The effects of a single dose of 7,12-dimethylbenz(a)-anthracene on the epidermis and hair follicles of mice, with notes on concurrent changes in the ovaries and adrenals.

IN spite of the fact that skin was the first tissue in which chemical carcinogenesis was demonstrated, and that it is possible to study all stages of the carcinogenic process by inspection, there is still much controversy over the mechanism. One factor that has given rise to much debate is the part played by the hair follicles. In a previous paper (Orr, 1955), results were described which appeared to show that with a potent carcinogen the original hair follicles were completely destroyed, and replaced by differentiation from the regenerating epidermis, and that neither the original nor the neogenetic hair follicles gave rise to tumours. The earlier experiment was done with outbred albino mice. The present paper seeks to confirm and expand the results using pure-strain mice. During necropsies on the animals, changes were observed in the ovaries and adrenals, and brief notes on the nature of such changes have been appended to the main object of this communication. MATERIAL AND METHODS Three pure-line strains of mice were used: BALB/cf/Sp, March (MAf/Sp), and C3H/Sp. All mice were female; this was originally because of availability, but when during the experiment changes were observed in the ovaries, it was decided to continue with this sex. Twenty-eight mice of each strain were used. They were housed in metal boxes, up to three in a box, and fed on Purina Laboratory Chow, with water ad libiturn. They received one application (circa 0.15 ml.) of a 0.5 % solution in acetone of 7,12-dimethylbenz(a)anthracene (DMBA), on the interscapular skin. Half of them received this on the first day of the experiment, the remainder 4 days later, to obviate the necessity for killing animals at the week-ends. One animal o

My colleagues (do not) think the same: Middle managers’ shared and separate realities in strategy implementation

How does middle managers’ sensemaking of other middle managers’ attitudes to a new strategy affect strategy implementation? We explore this question using a qualitative-abductive approach. Our investigation of the implementation of a top-down strategy in the plant of a multinational German engineering company revealed that middle managers experiencing ambiguity make sense of other middle managers’ attitudes to the strategy in social interactions. Based on their understanding of their colleagues’ attitudes, middle managers construct shared and separate realities about the strategy to be implemented. While shared realities are subjectively experienced commonalities, separate realities are subjectively experienced differences from others’ attitudes to the strategy. In our case, middle managers’ shared realities were associated with inaction on strategy implementation, whereas middle managers’ separate realities were related to initial actions to implement the strategy. Our findings suggest that middle managers’ sensemaking of other middle managers’ attitudes to a new strategy can shape their strategy implementation behavior

Nonlinear optical response in doped conjugated polymers

Exciton effects on conjugated polymers are investigated in soliton lattice states. We use the Su-Schrieffer-Heeger model with long-range Coulomb interactions. The Hartree-Fock (HF) approximation and the single-excitation configuration- interaction (single-CI) method are used to obtain optical absorption spectra. The third-harmonic generation (THG) at off-resonant frequencies is calculated as functions of the soliton concentration and the chain length of the polymer. The magnitude of the THG at the 10 percent doping increases by the factor about 10^2 from that of the neutral system. This is owing to the accumulation of the oscillator strengths at the lowest exciton with increasing the soliton concentration. The increase by the order two is common for several choices of Coulomb interaction strengths.Comment: Accepted for publication in J. Phys.: Condens. Matte

Towards practice-based studies of HRM: an actor-network and communities of practice informed approach

HRM may have become co-terminus with the new managerialism in the rhetorical orthodoxies of the HRM textbooks and other platforms for its professional claims. However, we have detailed case-study data showing that HR practices can be much more complicated, nuanced and indeed resistive toward management within organizational settings. Our study is based on ethnographic research, informed by actor-network theory and community of practice theory conducted by one of the authors over an 18-month period. Using actor-network theory in a descriptive and critical way, we analyse practices of managerial resistance, enrolment and counter-enrolment through which an unofficial network of managers used a formal HRM practice to successfully counteract the official strategy of the firm, which was to close parts of a production site. As a consequence, this network of middle managers effectively changed top management strategy and did so through official HRM practices, coupled with other actor-network building processes, arguably for the ultimate benefit of the organization, though against the initial views of the top management. The research reported here, may be characterized as a situated study of HRM-in-practice and we draw conclusions which problematize the concept of HRM in contemporary management literature

An interacting segment model of molecular electric tensor properties: Application to dipole moments, polarizabilities, and hyperpolarizabilities for the halogenated methanes

A previously developed interacting segment model [ISM—see J. Chem. Phys. 67, 2109 (1977)] is applied to a full‐scale treatment of the electric dipole moments, isotropic and anisotropic polarizabilities, and hyperpolarizabilities of a series of 12 halogenated methane molecules CXnY4−n(X,Y = H,F,Cl; n = 0–4). The ISM scheme enables the molecular properties considered to be fitted in terms of a set of ’’bare’’ electric tensor parameters for each bond, which are modified (’’dressed’’) by intramolecular electrostatic interactions. The computed results of the ISM scheme, and of a corresponding interaction‐free bond additivity model, are discussed in relation to the following: choice of geometric and bond parameters, quality of fit to experimentally determined molecular and bond properties, and predictive potential and general physical validity of the model. It is concluded that the ISM approach represents a substantial improvement over simple bond additivity as a basis for understanding molecular electric tensor properties.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70686/2/JCPSA6-74-9-4858-1.pd

Making judgements about students making work : lecturers’ assessment practices in art and design.

This research study explores the assessment practices in two higher education art and design departments. The key aim of this research was to explore art and design studio assessment practices as lived by and experienced by art and design lecturers. This work draws on two bodies of pre existing research. Firstly this study adopted innovative methodological approaches that have been employed to good effect to explore assessment in text based subjects (think aloud) and moderation mark agreement (observation). Secondly the study builds on existing research into the assessment of creative practice. By applying thinking aloud methodologies into a creative practice assessment context the authors seek to illuminate the ‘in practice’ rather than espoused assessment approaches adopted. The analysis suggests that lecturers in the study employed three macro conceptions of quality to support the judgement process. These were; the demonstration of significant learning over time, the demonstration of effective studentship and the presentation of meaningful art/design work

Rossby wave propagation on potential vorticity fronts with finite width

The horizontal gradient of potential vorticity (PV) across the tropopause typically declines with lead time in global numerical weather forecasts and tends towards a steady value dependent on model resolution. This paper examines how spreading the tropopause PV contrast over a broader frontal zone affects the propagation of Rossby waves. The approach taken is to analyse Rossby waves on a PV front of finite width in a simple single-layer model. The dispersion relation for linear Rossby waves on a PV front of infinitesimal width is well known; here an approximate correction is derived for the case of a finite width front, valid in the limit that the front is narrow compared to the zonal wavelength. Broadening the front causes a decrease in both the jet speed and the ability of waves to propagate upstream. The contribution of these changes to Rossby wave phase speeds cancel at leading order. At second order the decrease in jet speed dominates, meaning phase speeds are slower on broader PV fronts. This asymptotic phase speed result is shown to hold for a wide class of single-layer dynamics with a varying range of PV inversion operators. The phase speed dependence on frontal width is verified by numerical simulations and also shown to be robust at finite wave amplitude, and estimates are made for the error in Rossby wave propagation speeds due to the PV gradient error present in numerical weather forecast models