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110 records were found.

Type two cuts, bad cuts and very bad cuts are introduced by Keisler and Leth for studying the relationship between Loeb measure and U-topology of a hyperfinite time line in an $\omega_1$-saturated nonstandard universe. The questions concerning the existence of those cuts are asked there. In this paper we answer, fully or partially, some of those questions by showing that: (1) type two cuts exist in any nonstandard model of Peano Arithmetic, (2) the $\aleph_1$-isomorphism property implies that bad cuts exist, but no bad cuts are very bad.

## Compactness of Loeb Spaces

In this paper we show that the compactness of a Loeb space depends on its cardinality, the nonstandard universe it belongs to and the underlying model of set theory we live in. In section 1 we prove that Loeb spaces are compact under various assumptions, and in section 2 we prove that Loeb spaces are not compact under various other assumptions. The results in section 1 and section 2 give a quite complete answer to a question of D. Ross.

## Correlation of the earth's rotation rate and the secular change of the geomagnetic field

Power spectral density analysis using Burg's maximum entropy method was applied to the geomagnetic dipole field and its rate of change for the years 1901 to 1969. Both spectra indicate relative maxima at 0.015 cycles/year and its harmonics. These maxima correspond approximately to 66, 33, 22, 17, 13, 11, and 9-year spectral lines. The application of the same analysis techniques to the length-of-day (l.o.d) fluctuations for the period 1865 to 1961 reveal similar spectral characteristics. Although peaks were observed at higher harmonics of the fundamental frequency, the 22-year and 11-year lines are not attributed unambiguously to the solar magnetic cycle and the solar cycle. It is suggested that the similarity in the l.o.d fluctuations and the dipole field variations is related to the motion within the earth's fluid core during the past...

## Learning and learning capability in the Fordist and post-Fordist age: an integrative framework

In this paper we use the concept of 'learningcapability' to integrate several frameworks regarding the changing nature of industrial organization and international competition. In doing so, we emphasize the primacy of learning and learning capability in the post-Fordist world of international competition, with a focus on analyzing Fordist and post-Fordist forms of learning at various levels and their differing impact on the learning capability of firms in a regional context. First, we examine the organizational arrangements that promote individual and organizational learning within the firm, with special reference to the Japanese practices of lean and flexible production. Second, we introduce the concept of transactional learning to delineate various forms of Fordist and post-Fordist learning that occur in the marketplace. After reinte...

## Thermal Spin Valves

The ability of an insulating solid to conduct heat is rarely effected by the application of a magnetic field. We have found, however, that the low temperature heat conduction of some solids increases by more than a factor of two with the application of a modest magnetic field. The effect occurs in low-dimensional magnetically ordered materials when a small gap, \delta, in the acoustic magnon (spin wave) spectra is closed using a magnetic field H > \delta/g\mu_B. Since all magnetically ordered materials must have a gap in the magnon spectra for magnons with k = 0, this may be a very general effect. Extra heat is carried through the solid only when the magentic field exceeds the critical value (H > \delta/g\mu_B). At this critical field the tiny atomic magnets in the solid abruptly change the direction they point which results in more ...

## Linear Field Dependence of the Normal-State In-Plane Magnetoresistance of Sr2RuO4

Comment: 4 pages + 5 figures

## Spectral line similarity in the geomagnetic dipole field variations and length of day fluctuations

Power spectral density analysis using Burg's maximum entropy method (MEM) was applied to the geomagnetic dipole field and its rate of change for the years 1901-1969. Both spectra indicate relative maxima at 0.015 cycle/yr and its harmonics. These maxima correspond approximately to 66-, 33-, 22-, 17-, 13-, 11-, and 9-year spectral lines. The application of the same analysis techniques to the length of day (l.o.d.) fluctuations for the period 1865-1961 reveals similar spectral characteristics. The existence of the common spectral peaks with periods of 66 and 33 years in the l.o.d. fluctuations and the geomagnetic dipole field is clearly established. The existence of the higher harmonics is somewhat uncertain because of the line-splitting problem in the MEM spectral analysis. It is suggested that the spectral line similarity in the l.o.d....

## In vitro inhibitory activity of RepC/C*, the inactivated form of the pT181 plasmid initiation protein, RepC.

pT181 is a Staphylococcus aureus rolling circle plasmid that regulates its replication by controlling the synthesis of its dimeric initiator protein RepC/C and by inactivating the protein following its use in replication (A. Rasooly and R. P. Novick, Science 262:1048-1050, 1993). This inactivation consists of the addition of an oligonucleotide, representing several nucleotides immediately 3' to the initiation nick site, to the active site tyrosine of one of the two subunits, generating a heterodimer, RepC/C*. Previous results suggested that the inactive form was metabolically stable and was present at a much higher level than the active form (A. Rasooly and R. P. Novick, Science 262:1048-1050, 1993). In the present study we have measured total RepC antigen as a function of plasmid copy number and have analyzed the interaction of the tw...

## Observation of Bulk Superconductivity in NaxCoO2.yH2O and NaxCoO2.yD2O Powder and Single Crystals

Comment: 4 pages, 4 figures and 1 table