bluuebunny/crossref_metadata_2025 huggingface dataset:
A mixed‐integer linear programming decision model for aquaculture
Authors: Shaftel Timothy L. , Wilson Beverley M.
Published: May 2007

This paper presents a mathematical model for use in aquaculture, the rearing of aquatic animals in a controlled environment. The model addresses the real‐world strategic planning requirements of an emerging technology as well as the short‐ and long‐term production scheduling requirements of a mature aquaculture facility. A solution procedure for large‐scale problems is described and tested, and an illustrative application is presented.
CEO retention, firm performance and corporate governance
Authors: Fizel John L. , Louie Kenneth K. T.
Published: May 2007

This paper seeks to determine if CEO turnover is a function of firm performance, and therefore attempts to gauge the extent to which CEO interests are aligned with those of stockholders. The methodology in this paper focuses primarily on estimating the relationship between the probability of CEO exit and indices of firm performance and corporate governance structure. A major finding of the paper is that the accountability of CEOs to stockholders is significantly limited by CEO power, and CEO turnover is influenced more by internal governance structure than by firm profit or sales performance.
Strategic groups: Untested assertions and research proposals
Authors: Barney Jay B. , Hoskisson Robert E.
Published: May 2007

Strategic group theory has become a popular tool for analyzing competitive structure of industries. Indeed, testing for the existence of strategic groups, and the impact of strategic groups on a firm's performance, has become one of the dominant areas of empirical research in the strategic management literature. Unfortunately, the impact of this stream of research will be limited until some fundamental assertions in strategic groups theory are tested. Two of these assertions are: (1) that strategic groups exist and (2) that a firm's performance depends upon strategic group membership. These key assertions in strategic group theory remain untested for a variety of theoretical and empirical reasons. What needs to be done to test these assertions is discussed. Until these tests are complete, the contribution of the strategic groups concept will be unclear. If these tests do not build credibility for the concept of strategic groups, it may be necessary to abandon this concept and develop models where the strategically relevant attributes of firms are those that are idiosyncratic.
On the balancing of error rates for LP discriminant methods
Authors: Markowski Carol A.
Published: May 2007

This paper reports the results of an experimental comparison between a linear programming (LP) approach and Fisher's linear discriminant function (FLDF) for solving discriminant analysis problems. In particular, we examine the two‐group, two‐variable problem and the associated error rates for the two groups when each of the models is applied to various sets of simulated data. In contrast to previous research, we concentrate on individual error rates for the two groups, i.e. we count the number of group 1 values classified into group 2 and the number of group 2 values classified into group 1. The results indicate that not only is FLDF better at overall classification but it also provides a much better balance between error rates for the two groups.
A dynamic almost ideal demand system incorporating consumer expectations
Authors: Taube Paul M. , Macdonald Don N.
Published: May 2007

In this paper a theoretical framework is presented for the analysis of the effects of psychological, perceptual or expectational factors on household expenditure within a complete demand system. The model was estimated using the Consumer Sentiment Index, which represents an index of consumer perceptions of economic conditions. Evidence was found for significant expectational effects on five of nine expenditure categories—food at home, alcohol, housing, durables and other services. The direct expectation effects were found to be small in size. The results demonstrate the model's potential usefulness as a framework for modelling consumer behavioral responses to expectations and for evaluating the welfare implications of policy‐induced changes in expectations.
Matching the characteristics of a service to the preferences of customers
Authors: Reed G. V. , Binks M. R. , Ennew C. T.
Published: May 2007

The central task of any market‐oriented firm is to ensure that its product provides a mix of attributes that is consistent with the preferences of its customers. Attempts to measure the extent to which products meet consumer needs are often fraught with difficulties associated with eliciting and analysing the responses. We propose a simple index that can be applied to ordinal or cardinal data and will provide a convenient summary of the extent to which a product meets consumer expectations. The index, though simple, is shown to be robust, and is applied to the problem of analyzing the quality of banking services provided to small firms in the UK.
The coupon‐induced tax clientele effect in bond prices
Authors: Gay Gerald D, , Kim Seokchin
Published: May 2007

A pricing model for default‐free bonds under differentia! taxation of coupon income and capital gains is presented which explicitly considers coupon‐induced tax clienteles. Subsequent analysis provides indirect evidence in support of the existence of the coupon‐induced tax clientele effect, while direct evidence is provided by analyzing differences in marginal tax rates estimated across different coupon levels for sets of US Treasury bonds with the same maturity date. The results are also generally consistent with the traditional notion that marginal tax rates are inversely related to coupon levels.
Corporate takeovers, stockholder returns and executive rewards
Authors: Firth Michael
Published: May 2007

Various motives for making corporate acquisitions have been forwarded in the managerial economics literature. Two that have received a lot of attention are the maximization of stockholder wealth and the maximization of senior management's utility. These two alternative views can lead to different acquisition decisions. The paper examines the returns to senior management and the returns to stockholders following corporate takeovers in the United Kingdom. The evidence suggests that if shareholders profit from takeovers then so do the senior' management. Of more interest, however, is the finding that if acquisitions result in a reduction in stock market value for the acquiring firm, their senior management appear to gain. In particular, senior management remuneration increases substantially after an acquisition. This evidence is consistent with the maximization of senior management's utility being an important motive in many corporate‐acquisition decisions.
A systems approach to measuring retail structure in Germany and the Netherlands
Authors: Sybrandy A. , Tuninga R.
Published: May 2007

Institutional studies of retailing have primarily focused on the number and types of retailers to describe retail structure. This study provides an alternative approach to measuring retail structure based on general systems theory. The focus is on the examination of the work performed by retailers. Input‐output tables transformed into trade‐flow tables allow for such a functional approach to the measurement of retail activities in Germany and the Netherlands. This methodology allows for the examination of linkages of the retail sector with other parts of a national economy and provides an important tool for comparative marketing studies. The findings for Germany and the Netherlands are consistent with the marketing channels literature.
The economics of decision making in the new manufacturing firm
Authors: McNamara John R.
Published: May 2007

Decision making in a modern manufacturing firm producing a variety of products while meeting order deadlines appears at first to have little basis in the economic Theory of the Firm. It is shown that optimal budget allocations, the fractions of revenue expended on inputs, are likely to remain constant for a succession of orders for each of a family of products, thus simplifying the decision process. Well‐known heuristic decision rules may not only have a sound basis in economic theory but are evidently the best way to incorporate economic logic into a stream of fast‐moving decisions. The discussion is extended to an explanation of the economic value of decision making to the firm, and why this value is usually assumed to be zero in theory.
The concept of strategic groups: Theoretical construct or analytical convenience
Authors: Tang Ming‐Je , Thomas Howard
Published: May 2007

Despite the fact that a great deal of empirical research confirms the existence of strategic groups, not enough attention has been paid to their theoretical development. This paper links the theories of spatial competition and cognitive taxonomy to the very existence of strategic groups in a competitive environment. It is shown that the concept of strategic groups is not an analytical convenience but a theoretical construct.
A mechanism for reducing small‐business customer waiting‐line dissatisfaction
Authors: Martin G. E. , Grahn Joyce L. , Pankoff Lyn D. , Madeo Laurence A.
Published: May 2007

This paper presents a technique whereby a small business (i.e. a one‐cash register operation) can reduce customer waiting‐line time dissatisfaction in the purchase stage of the consumer decision process. When the queue length reaches or exceeds critical value N*, another employee is temporarily transferred to the role of ‘server assistant’ to increase the effective service rate; when the queue length eventually decreases to a second critical value N*, the server assistant returns to primary duties. An optimal customer‐reneging decision model is utilized to model the reneging character of the queue. Simulation experiments confirm key hypotheses concerning the behaviour of the queue and compare the effectiveness of a computed (N*, N*) policy with that of alternatives.
LIFO adoption and dividend payout
Authors: Kim Jeong Youn , Ettredge Michael
Published: May 2007

Adoption of the LIFO inventory costing method tends to decrease reported earnings but increases cash flows to adopting firms. This study examines the change in dividend payout ratios (cash dividends divided by earnings) accompanying LIFO adoption. The question addressed is whether adopting firms likely paid out incremental cash flows or retained them to the benefit of management. The evidence suggests that managers and directors adjusted payout ratios to partially offset the negative earnings effect of LIFO. The adjustments made were not sufficient in magnitude to achieve a neutral LIFO effect on dividend payout, and the net result was the retention of incremental cash flows generated by LIFO adoption.
Corporate growth, corporate strategy, and the choice of capital structure
Authors: Kracaw William A. , Lewellen Wilbur G. , Woo Carolyn Y.
Published: May 2007

The interaction between a firm's strategic decisions and its financial policies has become an increasingly frequent topic in the managerial economics literature. We examine here a dimension of that interaction that has not previously been addressed, and suggest a new framework for defining the manner in which choices of strategy and choices of capital structure might be jointly determined, in an environment where upward pressures on factor costs and product prices are the norm.
An analysis of foreign takeovers in the United States
Authors: Wayne M. Marr , Mohta Sanjeev , Spivey Michael F.
Published: May 2007

Using a sample of 96 US companies taken over by foreign companies during the period 1975‐87, we assess foreign takeovers in two stages: pre‐takeover and takeover. We find evidence that foreign firms target US firms whose operations are related to their own operations and that have low market‐to‐book ratios, suggesting foreign bidders acquire firms that provide a greater opportunity for market entry and synergistic gains. The synergistic gains appear to result from the foreign buyer using its own intangible assets (e.g. managerial skills) to improve the target. We also find that foreign takeover activity is aimed primarily at US industries that themselves make high levels of foreign direct investments, implying that the bidders use takeovers as a quick way to counteract rival firms' moves. We find evidence that foreign takeovers take place in relatively mature, low‐growth industries and that foreign targets are, on average, smaller than the non‐targets. The wealth effect on the announcement of a takeover is significantly higher for foreign takeovers than for takeovers by domestic firms. Also, we find that foreign bidders pay a slightly higher premium for targets whose operations are related to their own.
Managerial incentives and corporate control auctions
Authors: Banerjee Ajeyo , Owers James E.
Published: May 2007

An analysis of the sequence of bidding in corporate control contests involving white knights reveals a category of white knights termed as ‘delayed bid’ white knights who make their bid after two consecutive hostile bids. The ‘immediate bid’ white knights make their bid in relative haste after the first hostile bid. Overpayments by white knights are much larger for the ‘immediate bid’ white knights. An analysis of the respective compensation packages shows that the managers of the ‘immediate bid’ white knights have a lower proportion of their income linked to stock value (relative to their annual cash income) compared to ‘delayed bid’ white knights and hostile bidders.
Pricing currency options with scheduled and unscheduled announcement effects on volatility
Authors: Abraham Abraham , Taylor William M.
Published: May 2007

It is well documented that exchange rate volatility is time‐varying and that it can be affected by scheduled events such as money supply announcements and unscheduled ones such as spot market interventions and interest rate changes. This study provides a European event model (E model) for currency call options that explicitly addresses the volatility effects of these two classes of events. Managers who are concerned with hedging in an environment of changing volatility may find the E model useful. The E and modified Black‐Scholes (MBS) models have similar average errors in predicting option price changes across event windows and do better than a naive no‐change prediction. The E model tends to reduce the underpricing of convex, short‐term out‐of‐the‐money options and the mispricing of most classes of convex options.
The co‐operative nature of the firm: Narrative
Authors: Ichiishi Tatsuro
Published: May 2007

The theory of the firm views the firm as an organization characterized by (1) diversity of (and, most likely, conflict among) the interests of its members and (2) in spite of such diversity, the member's acceptance of a co‐ordinated choice of activities. A firm is a coalition formed when people play a co‐operative game, and this co‐operative game is the firm‐specific resource allocation mechanism. The theory includes: study of a descriptive general equilibrium model which embodies both the co‐operative game (for allocation of human resources, in particular for formation of firms) and the neoclassical market mechanism (for allocation of non‐human resources); its welfare implications; study of a normative mechanism to implement Pareto optimality in the presence of increasing returns to scale; and characterizations of the coalitionally stable hierarchical structures in a firm in a partial equilibrium setup.
The role of information in profit‐maximizing and labor‐managed duopoly models
Authors: Sakai Yasuhiro
Published: May 2007

This paper analyzes the welfare implications of acquiring information for profit‐maximizing and labor‐managed duopolies. We invent a unified method of exploring the role of information in a two‐person game under uncertainty on the basis of comparative static analysis, and then apply the method to both the PMF and the LMF. It is shown that whereas the LMF's behavior is analogous to that of the PMF twin in some circumstances, the former may be entirely different from the latter in others. Because a special status is accorded to labor as a variable factor of production, the informational analysis of the LM economy requires special care for both computations and interpretations.
Firm‐strategic behavior with industry‐demand externalities
Authors: Hula David G.
Published: May 2007

This paper investigates the effects of industry‐demand externalities on the firm's strategic decision making, with an industry‐demand externality being defined as a change in industry demand resulting from the efforts of a particular firm to develop, advertise or price a particular product. Profit‐maximization models of the firm's strategic behavior that incorporate industry‐demand externalities created by a particular firm and the competitive responses of its rivals reveal that the presence of such an externality serves as an incentive for the firm to engage in the form of strategic behavior that generates the externality.
Incentives and revenue sharing in college football: Spreading the wealth or giving away the game?
Authors: Brown Robert W.
Published: May 2007

The incentive mechanism literature is mostly theoretical since data limitations typically prohibit the testing of predictions. This paper offers an empirical study of the relationship between incentives and economic performance as applied to conference revenue sharing in college football. Revenue sharing acts as a disincentive to build a stronger team since the pecuniary rewards of team success are diminished if a team must share these rewards with conference opponents. This proposition is tested using data on team performance and revenue sharing rules in Division I‐A college football. The results confirm the main theoretical proposition – conferences which share more, tend to be weaker.
Asset specificity, capital intensity and capital structure: An empirical test
Authors: Harris Frederick H. Deb
Published: May 2007

Capital investment and capital financing decisions interact. To resolve current controversies in investment‐leverage‐growth relationships requires an integrated industrial organization/financial economics empirical model of profit margins, capital investment intensity, leverage and risk. Using cumulative future losses in discontinued operations to measure the asset specificity of the firm's investments, empiricai results support a complementary (positive) relationship between debt and investment, the debt financing of verifiable contemporaneous growth, equity financing of future growth and the debt financing of specific assets. This evidence rejects the transactions cost theory of capital structure in Fortune 500 firms.
Wealth effects of food and drug administration (FDA) decisions
Authors: Bosch Jean‐Claude , Lee Insup
Published: May 2007

Government regulations are an increasingly important component of the environment in which firms operate. Regulations may subject firms to large costs and possibly regulatory‐induced risks, both of which may have effects on stockholders' wealth. In this paper we investigate the valuation effects of Food and Drug Administration (FDA) product approvals, rejections and disciplinary decisions on the firms that operate in the food and drug industries. We find that FDA decisions have very large wealth effects. The large price changes associated with approval and rejection decisions suggest that a significant amount of uncertainty about FDA decisions is present almost up to the announcement day. These results are somewhat surprising given the lengthy period of time involved in developing and reviewing drugs and the continuous flow of information received by the market about their potential. We also find some evidence of information leaks preceding FDA announcements. With respect to disciplinary decisions, the evidence from the data suggests that stockholders experience large losses associated with FDA actions. Since these losses represent lost stream of future illegal income, it appears that ignoring FDA rules may be quite profitable for firms that are not caught.
Optimal decisions in foreign exchange bidding markets
Authors: Tenorio Rafael
Published: May 2007

I characterize optimal bidding decisions in bidding markets where each agent does not perceive she can significantly affect the market outcome. Using a foreign exchange bidding framework to provide a micro‐foundation for the shape of a bidder's payoff function, I show that (1) in a discriminatory auction a bidder bids for a price that equals the value of the marginal product of her bid quantity, and (2) in a competitive auction a bidder bids for a price that equals the value of the average product of her bid quantity. An example illustrates the comparative properties of these solutions.
Interpreting inefficiency ratings: An application of bank branch operating efficiencies
Authors: Haag Stephen E. , Jaska Patrick V.
Published: May 2007

Data Envelopment Analysis is an analytical tool for evaluating the relative technical efficiency of a set of organizations with the same multiple inputs and outputs. This paper examines the correct interpretation of inefficiency scores in the Additive model of Data Envelopment Analysis. A contrived numerical example is offered to demonstrate that certain computational statements appearing in recent literature are not entirely correct. As rectification, a region of stability is defined that identifies sufficient conditions for altering a technical inefficiency classification to that of technical efficiency. Finally, this region of stability technique is applied to bank branch operating efficiencies to demonstrate managerial interpretations and policy implications.
So, how long have you been in the market? The effect of the timing of observation on purchase
Authors: Putsis William P. , Srinivasan Narasimhan
Published: May 2007

Concentrating on the duration of the purchase deliberation process, we set out to address the following two questions: (1) Given that an individual is at a certain point in the deliberation process, what factors affect the likelihood of purchase? (2) Do the factors affecting purchase vary with the duration of the deliberation process? An empirical analysis of new car purchase survey data suggests that there are in fact significant differences at different stages of the deliberation process. Considerable differences are also found between those individuals who trade in a vehicle and those who do not.
Litigation costs and the underpricing of initial public offerings
Authors: Hensler Douglas A.
Published: May 2007

This paper examines a risk‐averse entrepreneur's motivation to underprice an initial public offering of equity where the entrepreneur faces the threat of litigation by outside investors. Outside investors have an incentive to seek compensation via tort law and the Securities Act of 1933 should the stock price fall subsequent to their purchase of the IPO. Potential litigation costs motivate the entrepreneur to underprice the IPO in a tradeoff between the litigation cost and the up‐front opportunity loss of underpricing. In a single‐period model, this paper formalizes the entrepreneur's pricing and retained ownership decisions resulting in ten testable hypotheses.
Are government or private enterprises more likely to engage in dumping? Some international evidence
Authors: Lott John R.
Published: May 2007

This paper provides the first systematic evidence comparing the incidence of below‐cost dumping among state and privately owned firms. Recent economic theory indicates that government enterprises, if motivated by goals such as output or revenue maximization rather than profit maximization, face higher returns to engaging in below‐cost pricing than private enterprises. International data from anti‐dumping investigations strongly confirm this prediction. Between 43% and 94% of initiated below‐cost dumping cases and between 54% and 100% of affirmative dumping decisions against exporting firms from nonmarket economies are attributable to those firms' publicly owned status. We are able to reject the hypotheses that this result is explained by political biases against nonmarket economies in anti‐dumping procedures or from possible political biases stemming from the industry composition of nonmarket exports. In fact in both cases, we find that the above results may understate the true effect of market organization on a country's propensity to engage in dumping.
The MNE investment location decision: Some empirical evidence
Authors: Mudambi Ram
Published: May 2007

Factors governing MNE investment are typically divided into three groups‐infrastructural variables, location‐specific risk factors and government policy variables. The first objective of this paper is to assess the influence of these factors on MNE location decisions. The second objective is to test whether government participation in location tournaments (whereby local governments offer incentives to MNEs to influence their location decisions) is worthwhile. Arthur (1986,1990) points out that such participation is worthwhile if government policy has irreversible effects that persist after policy is withdrawn. In the estimation of the model, neither risk nor infrastructural factors are found to have a significant effect on the MNE investment location decision. However, there seems to be some evidence indicating that past investment decisions tend to have irreversible effects. Thus, government participation in location tournaments may be worthwhile.
Merger analysis in the courts
Authors: Coate Malcolm B.
Published: May 2007

This paper presents an analysis of the merger decisions between 1982 and 1992. The survey of cases suggests that the plaintiffs win roughly half the time, a result which is invariant to the inferred political affiliation of the judge and within the time period under study. Further analysis suggests that barriers to entry and various competitive factors supplement the Herfindahl statistic in predicting the outcome of the case. Additional models link barrier and competitive conditions findings to exogenous factors such as the DOJ as a plaintiff and the filing for a preliminary injunction.
Video analysis of motor events in REM sleep behavior disorder
Authors: Frauscher Birgit , Gschliesser Viola , Brandauer Elisabeth , Ulmer Hanno , Peralta Cecilia M. , Müller Jörg , Poewe Werner , Högl Birgit
Published: May 2007

In REM sleep behavior disorder (RBD), several studies focused on electromyographic characterization of motor activity, whereas video analysis has remained more general. The aim of this study was to undertake a detailed and systematic video analysis. Nine polysomnographic records from 5 Parkinson patients with RBD were analyzed and compared with sex‐ and age‐matched controls. Each motor event in the video during REM sleep was classified according to duration, type of movement, and topographical distribution. In RBD, a mean of 54 ± 23.2 events/10 minutes of REM sleep (total 1392) were identified and visually analyzed. Seventy‐five percent of all motor events lasted <2 seconds. Of these events, 1,155 (83.0%) were classified as elementary, 188 (13.5%) as complex behaviors, 50 (3.6%) as violent, and 146 (10.5%) as vocalizations. In the control group, 3.6 ± 2.3 events/10 minutes (total 264) of predominantly elementary simple character (n = 240, 90.9%) were identified. Number and types of motor events differed significantly between patients and controls (P < 0.05). This study shows a very high number and great variety of motor events during REM sleep in symptomatic RBD. However, most motor events are minor, and violent episodes represent only a small fraction. © 2007 Movement Disorder Society
Characterization of the fraction components using 1D TOCSY and 1D ROESY experiments. Four new spirostane saponins from Agave brittoniana Trel. spp. Brachypus
Authors: Macías Francisco A. , Guerra José O. , Simonet Ana M. , Nogueiras Clara M.
Published: May 2007

A careful NMR analysis, especially 1D TOCSY and 1D ROESY, of two refined saponin fractions allowed us to determine the structures of four new saponins from a polar extract of the Agave brittoniana Trel. spp. Brachypus leaves. A full assignment of the 1H and 13C spectral data for these new saponins, agabrittonosides A–D (1–4), and one previously known saponin, karatavioside A (5) is reported. Their structures were established using a combination of 1D and 2D (1H, 1H‐COSY, TOCSY, ROESY, g‐HSQC, g‐HMBC and g‐HSQC‐TOCSY) NMR techniques and ESI‐MS. Moreover, the work represents a new approach to structural elucidation of saponins in refined fractions by NMR investigations. Copyright © 2007 John Wiley & Sons, Ltd.
Prehistoric dental disease and the dietary shift from cactus to cultigens in northwest Mexico
Authors: Watson J. T.
Published: May 2007

Differences in dental health of prehistoric human groups are commonly attributed to specific subsistence practices, whereby food foragers generally have a lower incidence of dental disease than agriculturalists. Dental health was assessed on a sample of 135 human skeletons from northwest Mexico that date to the Early Agricultural period (1600 BC–AD 200), which coincides with the initial introduction of domesticated cultigens into the region c. 2000 BC. High rates of dental caries (13.5%) and antemortem tooth loss (17.6%) encountered in these prehistoric forager‐farmers from the Sonoran Desert were determined to be the result of the consumption of highly cariogenic local wild resources such as cactus. These patterns mask the degree of reliance on agriculture in the area and highlight the importance of constructing local nutritional histories to better understand the diversity of human diets and their relationships to health and disease. Copyright © 2007 John Wiley & Sons, Ltd.
Long‐range orientation correlations and molecular alignment in sheared thermotropic copolyester. In situ light and X‐ray scattering
Authors: Romo‐Uribe Angel
Published: May 2007

Orientation correlations induced by shear flow and their relaxation were investigated using in situ small‐angle light scattering (SALS) in the thermotropic random copolyester of 60 mol% hydroxybenzoic acid (B) and 40 mol% ethylene terephthalate (ET). B‐ET displays a nematic polydomain texture, the SALS and wide‐angle X‐ray scattering (WAXS) patterns are amorphous and isotropic. Shear flow produced optical defect multiplication with the consequent reduction of the micro–domains size. However, SALS detected long‐range spatial correlations within the optically chaotic texture, the SALS patterns showed bimodal orientation of defects. After cessation of shear the orientation correlation rapidly relaxed back to a polydomain and the SALS pattern became again isotropic. Above a threshold shear rate of about $\dot {\gamma}_c \sim 2\; {\rm sec}^{-1}$ the SALS pattern showed unimodal orientation arising from line defects oriented nearly orthogonal to the velocity axis. Strikingly, the texture relaxation now showed the well known “banded texture”. The threshold shear rate coincided with a significant increase in the degree of molecular alignment as determined from in situ X‐ray scattering. This technique also showed that shear flow always oriented the molecular chains along the flow direction regardless of the shear rate. Copyright © 2007 John Wiley & Sons, Ltd.
A population study of neutering status as a risk factor for canine prostate cancer
Authors: Bryan Jeffrey N. , Keeler Matthew R. , Henry Carolyn J. , Bryan Margaret E. , Hahn Allen W. , Caldwell Charles W.
Published: May 2007

BACKGROUND

Prostate cancer has been reported to occur more commonly in neutered than intact male dogs in several case series. This study was undertaken to evaluate risk of prostate cancer in a large population database. The hypothesis was that castration is a risk factor for prostate cancer in male companion dogs.

METHODS

Data were derived from recorded visits to North American veterinary teaching hospitals. The Veterinary Medical Databases (VMDB) were queried to yield male dogs with urinary bladder transitional cell carcinoma (TCC), prostate adenocarcinoma (ACA), prostate TCC, prostate carcinoma (CA), and prostate tumors. A second query yielded all male dogs over the age of 4 years without a diagnosis of urinary tract cancer. These populations were compared to determine relative risks for developing each disease, singly and collectively, associated with neutering status. Odds ratios were calculated for breed as a risk factor.

RESULTS

Neutered males had a significantly increased risk for each form of cancer. Neutered males had an odds ratio of 3.56 (3.02–4.21) for urinary bladder TCC, 8.00 (5.60–11.42) for prostate TCC, 2.12 (1.80–2.49) for prostate adenocarcinoma, 3.86 (3.13–4.16) for prostate carcinoma, and 2.84 (2.57–3.14) for all prostate cancers. Relative risks were highly similar when cases were limited to those with a histologically confirmed diagnosis.

CONCLUSIONS

Breed predisposition suggests that genetic factors play a role in the development of prostate cancer. The risk associated with being neutered is highest for TCC, supporting previous work identifying the urothelium and ductular rather than acinar epithelium as the source of these tumors. Prostate 67: 1174–1181, 2007. © 2007 Wiley‐Liss, Inc.
R.B. Merrifield: European footnotes to his life and work
Authors: Jones John H.
Published: May 2007

Some reflections on the life and work of RB Merrifield in the European context are given. Copyright © 2007 European Peptide Society and John Wiley & Sons, Ltd.
Electron‐beam‐induced current study of grain boundaries in multicrystalline Si
Authors: Chen Jun , Sekiguchi Takashi , Yang Deren
Published: May 2007

Systematical studies on the intrinsic and extrinsic recombination activities of grain boundaries (GBs) in multicrystalline silicon (mc‐Si) were reported by using temperature‐dependent electron‐beam‐induced current (EBIC). EBIC results revealed that in the clean mc‐Si, all the GBs exhibited weak EBIC contrasts at 300 K, suggesting their recombination strengths were weak and the energy levels were associated with shallow levels. The effect of impurity contamination was also evaluated by employing different contamination levels of Fe. The EBIC contrasts of GBs were enhanced after Fe contamination and showed a strong dependence on both the GB character and contamination level. The impurity gettering abilities of GBs were as following, SA > R > high‐Σ > low‐Σ. SA GBs were found with the strongest impurity gettering ability and tended to be the most detrimental GBs. Finally, the effect of H‐passivation on different GBs with or without contamination was evaluated. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Oxygen gettering at defects introduced by plastic deformation in silicon
Authors: Yarykin N. , Hieckmann E. , Vdovin V. I.
Published: May 2007

Decay of the supersaturated oxygen solid solution during annealing at 500–800 °C is studied in plastically deformed silicon crystals. The plastic deformation up to 4–5% is found to significantly increase the rate of the decay. In the samples deformed at 700 °C the decay is governed by the oxygen diffusion not to dislocations but to other defects created during deformation. These defects are recovered due to the short annealing at 1150 °C. In the annealed samples the decay of oxygen solution is determined by the oxygen diffusion to dislocations. In both cases the activation energy of oxygen transport in the temperature range (500–700) °C is about 1.5 eV. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electrical properties of dislocation trails in n‐Si
Authors: Feklisova O. V. , Yakimov E. B.
Published: May 2007

The deep level centers introduced by plastic deformation at 620 °C in n‐type silicon are quantitatively studied by the electron beam induced current and deep level transient spectroscopy techniques. It is shown that the most efficient deformation‐induced electrically active defects in Si are located in the dislocation trails. The deep level spectrum associated with these defects is obtained. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Ninth‐grade student engagement in teacher‐centered and student‐centered technology‐enhanced learning environments
Authors: Wu Hsin‐Kai , Huang Ya‐Ling
Published: May 2007

Engagement has been viewed as an important construct to understand students' learning performances in classroom settings. Taking an interactive perspective, the study investigates ninth graders' cognitive, emotional, and behavioral engagement in teacher‐centered (TC) and student‐centered (SC) technology‐enhanced classrooms. 54 students from two science classes in Taiwan participated in this study. Multiple sources of data were collected during a 3‐week instructional unit. The statistical results showed that although students in the SC class reported having significantly higher emotional engagement, the emotional engagement level had no impact on students' learning achievement. Analyses of qualitative data showed that students in both classes spent a majority of class time on cognitive involvement in learning activities, but there were qualitative differences in cognitive and behavioral engagement between the two classes. One type of activities that did not occur in the TC class was making reflections in which students in the SC class self‐assessed what they did. In addition, the SC class usually interacted through group discussions provoked by the simulations, whereas the TC class frequently interacted through initiation–response–evaluation sequences and engaged in student‐initiated discussions. The findings suggest that both instructional approaches promoted students' conceptual understanding and provided students with different opportunities to engage in science learning. © 2007 Wiley Periodicals, Inc.Sci Ed91:727–749, 2007
The spectrum of stress
Authors: Hordern Anthony
Published: May 2007

The spectrum of stress, inter alia, comprises: the concept of stress — originated in its present form by Hans Selye; technosocial contributory factors — urbanization, oral contraception, television, microelectronics; individual vulnerability — overall effects, age and personality factors, common sources; reactions and responses — getting emotional support, coping behaviour, the development of illness(es); and depressive illness as a stress paradigm — its nature, management and growing importance in the world today.
Psychosocial factors in breast cancer
Authors: Cheang A. , Cooper C. L.
Published: May 2007

One hundred and twenty‐one patients who were admitted for breast biopsy were interviewed on the day before the operation. They were asked to recall all stressful life events which had occurred during the two years that preceded the onset of cancer. An appropriate control group of 42 healthy patients from a well woman clinic were also interviewed. All patients also completed a self‐rating questionnaire. Scaling of life events was done by another group of hospital inpatients.

The results showed that cancer patients experienced significantly more stressful life events in the two years that preceded the onset of cancer than the non‐cancer and well woman patients. Cancer and non‐cancer patients experienced events with medium and high stress factors, while the well woman patients experienced events with low and medium stress factors. The main difference in personality was that cancer patients tended to ‘conceal their feelings’, while the non‐cancer and well woman patients were more ‘expressive of their feelings’. The differences in personality profile and experience of stressful life events between the three groups of patients could be explained in terms of coping strategies and locus of control. The implications of this study are also discussed.
Antidepressants, stress and cardiotoxicity
Authors: Davidson W. J.
Published: May 2007

Various types of cardiomyopathies have been induced in rats, which were then subjected to a standard noise stress. This resulted in immediate death due to ventricular fibrillation in some 2 per cent of the animals. Pretreatment with tricyclic antidepressants increased this mortality dramatically to 70–90 per cent, although concomitant administration of propranolol and various anxiolytic drugs protected against this effect to varying degrees.

Further experiments, using cold and exercise stressors, produced similar results, although the noise stress was by far the most lethal. Propranolol protected the animals against the effects of cold and exercise stressors but diazepam did not.

Experiments with the second generation antidepressants, trazadone and nomifensine, were completely negative and it would appear that, in the context of this animal model, these drugs possess no cardiotoxic effects.

There would seem to be a direct parallel between these animal experiments and tricyclic cardiotoxicity in man, the depressive illness itself or its precipitating causes constituting the stress factor. Our results suggest that the second generation antidepressants would appear to be safer from this point of view.
The interactive patterns of occupations and workers in predicting excessive occupational stress
Authors: McKenna Jack F. , Scholl Richard W.
Published: May 2007

A rural hospital was selected for this research. Respondents (n = 330) completed questionnaires which collected biographical/occupational characteristics and perceptions regarding five dimensions of occupational stress. A two‐way ANOVA procedure indicated that substantial interactive effects existed between a number of respondent characteristics and their departmental affiliation with regard to predicting elevated stress perceptions in four of the five categories.
Sleep and coronary heart disease
Authors: Partinen Markku
Published: May 2007

The relations of sleep and cardiovascular functions are not clear. Cardiac output tends to decrease during sleep in general, but during REM sleep arterial pressure and heart and respiratory rates vary. Occasionally systolic pressure may exceed daytime values. In general, the reduced sympathetic activity during sleep decreases the vulnerability of the heart to ventricular premature beats and tachycardias. Bradyarrhythmias and conduction blocks, on the other hand, are fairly common, especially during REM sleep. Usually these arrhythmias are not dangerous, and there is no risk in dreaming a lot. However, in some pathological conditions, eg among patients with severe coronary heart disease, an imbalance of vagal and sympathetic activity might contribute to fatal arrhythmias. In practice, this means that in such conditions it might be wise to avoid REM‐rebounds with nightmares, eg after sudden cessation of use of sedative drugs or alcohol. Sleep hypoxaemia due to apnoeas, and secondary cardiac arrhythmias, might explain some cases of nocturnal sudden deaths. Habitually snoring obese men have an elevated risk of obstructive sleep apnoeas. It remains to be studied whether habitual snorers and patients with sleep apnoeas have a higher risk of myocardial infarction than occasional snorers.
Effects of noise on health and well‐being
Authors: Rehm S. , Gros E. , Jansen G.
Published: May 2007

Noise‐induced hearing loss due to intense and long‐term noise exposure is no longer disputed since the etiology is well defined. However, the influence of noise on the vegetative functions is not so clear. In addition to existing investigations on vegetative functional disturbances, the role of noise as a risk factor has to be determined and its effects have to be quantified. The significance of noise‐induced sleep disturbances in relation to health and well‐being, is also controversial. The hypothesized causal connection between acoustical stimulation and the occurrence of disorders, includes primary‐effects (e.g. awakenings) and after‐effects (e.g. changes in mood or performance). To date, it has not been feasible to determine late after‐effects, such as health disorders. The most often reported sociopsychological effect of noise is general annoyance, whereby annoyance is defined as disturbance of communication, rest, recreation or concentration. Some results indicate a higher sensitivity of critical groups (e.g. old people, the sick, children, pregnant women).
Stress and alcohol
Authors: Stockwell Tim
Published: May 2007

Using alcohol to cope with stress is a common reason for drinking, and alcohol has the pharmacological capability of reducing states of tension when used in moderate doses. This effect may, however, be dependent to some extent on the drinker's faith as to its anxiolytic powers. On the other hand, regular and heavy consumption of alcohol is likely to increase the risk of various mental health problems and enhance any states of ‘tension’. These conclusions highlight the importance of screening for alcohol abuse when attempting to intervene in any psychological or emotional problems.
Cancer mortality following widow(ER)hood: Some further results from the Office of Population Censuses and Surveys Longitudinal Study
Authors: Jones D. R. , Goldblatt P. O.
Published: May 2007

Many studies have suggested that following the experience of ‘stressful’ life events the risks of myocardial infarction, accidents and perhaps other diseases including cancer are elevated. In the OPCS Longitudinal Study (LS) routinely collected data on deaths, and deaths of a spouse occurring in a 1 per cent sample of the population of England and Wales in the period 1971‐81, are linked together and with 1971 census records of sample members. The timing and patterns of death following the potentially very stressful event of conjugal bereavement may thus be analysed.

Overall the mortality in widowers, but not widows, was about 10 per cent in excess of that in all members of the LS sample for most major cause of death groups. As in many earlier studies, some increases in death rates shortly after widow(er)hood are observed. Unusually, for deaths from all causes these increases are more marked in widows than in widowers, with, for example, a twofold increase in mortality from all causes in the first month after widowhood. However, no peak of postbereavement mortality from malignant diseases is clearly established in either sex.

Although the study is large, with a well‐chosen control group, only a limited characterization of study members from data collected in the census is possible. In particular no measures of personality or behaviour are available. Gradients in postbereavement mortality similar to those in general mortality were found with several measures of socioeconomic status, including social class. Investigation of potential effects of social or familial support, as measured by household structure and numbers of children, led to equivocal results.

The observed patterns, although consistent with an early effect of a stressful life event, do not strongly suggest that stress following bereavement leads to an excess of cancer mortality. The limited follow‐up of the study cohort since widowhood must, however, be kept in mind.
Anxiety and first‐time mothers
Authors: Barnett Bryanne E. W.
Published: May 2007

Whereas the child's need for mothering is absolute, the need for an adult woman to mother is relative. During pregnancy and subsequent child development, the mother unconsciously relives her own infantile and childhood experiences. Psychiatric disturbance is common in pregnancy and anxiety may be normal or pathological. ‘State’ or ‘trait’ anxiety need to be differentiated in order to consider treatment interventions. High anxiety levels may exert a number of adverse effects on mother and child alike. Adequate social support is important and intervention should be considered on humane grounds at the very least.
Taking the anxiety out of AIDS
Authors: Miller David
Published: May 2007

AIDS‐generated anxiety may occur in the general public, health staff, patients and high‐risk individuals. Anxieties associated with AIDS create confusion in the patient and chronic anxiety may generate a ‘pseudo‐AIDS’ condition, the somatic features of which may be misinterpreted as evidence of the disease. Furthermore, chronic anxiety itself may be immunosuppressive. Management requires multistage intervention involving: relaxation, cognitive techniques, peer‐group support, health education, ‘marital’ therapy, drug therapy and hospitalization. Educating patients is not enough; the general public must be continually reminded that this infection is no respector of gender or sexual orientation.