Nubrigyn Formation near Stuart Town; and ? Halysites sp. indet. from the Sharpeningstone Conglomerate near Bowning.The type material of Schedohalysites ? chillagoensis (Etheridge) is redescribed and a lectotype selected.

Herpesvirus sylvilagus is a lymphotropic (type gamma) herpesvirus of cottontail rabbits (Sylvilagus floridanus). Analysis of virion DNA of herpesvirus sylvilagus has revealed that the genome consists of one stretch of about 120 kilobase pairs of internal, unique DNA flanked by a variable number of 553-base-pair tandem repeats. The G + C content of the repetitive DNA is extremely high (83%), as determined by sequencing. The organization of the herpesvirus sylvilagus genome is, therefore, similar to that of the primate lymphotropic viruses herpesvirus saimiri and herpesvirus ateles.

A procedure was developed for determining the relative levels of lactoperoxidase, leukocyte myeloperoxidase, and thiocyanate-sensitive peroxidase in human saliva. With this procedure, most of the peroxidase activity in whole saliva from normal (those without cancer) subjects was found to be associated with lactoperoxidase and thiocyanate-sensitive peroxidase, with only a minor contribution from leukocyte myeloperoxidase. In contrast, thiocyanate-sensitive peroxidase and leukocyte myeloperoxidase were the major peroxidase activities present in the residual salivary secretion obtainable from two xerostomic patients examined, and these enzymes were present at concentrations much higher than those normally occurring in human saliva. The occurrence of thiocyanate-sensitive peroxidase in saliva has not been previously reported and may represent either an additional peroxidase activity of saliva or a form of lactoperoxidase which is particularly sensitive to inhibition by thiocyanate.

An experimental determination was made of the type and magnitude of vibration in the simulated fuel rods of a heterogeneous nuclear reactor with water flowing parallel to the rod axes. Triangular lattices with equivalent hydraulic diameters of 0.0708, 0.198, and 0.470 ft were studied at a single rod length. The test rods employed had a range of natural frequencies of vibration in water of 5 to 25 cycles per sec. This range was obtained by using ½ and ⅝-in-diam rods made of brass or aluminum, by making some rods hollow and others solid, and by using fixed and pin-ended support conditions. The water velocity was varied from 6 to 21 fps, at room temperature. It was found that the vibration can be significant for reactor conditions. The rod vibration was observed to be self-excited, resulting in the rods vibrating at their natural frequencies independent of the water velocity. A theoretical study of the forces acting on the rods was made from which it appears that ten variables (of which six were varied in these tests) influence the amplitude of vibration of the rod. A correlation was derived and the resulting equations give a good fit with the test data.

Several letters to the editor are presented in response to articles in the previous issues including the cover story on actress Jeanne Moreau, the malicious things done by Brother El Hajj Malik El Shabazz who is known as Malcolm X of the Ku Klux Klan and the condemnation for the U.S. bombing of the Viet Cong forces by the Soviet Union.