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How is female mate choice affected by male competition?

The plethora of studies devoted to the topics of male competition and female mate choice belie the fact that their interaction remains poorly understood. Indeed, on the question of whether competition should help or hinder the choice process, opinions scattered throughout the sexual selection literature seem unnecessarily polarised. We argue, in the light of recent theoretical and empirical advances, that the effect of competition on mate choice depends on whether it results in the choosy sex attaining high breeding value for total fitness, considering both direct and indirect fitness benefits. Specifically, trade-offs may occur between different fitness benefits if some are correlated with male competitive ability whilst others are not. Moreover, the costs and benefits of mating with competitive males may vary in time and/or space. These considerations highlight the importance of injecting a life-history perspective into sexual selection studies. Within this context, we turn to the sexual selection literature to try to offer insights into the circumstances when competition might be expected to have positive or negative implications for pre-copulatory female choice. In this regard, we elaborate on three stages where competition might impact upon the choice process: (i) during mate detection, (ii) mate evaluation, and (iii) in dictating actual mating outcomes. We conclude by offering researchers several potentially rewarding avenues for future research.

Animals↗

From self-prediction to self-defeat: behavioral forecasting, self-fulfilling prophecies, and the effect of competitive expectations.

Four studies explored behavioral forecasting and the effect of competitive expectations in the context of negotiations. Study 1 examined negotiators' forecasts of how they would behave when faced with a very competitive versus a less competitive opponent and found that negotiators believed they would become more competitive. Studies 2 and 3 examined actual behaviors during a negotiation and found that negotiators who expected a very competitive opponent actually became less competitive, as evidenced by setting lower, less aggressive reservation prices, making less demanding counteroffers, and ultimately agreeing to lower negotiated outcomes. Finally, Study 4 provided a direct test of the disconnection between negotiators' forecasts for their behavior and their actual behaviors within the same sample and found systematic errors in behavioral forecasting as well as evidence for the self-fulfilling effects of possessing a competitive expectation.

Adult↗

Cooperation and competition in pathogenic bacteria.

Explaining altruistic cooperation is one of the greatest challenges for evolutionary biology. One solution to this problem is if costly cooperative behaviours are directed towards relatives. This idea of kin selection has been hugely influential and applied widely from microorganisms to vertebrates. However, a problem arises if there is local competition for resources, because this leads to competition between relatives, reducing selection for cooperation. Here we use an experimental evolution approach to test the effect of the scale of competition, and how it interacts with relatedness. The cooperative trait that we examine is the production of siderophores, iron-scavenging agents, in the pathogenic bacterium Pseudomonas aeruginosa. As expected, our results show that higher levels of cooperative siderophore production evolve in the higher relatedness treatments. However, our results also show that more local competition selects for lower levels of siderophore production and that there is a significant interaction between relatedness and the scale of competition, with relatedness having less effect when the scale of competition is more local. More generally, the scale of competition is likely to be of particular importance for the evolution of cooperation in microorganisms, and also the virulence of pathogenic microorganisms, because cooperative traits such as siderophore production have an important role in determining virulence.

Altruism↗

Progression and variability of competitive performance of Olympic swimmers.

Estimates of progression and variability of athletic performance in competitions are useful for researchers and practitioners interested in factors that affect performance. We used repeated-measures mixed modelling to analyse 676 official race times of 26 US and 25 Australian Olympic swimmers in the 12-month period leading up to the 2000 Olympic Games. Progression was expressed as percent changes in mean performance; variability was expressed as the coefficient of variation in performance of an individual swimmer between races. Within competitions, both nations showed similar improvements in mean time from heats through finals (overall 1.2%; 95% confidence limits 1.1 to 1.3%). Mean competition time also improved over 12 months by a similar amount in both nations (0.9%; 95% confidence limits 0.6 to 1.2%). The US swimmers showed a greater improvement between the finals (a difference of 0.5%; 95% confidence limits -0.2 to 1.1%), which paralleled changes in the medal haul of the two nations. The coefficient of variation in performance time for a swimmer between races was 0.60% (95% confidence limits 0.56 to 0.65%) within a competition and 0.80% (95% confidence limits 0.73 to 0.86%) between competitions. Our results show that: (a) to stay in contention for a medal, an Olympic swimmer should improve his or her performance by approximately 1% within a competition and by approximately 1% within the year leading up to the Olympics; (b) an additional enhancement of approximately 0.4% (one-half the between-competition variability) would substantially increase the swimmer's chances of a medal.

Adolescent↗

Divalent cation competition with [3H]saxitoxin binding to tetrodotoxin-resistant and -sensitive sodium channels. A two-site structural model of ion/toxin interaction.

Monovalent and divalent cations competitively displace tetrodotoxin and saxitoxin (STX) from their binding sites on nerve and skeletal muscle Na channels. Recent studies of cloned cardiac (toxin-resistant) and brain (toxin-sensitive) Na channels suggest important structural differences in their toxin and divalent cation binding sites. We used a partially purified preparation of sheep cardiac Na channels to compare monovalent and divalent cation competition and pH dependence of binding of [3H]STX between these toxin-resistant channels and toxin-sensitive channels in membranes prepared from rat brain. The effects of several chemical modifiers of amino acid groups were also compared. Toxin competition curves for Na+ in heart and Cd2+ in brain yielded similar KD values to measurements of equilibrium binding curves. The monovalent cation sequence for effectiveness of [3H]STX competition is the same for cardiac and brain Na channels, with similar KI values for each ion and slopes of -1. The effectiveness sequence corresponds to unhydrated ion radii. For seven divalent cations tested (Ca2+, Mg2+, Mn2+, Co2+, Ni2+, Cd2+, and Zn2+) the sequence for [3H]STX competition was also similar. However, whereas all ions displaced [3H]STX from cardiac Na channels at lower concentrations, Cd2+ and Zn2+ did so at much lower concentrations. In addition, and by way of explication, the divalent ion competition curves for both brain and cardiac channels (except for Cd2+ and Zn2+ in heart and Zn2+ in brain) had slopes of less than -1, consistent with more than one interaction site. Two-site curves had statistically better fits than one-site curves. The derived values of KI for the higher affinity sites were similar between the channel types, but the lower affinity KI's were larger for heart. On the other hand, the slopes of competition curves for Cd2+ and Zn2+ were close to -1, as if the cardiac Na channel had one dominant site of interaction or more than one site with similar values for KI. pH titration of [3H]STX binding to cardiac channels showed a pKa of 5.5 and a slope of 0.6-0.9, compared with a pKa of 5.1 and slope of 1 for brain channels. Tetramethyloxonium (TMO) treatment abolished [3H]STX binding to cardiac and brain channels and STX protected channels, but the TMO effect was less dramatic for cardiac channels. Trinitrobenzene sulfonate preferentially abolished [3H]STX binding to brain channels by action at an STX protected site.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗

Competition in context: the politics of health care reform in Europe.

The purpose of this paper is to provide a basis for exploring the relationship between competition and quality in health care by delineating the different institutional, economic and political contexts in which pro-competitive reform was conceived and carried out in different European countries. It begins by distinguishing between national health services and social insurance systems, suggesting that different kinds of system generate different kinds of problem. Different patterns of reform in Italy, Sweden and the UK, and in France and Germany are then reviewed in turn. The paper shows how, since the end of the long boom, health systems in Europe have been exposed to a set of economic, political and ideological pressures. The way these were brought to bear meant that governments in those countries with national health services were much more disposed to radical, pro-competitive reform than others. For them, competition represented a way of managing resource constraint in an increasingly complex and demanding political environment; ideas about quality were marginal to their purpose. The paper then explores the application of competition in different contexts, first among providers and then among purchasers, for which the UK and Germany serve as examples in turn. In each case, competition is only made effective by new forms of managerial direction. Across systems, competition appears less clearly associated with quality than with political control.

Delivery of Health Care↗

Understanding the relationship between market competition and students' ratings of the managed care content of their undergraduate medical education.

PURPOSE: The increase in managed care has led to questions about the inadequacy of instruction undergraduate medical students receive in curricular areas related to managed care. This study examined (1) the percentages of graduating medical students who felt they had received inadequate instruction in six curricular content areas (CCAs): primary care, care of ambulatory patients, health promotion and disease prevention, medical care cost control, teamwork with other health professionals, and cost-effective medical practice; and (2) whether the market competitiveness of these students' medical schools affected their reports of inadequacy of instruction in these CCAs. METHOD: Data from the Association of American Medical Colleges' Graduation Questionnaires (GQs) from 1994 to 1997 were analyzed. The GQ asked graduating students to rate the adequacy of instruction they had received in the six CCAs. Students' ratings were collapsed into the dichotomous variables "inadequate" and "not inadequate." The market competitiveness of medical schools was determined using the four-stage Market Evolution Model developed by the University HealthSystem Consortium. Only responses from students graduating from medical schools that could be staged for all four years of the study were analyzed. Statistical analyses were performed to determine trends for each CCA by year, across the entire study period, by market stage, and by market stage across the entire study period. RESULTS: A total of 39,136 respondents from 86 medical schools were used in the study. The percentages of graduating medical students who reported inadequate instruction decreased over the study period for five of the six CCAs: primary care (27.6% in 1994 to 13.7% in 1997), ambulatory care (37.4% to 23. 9%), medical care cost control (62.9% to 52.9%) cost-effectiveness of medical practice (62.7% to 53.9%), and health promotion and disease prevention (44.4% to 23.7%); all at p <0.001. The responses for inadequacy of instruction for teamwork with other health professionals remained steady from 1994 to 1996 (10.2% to 10.6%), then increased 21.8% in 1997. Over the course of the study, students graduating from schools in more competitive markets (Stage 3 or Stage 4) were more likely to report inadequate instruction in three CCAs, primary care, ambulatory care, and health promotion and disease prevention, than were those graduating from schools in less competitive markets (Stage 1 and Stage 2). Conversely, students graduating from schools in the more competitive health care markets were less likely to report inadequate instruction in cost-effectiveness and cost control than were students from schools in less competitive markets. CONCLUSION: Graduating students' reports of inadequacy of instruction decreased over the study period for five of the six CCAs, increasing only for teamwork with other professionals. Findings were mixed with regard to the relationship of medical schools' market competitiveness and graduating students' reports of inadequacy of instruction. More research is needed to confirm graduating students' perceptions of the inadequacy of their instruction in CCAs related to managed care, particularly once they have gained experience treating patients in managed care environments.

Ambulatory Care↗

Competition performance and basal nocturnal catecholamine excretion in cross-country skiers.

UNLABELLED: Objective techniques to determine whether an athlete is optimally prepared for a competition are virtually nonexistent. Preparedness for sports competition is commonly judged through the experience of the athletes and their coaches. Evidence from overtraining studies suggests that catecholamine (Cat) excretion rates may correlate with performance in athletes. PURPOSE: We therefore attempted to determine whether a relationship existed between performances of world-class cross-country skiers and basal nocturnal Cat excretion (BNCE). METHOD: During the Cross-Country Skiing World Championships, we determined BNCE in nine cross-country skiers of the Swiss national team by measuring free Cat concentration (dopamine = D, norepinephrine = NE, epinephrine = E) in morning urine samples, using high performance liquid chromatography. Expert judgments of competition performance (ECP) were assessed by two experienced professional coaches of the national team by using an 11-step scale. RESULTS: The BNCE correlated significantly with ECP in cross-country skiers (r2 = 0.84 and P < for NE; r2 = 0.86 and P < 0.001 for D). Athletes who had their best absolute competition results (ACR) showed the highest NE and D concentrations. CONCLUSION: These data suggest that competitive cross-country skiers with higher D and NE excretion may reach better competition levels compared with those with lower levels. Measures of BNCE provide objective information about competition performance, which may benefit athletes in their precompetition preparation.

Adult↗

Interference competition and species coexistence.

Interference competition is ubiquitous in nature. Yet its effects on resource exploitation remain largely unexplored for species that compete for dynamic resources. Here, I present a model of exploitative and interference competition with explicit resource dynamics. The model incorporates both biotic and abiotic resources. It considers interference competition both in the classical sense (i.e. each species suffers a net reduction in per capita growth rate via interference from, and interference on, the other species) and in the broad sense (i.e. each species suffers a net reduction in per capita growth rate via interference from, but can experience an increase in growth rate via interference on, the other species). Coexistence cannot occur under classical interference competition even when the species inferior at resource exploitation is superior at interference. Such a trade-off can, however, change the mechanism of competitive exclusion from dominance by the superior resource exploiter to a priority effect. Now the inferior resource exploiter can exclude the superior resource exploiter provided it has a higher initial abundance. By contrast, when interference is beneficial to the interacting species, coexistence is possible via a trade-off between exploitation and interference. These results hold regardless of whether the resource is biotic or abiotic, indicating that the outcome of exploitative and interference competition does not depend on the exact nature of resource dynamics. The model makes two key predictions. First, species that engage in costly interference mechanisms (e.g. territoriality, overgrowth or undercutting, allelopathy and other forms of chemical competition) should not be able to coexist unless they also engage in beneficial interference mechanisms (e.g. predation or parasitism). Second, exotic invasive species that displace native biota should be superior resource exploiters that have strong interference effects on native species with little or negative cost. The first prediction provides a potential explanation for patterns observed in several natural systems, including plants, aquatic invertebrates and insects. The second prediction is supported by data on invasive plants and vertebrates.

Animals↗

Cost convergence between public and for-profit hospitals under prospective payment and high competition in Taiwan.

OBJECTIVE: To test the hypotheses that: (1) average adjusted costs per discharge are higher in high-competition relative to low-competition markets, and (2) increased competition is associated with cost convergence between public and for-profit (FP) hospitals for case payment diagnoses, but not for cost-plus reimbursed diagnoses. DATA SOURCES: Taiwan's National Health Insurance database; 325,851 inpatient claims for cesarean section, vaginal delivery, prostatectomy, and thyroidectomy (all case payment), and bronchial asthma and cholelithiasis (both cost-based payment). STUDY DESIGN: Retrospective population-based, cross-sectional study. DATA ANALYSIS: Diagnosis-wise regression analyses were done to explore associations between cost per discharge and hospital ownership under high and low competition, adjusted for clinical severity and institutional characteristics. PRINCIPAL FINDINGS: Adjusted costs per discharge are higher for all diagnoses in high-competition markets. For case payment diagnoses, the magnitudes of adjusted cost differences between public and FP hospitals are lower under high competition relative to low competition. This is not so for the cost-based diagnoses. CONCLUSIONS: We find that the empirical evidence supports both our hypotheses.

Economic Competition↗

Effect of competition on performance of thoroughbred racehorses.

The effect of competition and the influence of age and sex on performance were examined in a study of 18 Thoroughbred racehorses. The horses performed two solo and two competitive runs at 1,200 and 1,600 m for a total of eight runs. No group ran faster during competition, which may have been a reflection of the quality of horses used for this study and their susceptibility to stress-induced impairment of performance. Males showed no significant difference between competitive and solo run times, whereas females were consistently slower during competition. Males ran significantly faster than females in all runs. There was no difference in run times due to age, which may have been due to the high mean age (5.9 yr) of the group. The slower competitive run times may have occurred because of an earlier onset of fatigue when compared with solo runs. Plasma lactate was significantly greater for the 1,200-m competitive than for the solo runs.

Age Factors↗

Competitive surfing injuries: a prospective study of surfing-related injuries among contest surfers.

BACKGROUND: Surfing is a sport that has been growing rapidly in popularity, yet little is known about surfing injuries. PURPOSE: To calculate an accurate injury rate for competitive surfing and to describe the relative frequency, mechanisms, and risk factors for acute surfing injuries. STUDY DESIGN: Descriptive epidemiology study. METHODS: This prospective study of acute competitive surfing injuries was carried out at 32 professional and amateur surfing contests worldwide between 1999 and 2005. All acute injuries sustained during competition were recorded by on-site medical personnel. The wave size, type of seafloor, and number of surfing heats were also recorded for each day. The total number of injuries was divided by the total number of athlete exposures to determine injury rates. A multiple logistic regression was used to determine risk factors for injury. RESULTS: There were 116 injuries documented, 89 of which occurred during competition. There were 15,675 athlete exposures, yielding an injury rate of 5.7 per 1000 athlete exposures, or 13 per 1000 hours of competitive surfing. There were 6.6 significant injuries per 1000 hours of competitive surfing. Risk of injury was 2.4 (95% confidence interval, 1.5-3.9) times greater when surfing in waves overhead or bigger relative to smaller waves and 2.6 (95% confidence interval, 1.3-5.2) times greater when surfing over a rock or reef bottom relative to a sandy bottom. CONCLUSION: There were 13 acute surfing injuries per 1000 hours of competitive surfing. The risk of injury was more than doubled when surfing in large waves or over a hard seafloor.

Athletic Injuries↗

Do HMO penetration and hospital competition impact quality of hospital care?

This study examines the impact of HMO penetration and competition on hospital markets. A modified structure-conduct-performance paradigm was applied to the health care industry in order to investigate the impact of HMO penetration and competition on risk-adjusted hospital mortality rates (i.e. quality of hospital care). Secondary data for 1957 acute care hospitals in the USA from the 1991 American Hospital Association's Annual Survey of Hospitals were used. The outcome variables were risk-adjusted mortality rates in 1991. Predictor variables were market characteristics (i.e. managed care penetration and hospital competition). Control variables were environmental, patient, and institutional characteristics. Associations between predictor and outcome variables were investigated using statistical regression techniques. Hospital competition had a negative relationship with risk-adjusted mortality rates (a negative indicator of quality of care). HMO penetration, hospital competition, and an interaction effect of HMO penetration and competition were not found to have significant effects on risk-adjusted mortality rates. These findings suggest that when faced with intense competition, hospitals may respond in ways associated with reducing their mortality rates.

Economic Competition↗

A worksite smoking modification competition: potential for public health impact.

We evaluated the effectiveness of a worksite smoking cessation/reduction program both with and without formal competition for monetary prizes in five worksites (n = 107). A greater percentage of eligible smokers participated in the competition (88 per cent) than the non-competition (53 per cent) condition. Treatment outcome among participants was generally equivalent across conditions, but at a six-month follow-up, nonabstinent subjects in the competition condition had lower levels of carbon monoxide than subjects in the non-competition condition. On a worksite-wide basis, a higher percentage of employees quit smoking in the competition condition (16 per cent) compared to the non-competition (7 per cent).

Analysis of Variance↗

Competitiveness among Japanese, Chinese, and American undergraduate students.

Although research indicates that competitiveness, defined as the desire to win in interpersonal situations, is an important individual difference that influences a range of social interactions, little research has focused on competitiveness in cultures outside the United States. This study investigated competitiveness in three cultures by comparing Chinese (n=61), Japanese (n=232), and American (n=161) undergraduate college students. Nationality and sex were compared on two scales of the revised Competitiveness Index. Analysis indicated that American students scored higher on Enjoyment of Competitiveness than Chinese and Japanese students, but no difference was found on Contentiousness. Men scored higher than women on Enjoyment of Competition but not on Contentiousness. The findings indicate that sex and cultural patterns influence some but not all aspects of competitiveness.

Adolescent↗

[Formation of grand coalition when consciousness of intragroup competition is activated].

The purpose was to explore conditions encouraging to form grand coalition, which leads a group to high solidarity with strong consciousness of intragroup competition. Subjects, 64 male undergraduates, were divided into 16 groups of four persons each. Experiment was carried out with 2 x 2 design of (consciousness of intergroup competition: strong vs. weak) (consciousness of intragroup competition: strong vs. weak). Results showed that strong competitive spirits against other groups produced facilitative effects on formation of grand coalition even when the consciousness of intragroup competition was strong, and the facilitative effects were strong even when consciousness of intragroup competition was weak. In addition, the necessary conditions for group members to form grand coalition under strong intragroup competition were discussed.

Adult↗

Clusters and the new economics of competition.

Economic geography in an era of global competition poses a paradox. In theory, location should no longer be a source of competitive advantage. Open global markets, rapid transportation, and high-speed communications should allow any company to source any thing from any place at any time. But in practice, Michael Porter demonstrates, location remains central to competition. Today's economic map of the world is characterized by what Porter calls clusters: critical masses in one place of linked industries and institutions--from suppliers to universities to government agencies--that enjoy unusual competitive success in a particular field. The most famous example are found in Silicon Valley and Hollywood, but clusters dot the world's landscape. Porter explains how clusters affect competition in three broad ways: first, by increasing the productivity of companies based in the area; second, by driving the direction and pace of innovation; and third, by stimulating the formation of new businesses within the cluster. Geographic, cultural, and institutional proximity provides companies with special access, closer relationships, better information, powerful incentives, and other advantages that are difficult to tap from a distance. The more complex, knowledge-based, and dynamic the world economy becomes, the more this is true. Competitive advantage lies increasingly in local things--knowledge, relationships, and motivation--that distant rivals cannot replicate. Porter challenges the conventional wisdom about how companies should be configured, how institutions such as universities can contribute to competitive success, and how governments can promote economic development and prosperity.

Commerce↗

[Competitiveness in science. Today, tomorrow, and forever].

Paternalistic governments and highly bureaucratized administrations produce mediocre science policy decisions that often allow for the co-existence of potentially competitive scientists alongside with those that are not. This invariably results in failure to produce significant research. It seems apparent therefore, that policy change aiming at improving science and technology must begin with intensification of the level of individual competitiveness. Nations that have internationally competitive levels of technical and scientific activity such as Japan, USA and Canada, share in common certain features that foster individual competitiveness despite the fact that their socioeconomic basis are vastly different. These common features include administrative continuity, very high academic standards and a highly educated work force. The scientist's emotional cost in competitive environments is high but there seems to be no alternative given the sophistication of the topics that are dealt with in formerly purely descriptive sciences such as biomedicine, and given the enormous speed of electronic communications. The role of governments in fostering science and technology should be mainly concerned with conducting a sound fiscal policy in order to provide for the needs of education and scientific activity. Governments can also play a key role in insuring that science remains competitive through the delineation of rules that increase individual competitiveness rather than with policy schemes that fail to directly address the responsibility of the individual. Policies to increase individuals' performance may prove costly to politicians given that these adjustments imply unpopular decisions regarding an increase in academic performance expectation beginning in high school and the re-assignment of functions of individuals or institutions that do not meet international productivity criteria.

Academies and Institutes↗