Effect of competitive cues on reproductive morphology and behavioral plasticity in male fruitflies

Phenotypic plasticity will be favored whenever there are significant fitness benefits of responding to environmental variation. The extent and nature of the plasticity that evolves depends on the rate of environmental fluctuations and the capacity to track and respond to that variability. Reproductive environments represent one arena in which changes can be rapid. The finding that males of many species show morphological, physiological, and behavioral plasticity in response to premating and postmating reproductive competition (RC) suggests that plasticity is broadly beneficial. The developmental environment is expected to accurately predict the average population level of RC but to be a relatively poor indicator of immediate RC at any particular mating. Therefore, we predict that manipulation of average RC during development should cause a response in plasticity “set” during development (e.g., size of adult reproductive structures), but not in flexible plasticity determined by the immediate adult environment (e.g., behavioral plasticity in mating duration). We tested this prediction in Drosophila melanogaster males by manipulating 2 independent cues of average RC during development: 1) larval density and 2) the presence or absence of adult males within larval culture vials. Consistent with the prediction, both manipulations resulted in the development of males with significantly larger adult accessory glands (although testis size decreased when males were added to culture vials). There was no effect on adult plasticity (mating duration, extended mating in response to rivals). The results suggest that males have evolved independent responses to long- and short-term variation in RC

Effect of competitive cues on reproductive morphology and behavioral plasticity in male fruitflies

Phenotypic plasticity will be favored whenever there are significant fitness benefits of responding to environmental variation. The extent and nature of the plasticity that evolves depends on the rate of environmental fluctuations and the capacity to track and respond to that variability. Reproductive environments represent one arena in which changes can be rapid. The finding that males of many species show morphological, physiological, and behavioral plasticity in response to premating and postmating reproductive competition (RC) suggests that plasticity is broadly beneficial. The developmental environment is expected to accurately predict the average population level of RC but to be a relatively poor indicator of immediate RC at any particular mating. Therefore, we predict that manipulation of average RC during development should cause a response in plasticity “set” during development (e.g., size of adult reproductive structures), but not in flexible plasticity determined by the immediate adult environment (e.g., behavioral plasticity in mating duration). We tested this prediction in Drosophila melanogaster males by manipulating 2 independent cues of average RC during development: 1) larval density and 2) the presence or absence of adult males within larval culture vials. Consistent with the prediction, both manipulations resulted in the development of males with significantly larger adult accessory glands (although testis size decreased when males were added to culture vials). There was no effect on adult plasticity (mating duration, extended mating in response to rivals). The results suggest that males have evolved independent responses to long- and short-term variation in RC

Engineers and management in manufacturing and construction.

There is a widespread view in the relevant academic literature that the UK's economic performance would be better if the situations of its engineers, engineering and manufacturing were more favourable. In particular the apparent dominance of accountants and financial expertise and the relative lack of influence of engineers and technical and productive expertise in manufacturing companies have been much discussed. As a presumed consequence of this, and despite a shortage of empirical evidence, engineers are apparently marginalised in managerial hierarchies, particularly in the most senior positions, and there is a subordination of technical to financial and other commercial priorities and objectives. The role of engineers in construction, however, has been virtually ignored despite the sector's economic importance and the relatively large numbers of engineers employed in it. The author and his supervisor conducted 25 interviews with representatives of the engineering and other main organizational professions, management institutes, employers' associations and a small number of academic and policy researchers. Their aim was to help identify the main issues which were relevant to UK engineers. From these interviews, and from reviewing the literature about engineers and management, the author decided upon the aims of the research. These were: to examine how engineers in manufacturing and construction feel about their influence and career prospects vis-ä-vis the members of the other professional groups with whom they work; to explore the perceptions of management-level people in industry about the managerial abilities of engineers and their colleagues; to investigate how engineers feel about the trade unions and professional associations which represent many of them; to examine the views of engineers about issues surrounding it engineering education and the importance which employers place on formal engineering qualifications; and to determine how engineers feel about the social place of their profession and about their levels of remuneration. Eighty-two interviews were conducted with engineers and their colleagues in three industrial sectors: mechanical and electrical engineering, chemicals, and construction. In manufacturing the main functional groups seemed to enjoy more constructive relationships than was apparently the case during the 1970s and 1980s. Although they appeared to form an influential group, the author found little evidence to support the notion that accountants dominate manufacturing companies, and they were generally considered both by themselves and by engineers and other colleagues to be performing a support function. Engineers appeared to enjoy the widest range of career opportunities of all the main management level groups, with the possible exception of chemists in chemicals. These opportunities included promotion to the boardroom. However some respondents felt that engineers needed to become rather less involved in the technical aspects of their work to advance their careers. In construction it was found that the main professional groups appeared to operate in varying degrees of mutual opposition. Their roles and influence depended to a large extent on the nature of the product and on the method of contracting chosen by clients. Architects in building and design engineers in civil engineering appeared to have lost their dominant positions in the management of projects. In both cases the main beneficiaries were contracting companies, which are staffed at management level mainly by engineers, and to a smaller extent quantity surveyors. 111 The author found no evidence to support the view that engineers are superior or inferior to other professional groups in terms of their `management' abilities, although the latter are clearly very difficult to measure. Only three of sixty-one engineer respondents were trade union members and most engineers appeared to believe that trade union membership was incompatible with their professional and/or managerial identities. About half of the engineers in the sample were members of professional engineering associations but this varied between sectors, as did the importance attached by respondents and their employers to chartered status. The engineer respondents tended to believe that their profession was poorly organised and ineffectual. Although employers appeared to rely heavily on formal qualifications to distinguish between different grades of technical staff, most respondents felt that engineering degrees needed to more practically oriented. The social standing of engineers and engineering was generally considered to be low. Many engineers believed that the general public neither understood nor appreciated fully what they did. However, engineers in the manufacturing companies in the study were generally satisfied with their levels of remuneration, although most respondents in construction felt that they were underpaid. The thesis concludes by arguing that when taken together with other evidence, particularly the many useful developments in education for management, the results suggest that the prospects for the UK economy might be considered to be improving, and certainly better than they were during the 1970s and 1980s

A Simple Design Algorithm For Synthesis Of Multilevel Combinational Networks

An algorithm is presented for the synthesis of combinational networks with a constrained arrangement of ANDS, ORS, NANDS, NORS, and inverters. The algorithm is easily presented to students in an introductory logic design course and has considerable application in modern practical logic design. Many texts available for a first course in logic design give very limited practical guidance for synthesis of networks under constraints outlined here. It is suggested that the algorithm presented here be furnished as supplementary material in the introductory course. Copyright © 1968 by The Institute of Electrical and Electronics Engineers, Inc

A Simplification Heuristic For Large Flow Tables

Flow tables specifying large asynchronous sequential circuits often contain more internal states than are required to specify desired circuit behavior. Known minimization techniques appear unsuited for reduction of such large (rows X columns \u3e 250) flow tables, because of excessive computation and intermediate data requirements for problems of this size. The algorithm described here is intended to rapidly produce a simplified-but in general non-minimal-flow table. It is most economical when applied to extremely large tables and was devised primarily for automated design applications. The procedure has been programmed in PL/1 and has been incorporated into an asynchronous sequential circuit design automation system developed at the University of Missouri-Rolla. Typical flow table simplification times obtained using the program are cited. In one test re-duction of a 217 row x 8 column table to 39x8 required about 2.6 minutes (the minimum table in this case was known to be 23x8)

Nutrient management on intensive dairy farms in the southwest of Ireland

End of Project ReportIntensive grass-based dairy farming relies on high inputs of nutrients that are now regulated under SI 378, 2006 (Good Agricultural Practice for Protection of Waters). This project studied nutrient management practices on twenty-one intensive dairy farms in the south-west of Ireland between 2003 and 2006. Mean stocking rate was 202 kg organic-N/ha deposited by grazing livestock. Overall fertiliser-N use on the farms decreased from 266 to 223 kg N/ha/yr during the study, with the rate of fertiliser-N in the first application each year decreasing from 49 to 33 kg N/ha, while the rate of fertiliser-N applied for first cut silage production also fell from 106 to 96 kg N/ha. These decreases were partly achieved by applying more slurry in springtime and by the introduction of white clover on five of the farms. While the limits on fertiliser-N use under SI 378 were exceeded on ten farms in 2003, the limits were exceeded on only two farms in 2006. Fertiliser-P usage declined from 12.0 to 10.2 kg P/ha/yr, and complied with the limits of SI 378 on thirteen of the farms in 2006. Mean Morgan’s extractable soil P concentration (STP) exceeded 10 mg/l on five farms, while the mean concentration exceeded 8 mg/l on ten farms. Phosphorus management, therefore, was close to that required by SI 378 on most farms. Slurry storage capacity met or exceeded the minimum requirements of SI 378 on eight farms; substantial investment in slurry storage facilities was necessary on thirteen farms. The mean N surplus on the farms declined from 277 to 232 kg N/ha/yr during the study due to a decline in total N input from 335 to 288 kg N/ha/yr over the same period. The mean efficiency of N-use increased from 17.9 to 20.2 %. The large variation in rates of fertiliser-N applied on farms with similar stocking rates suggests potential for further improvements in N use efficiency on some farms. Decreases in nutrient input levels can be partly attributed to increased farmer awareness, due to advice and record keeping from this study and the introduction of SI 378, and the increasing cost of nutrient inputs relative to output prices. In terms of fertiliser N and P use and soil P concentrations, complying with the limits in SI 378 does not require major changes in nutrient management practices on the majority of these intensive dairy farms

A State Assignment Procedure For Asynchronous Sequential Circuits

This paper presents a new procedure for constructing nonuniversal shared-row internal state assignments for asynchronous sequential circuits. The method consists basically of establishing an initial code with the minimum number of variables required to dis. © 1971, IEEE. All rights reserved