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A temperature-sensitive, cell division cycle mutant (cdc24–1) and karyogamy-deficient (kar1) mutant of Saccharomyces cerevisiae, both of which can produce binucleate or multinucleate cells, were used to study certain aspects of budding, after fluorescent staining for mannan, chitin, and nuclei (DNA). In most binucleate cells the two nuclei lay close together and divided into the same bud. In a few, however, the nuclei were far apart and one or two buds were formed, each proximal to a nucleus. The proximity of daughter nuclei in most blocked cdc24–1 cells suggests a role for the CDC24 gene product in spindle elongation. The relationship between the nuclei and the number and location of buds supports the theory of a preponderant role for the nucleus in budding. Although buds develop preferentially in regions of low chitin content in kar1 heterokaryons, the ability of cdc24–1 cells to bud even with a uniformly high content of chitin and mannan suggests a minor role for these cell wall constituents in determining the sites of bud emergence. The chitin ring is not needed for bud emergence but seems to play a role in normal bud development and in septum formation. Electron microscopy of cdc24–1 cells blocked (37 °C) for 8 h and released (23 °C) for 30 min showed morphologically normal spindle pole bodies, cytoplasmic microtubules, and intranuclear spindles. Although the chitin ring was absent, the ring of 10-nm filaments was present, consistent with its proposed role in bud emergence.

A new procedure for microelectrophoretic delivery of horseradish peroxidase (HRP) is described. A dilute solution (1.5–3% w/v) of fluorescein isothiocyanate-conjugated HRP is deposited according to a standard microelectrophoretic method and the tissue reacted according to a sensitive histochemical procedure. A major advantage of this method is the reduced secondary diffusion of the enzyme present at the injection site.

Afferents to the interpeduncular nucleus (IPN) of the rat were studied with the horseradish peroxidase (HRP) retrograde transport method. HRP was deposited microelectrophoretically in the IPN of adult rats. Major projections to the IPN originate in the medial habenular nucleus, the region surrounding the dorsal tegmental nucleus (accessory dorsal tegmental nucleus and the so-called dorsal tegmental nucleus pars lateralis), and the midbrain raphe (nucleus centralis superior and nucleus raphe dorsalis). Also, minor projections originate in the central gray and nucleus locus coeruleus. Our results indicate that the habenulointerpeduncular projection originates solely from the medial habenular nuclei and is topographically organized; medial regions of the medial habenular nuclei project to ventral portions of IPN and lateral regions project to the dorsal IPN.

An ozone system is to be used in a quarantine unit in which the bivalve Argopectin irradians irradians (Bay scallops) will be held at the Biological Research Station, Ellerslie, Prince Edward Island, Canada. A. irradians is not indigenous to Canada and, as such, all effluent must be disinfected to guard against the danger of an exotic algae and/or disease, possibly associated with the scallops, adversely affecting the native marine environment. A description of the system, techniques utilized, and test results obtained are presented along with suggested alterations to improve the system.

The proposed Hickory and Spring Creeks Flood Control and Recreation Project of the Illinois State Division of Water Resources and the Will County Forest Preserve District is desinged to provide flood control for Joliet, Illinos, and areas of the watershed to the east of the city and to provide open-space recreational land upstream from the Hickory Breek Dry Reservoir embankement. A viable forest ecosytem in the reservoir flood pool following construction is of major importance to the project. Factors of the environment influencing tree distribution and flood tolerance and a process for determining the best operational design to provide both flood control and the maintenance of a natural streamside forest ecosystem are described.

Şaşırtıcı sayıda çok, deneysel desen düzenleme türü vardır. Neyse ki en karmaşık deneysel desenler, görece daha az sayıda temel blok desenlerin bir bileşimini (kombinasyonunu) temsil etmektedir. Örneğin, en karmaşık desenler iki ya da daha fazla tam randomize, randomize blok veya Latin karesi desenlerinin birleştirilmesiyle oluşturulur. Tablo 1.4-1’de deney desenlerinin basit bir sınıflaması ana hatlarıyla verilmiştir. Daha karmaşık bir sınıflama sistemi Cox (1943); Doxtater, Tolman, Cormany, Bush ve Jensen (1942); ve Federcr (1955, 1956)’de vardır.

Measured excitation functions are compared to detailed evaporation calculations for the reactions $^{140}\mathrm{Ce}(^{16}\mathrm{O}, xn)^{156\ensuremath{-}x}\mathrm{Dy}$, $^{144}\mathrm{Nd}(^{12}\mathrm{C}, xn)^{156\ensuremath{-}x}\mathrm{Dy}$, $^{136}\mathrm{Ba}(^{20}\mathrm{Ne}, xn)^{156\ensuremath{-}x}\mathrm{Dy}$ ($x=5, 6, 7$), $^{154}\mathrm{Gd}(^{4}\mathrm{He}, xn)^{158\ensuremath{-}x}\mathrm{Dy}$ ($x=7, 8, 9$), and $^{181}\mathrm{Ta}(^{4}\mathrm{He}, xn)^{185\ensuremath{-}x}\mathrm{Re}(x=2, 3, 4)$. The agreement between theory and experiment is found to depend critically on the rate of photon emission within about 10 MeV of the yrast levels. For the first four systems above, good fits are obtained only when the $\ensuremath{\gamma}$-emission rate is strongly enhanced with respect to the rate indicated by the $\ensuremath{\gamma}$ width of neutron resonances. $\ensuremath{\gamma}$ enhancement by the following two methods leads to quite good fits to experiment: (1) a constant (independent of $J$) enhancement of a factor of 100 and (2) enhancement proportional to ($2J+1$). For the system $^{181}\mathrm{Ta}$ + $^{4}\mathrm{He}$ such pronounced enhancement does not seem to be required. These results are interpreted in terms of the structure of the $\ensuremath{\gamma}$-cascade band. At sufficiently high angular momenta, the $\ensuremath{\gamma}$-cascade band is predicted to give way to an $\ensuremath{\alpha}$ band. Possibilities are discussed for experimental verification of some of the theoretical predictions.