The bearable lightness of being

How are philosophical questions about what kinds of things there are to be understood and how are they to be answered? This paper defends broadly Fregean answers to these questions. Ontological categories-such as object, property, and relation-are explained in terms of a prior logical categorization of expressions, as singular terms, predicates of varying degree and level, etc. Questions about what kinds of object, property, etc., there are are, on this approach, reduce to questions about truth and logical form: for example, the question whether there are numbers is the question whether there are true atomic statements in which expressions function as singular terms which, if they have reference at all, stand for numbers, and the question whether there are properties of a given type is a question about whether there are meaningful predicates of an appropriate degree and level. This approach is defended against the objection that it must be wrong because makes what there depend on us or our language. Some problems confronting the Fregean approach-including Frege's notorious paradox of the concept horse-are addressed. It is argued that the approach results in a modest and sober deflationary understanding of ontological commitments

Studies on levels of luteinuzing hormone and prolactin In serum of cycling and anoestrous cows

Vlakke van luteiniserings hormoon (LH) in serum gedurende die estrus-siklus en die post partum periode is deur middel van radio immunologiese bepaling in 14 Brangus en 5 Fries koeie bepaal. Met die uitsondering van die periodes tydens die pre-ovulasie golf, het die basale vlakke van LH tussen 0,2 en 5,0 ng LH/ml serum gevarieer. Hierdie basale vlakke van LH, het net soveel tussen diere as binne diere of tussen die rasse gevarieer. Gedurende die pre-ovulasie golf het die LH vlakke verhoog tot tussen 8,0 en 60,0 ng LH/ml serum. In 16 van die 21 gevalle waar ovulasie gepaardgegaan het met estrus, het die verhoging in LH serum met die dag van estrus saamgeval. In 4 gevalle het die toe-name in LH 1,2 of 3 dae na estrus plaasgevind en in een geval 2 dae voor estrus. n Hoe voorkoms van ovulasie sonder estrus is gevind. Geen standhoudende veranderings in die prolaktien vlakke van die serum is in twee van die koeie gedurende die estrus siklus waargeneem nie.SUMMARYBlood levels of luteinizing hormone (LH) were measured, using a radioimmunossay, during the post-partum period in 14 Brangus and 5 Friesland cows. Except during pre-ovulatory surges, basal blood levels of LH ranged between 0,2 and 5,0 ng LH/ml serum. These basal levels of LH varied more between animale than either within animals or between breeds. During the pre-ovulatory surge. LH levels increased to between 8,0 and 60,0 ng LH/ml serum. In 16 of the 21 cases when ovulation was associated with oestrus, the LH surge was detected on the days of oestrus. In 4 instances, the LH surge was detected 1,2 or 3 days after oestrus and in one instance, 2 days before oestrus. A high incidence of ovulation without oestrus was noted. No consistent changes were detected in levels of prolactin in the serum of two of these cows during the oestrous cycle.

A Variational Principle for Eigenvalue Problems of Hamiltonian Systems

We consider the bifurcation problem $u'' + \lambda u = N(u)$ with two point boundary conditions where $N(u)$ is a general nonlinear term which may also depend on the eigenvalue $\lambda$. We give a variational characterization of the bifurcating branch $\lambda$ as a function of the amplitude of the solution. As an application we show how it can be used to obtain simple approximate closed formulae for the period of large amplitude oscillations.Comment: 10 pages Revtex, 2 figures include

Raman Studies Of Heavily Implanted, Dye-laser-annealed GaAs

Raman scattering is used to study the annealing behavior produced by 10 nsec, 565 nm dye laser pulses in high dose ion-implanted GaAs. Samples were prepared with Sn and Cd implantations of 2, 5, and 10 x 1015 cm2. The Raman spectra indicate that the threshold for epitaxial growth lies between 0.2 - 0.3 J cm2. Best carrier activation (∼ 2%), however, is achieved at ∼1.6 J cm2 for the Sn-implanted sample (n-type). For Cd implantation the electrical activation appears to be very high ({greater-than or approximate} 50%) for low pulse energies({less-than or approximate} 0.3 J cm2) but decreases for higher pulse energies. © 1985

Varieties of Limited Access Orders: The nexus between politics and economics in hybrid regimes

This article advances our understanding of differences in hybrid stability by going beyond existing regime typologies that separate the study of political institutions from the study of economic institutions. It combines the work of Douglass North, John Wallis, and Barry Weingast (NWW) on varieties of social orders with the literature on political and economic regime typologies and dynamics to understand hybrid regimes as Limited Access Orders (LAOs) that differ in the way dominant elites limit access to political and economic resources. Based on a measurement of political and economic access applied to seven post‐Soviet states, the article identifies four types of LAOs. Challenging NWW's claim, it shows that hybrid regimes can combine different degrees of political and economic access to sustain stability. Our typology allows to form theoretical expectations about the kinds of political and/or economic changes that will move different types of LAOs toward more openness or closure

The Effect of Diethylstilbestrol on the Digestibility of Dry Matter and Nitrogen and on Nitrogen Retention in Lambs

Although the usefulness of orally administered diethylstilbestrol (stilbestrol) in increasing weight gains and feed efficiency of fattening cattle has been established, little is known concerning the mechanism by which it exerts its beneficial effect. Two possible modes of action may exist. First, the stilbestrol may have some effect on the rumen microorganisms which might cause an increased digestion of feed in the rumen. Brooks et al. (1954) have shown that stilbestrol increased the digestibility of cellulose in the artificial rumen. They also obtained increased cellulose and protein digestion in sheep when stilbestrol was fed. However the levels fed the sheep were considerably above the mg. per lamb per day reported to be effective with lambs (Hale et al. 1955). Sykes et al. (1956) reported an increase in crude fiber digestibility and a decrease in protein digestibility with lactating cows when stilbestrol was fed. Digestibility of the dry matter of the ration tended to be improved but the differences were not statistically significant. Erwin et al. (1956) reported stilbestroI had no effect on digestibility of dry matter, crude fiber, crude protein or ether extract with steers. Secondly, the orally fed stilbestrol may exert some action on the metabolism of the animal\u27s tissue which is thought to occur when the stilbestrol is implanted (Clegg and Cole, 19 54). It has been shown that implanted stilbestrol increased nitrogen retention but had no effect on ration digestibility (Jordan 1953: Whitehair et al. 1953). Bell et al. (1955) found that orally fed stilbestrol increased nitrogen retention in lambs. Presumably this action is brought about by the absorbed stilbestrol acting similar to that on the implanted stilbestrol. The objectives of this report were to study the effects of different levels of stilbestrol upon the digestibility of dry matter and crude protein and on nitrogen retention with wether lambs

Control of unstable steady states by time-delayed feedback methods

We show that time-delayed feedback methods, which have successfully been used to control unstable periodic ortbits, provide a tool to stabilize unstable steady states. We present an analytical investigation of the feedback scheme using the Lambert function and discuss effects of both a low-pass filter included in the control loop and non-zero latency times associated with the generation and injection of the feedback signal.Comment: 8 pages, 11 figure

The Effect of Low Levels of Diethylstilbestrol and Plant Estrogens Upon Performance of Fattening Lambs

The excellent feeding properties of good quality legume hay and certain vegetable oil meals have long been recognized by the livestock producer. The observed feeding values of these feedstuffs cannot be attributed entirely to their classical nutrient compositions. It has been long suspected that they contain unidentified .factors that are stimulatory to growth