Sequence of the open reading frame of the FL01 gene from Saccharomyces cerevisiae

The cloned part of the flocculation gene FLO1 of Saccharomyces cerevisiae (Teunissen, A.W.R.H., van den Berg, J.A. and Steensma, H.Y. (1993). Physical localization of the flocculation gene FLO1 on chromosome I of Saccharomyces cerevisiae, Yeast, in press) has been sequenced. The sequence contains a large open reading frame of 2685 bp. The amino acid sequence of the putative protein reveals a serine- and threonine-rich C-terminus (46%), the presence of repeated sequences and a possible secretion signal at the N-terminus. Although the sequence is not complete (we assume the missing fragment consists of repeat units), these data strongly suggest that the protein is located in the cell wall, and thus may be directly involved in the flocculation process.     

Effect of surface recombination on the transient decay of excess carriers produced by short wavelength laser pulses

Effect of surface recombination on the transient decay of excess carriers injected very near to the surface region has been analysed for a semi-infinite semiconductor sample. The one dimensional continuity equation for the excess minority carriers has been solved analytically assuming that the surface recombination is important only on the front surface from which the excess carriers are injected. The decay of total excess carrier charge as a function of time is calculated for various values of the surface recombination velocities. It is found that values of S lower than 10³ cm/sec. have little effect on the decay of total excess charge and the decay is exponential. For values of S larger than 10⁴ cm/sec. the initial decay of excess charge is much faster and is dominated by the surface recombination. However, if one waits long enough for the excess carrier to diffuse into the semiconductor the decay becomes exponential when the excess charge decays to about 5% of its initial value. This exponential decay can be used to determine the excess carrier lifetime fairly accurately. A source of error in such experiments may arise from the heating of the silicon sample by the laser pulse. This effect, however is negligible for short duration pulses of low average power.     

Mixed land uses,land-use externalities,and residential property values: A reevaluation

Empirical evidence concerning the impact of neighborhood land-use externalities on residential property value is mixed. That is, no concensus has emerged in the literature as to whether locating non-residential land-use activities in residential neighborhoods can be expected to increase, decrease or leave unaltered surrounding property values. The purpose of this research was two-fold: 1) to construct a theoretical model of consumer behavior in which both the positive and negative effects of neighborhood land-use externalities are taken into account, and 2) to test this generalized model empirically, using hedonic pricing equations. The principal implication of the theoretical model is that the effect of non-residential activity on residential property values isa priori indeterminate, the outcome depending on the relative strength of the associated positive and negative external effects generated. The empirical test of the model was conducted for the city of Tucson, Arizona, where it is shown that over low ranges, increasing the amount of industrial, commercial, multifamily and public land-use activity in a neighborhood tended to increase surrounding residential property values. It is concluded that in locating future economic activity an optimal mix of landuse activities should be sought, not the regional separation of activities.     

Relations for hydration enthalpies of metalion-hydrates and stability constants of metal-dibenzoylmethane chelate complexes

Absolute hydration enthalpy (H) for cations relates well to lgK_Σ, the sum of the logarithms of the individual step chelation constants for metal-dibenzoylmethane complexes. The products $\text{d}{}^2$H and $\text{d}{}^2$lgK_Σ, where $\text{d}$ is the bond length, are essentially constant for a given cation valence (v) and increases as v². These relations fit a simple electrostatic model wherein the polarization of coordinating chelate or hydrate oxygen atoms is proportional to cation charge.     

Calculation of the amount of gas in the explosive region of a vapour cloud released in the atmosphere

Formulae were derived and calculations made for the amount of gas in the explosive region of a vapour cloud or plume. It appears that, for an instantaneous source, a large fraction of the total amount released (e.g. 50% for methane) can be in the explosive region, irrespective of source strength and meteorological conditions. On the other hand, for a continuous source, the amount in the explosive region is strongly dependent on source strength and meteorological conditions.To assist in the hazard analysis, a computer program was written to calculate the concentration as a function of time for a quasi-instantaneous spill of LNG on water.     

Invited peer review: The AABT experience.

In response to the growing need to provide the independent evaluation and examination of treatment programs, the Association for Advancement of Behavioral Therapy (AABT) formed the Professional Consultation and Peer Review Committee. The present study describes the peer review process in a hierarchical manner, beginning with the least demanding type of review or consultation and progressing to a full-scale evaluation. In the past 2 yrs, this committee has developed 6 types of review services that it offers free of charge to interested consumers and behavior therapists: individual case consultation between therapists, a compilation of guidelines for behavioral treatment programs, review of written materials of particular programs, on-site review of noncontroversial and controversial programs, and professional assistance in litigation involving determination of appropriate treatment. In all cases the committee promotes reliance on the empirical literature as the justification for treatment decisions and program operation. It is concluded that the review services are designed to protect individual clients and competent therapists and to assist in assuring appropriate treatment. (11 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Rain erosion damage in brittle materials

In order to understand the processes involved in the high-velocity rain erosion of brittle materials the impact damage produced in soda-lime-silica glass by single and multiple jet impact was studied. The damage was quantified by measuring the post-impact strength of specimens. It is shown that the impact damage depends on the impact velocity, the number of impacts and the specimen dimensions. A new analysis for calculating the velocity dependence of jet/drop impact damage in brittle materials is presented. The model is based on Hertzian contact analysis and dynamic fracture mechanics and takes into account the statistical nature of the flaws in the specimen. A good qualitative agreement with experimental results is obtained.     

Free-radical concentration in polymerizations

A method is described for deriving by digital computer a temperature program which, when applied to batch polymerization, will keep the supply of new free radicals constant throughout the main part of the reaction.