The biochemistry, haematology, nutrition and racing performance of two-year-old thoroughbreds throughout their training and racing season.
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An adaptation in one lineage (e.g. predators) may change the selection pressure on another lineage (e.g. prey), giving rise to a counter-adaptation. If this occurs reciprocally, an unstable runaway escalation or 'arms race' may result. We discuss various factors which might give one side an advantage in an arms race. For example, a lineage under strong selection may out-evolve a weakly selected one (' the life-dinner principle'). We then classify arms races in two independent ways. They may be symmetric or asymmetric, and they may be interspecific or intraspecific. Our example of an asymmetric interspecific arms race is that between brood parasites and their hosts. The arms race concept may help to reduce the mystery of why cuckoo hosts are so good at detecting cuckoo eggs, but so bad at detecting cuckoo nestlings. The evolutionary contest between queen and worker ants over relative parental investment is a good example of an intraspecific asymmetric arms race. Such cases raise special problems because the participants share the same gene pool. Interspecific symmetric arms races are unlikely to be important, because competitors tend to diverge rather than escalate competitive adaptations. Intraspecific symmetric arms races, exemplified by adaptations for male-male competition, may underlie Cope's Rule and even the extinction of lineages. Finally we consider ways in which arms races can end. One lineage may drive the other to extinction; one may reach an optimum, thereby preventing the other from doing so; a particularly interesting possibility, exemplified by flower-bee coevolution, is that both sides may reach a mutual local optimum; lastly, arms races may have no stable and but may cycle continuously. We do not wish necessarily to suggest that all, or even most, evolutionary change results from arms races, but we do suggest that the arms race concept may help to resolve three long-standing questions in evolutionary theory.
Changes in concentration of a number of blood metabolites in 30 thoroughbred horses were recorded after an 1110 metre race. No significant changes occurred in blood urea or aspartate aminotransferase during the three hours after racing. Plasma sodium, potassium and calcium levels were increased immediately after racing but had returned to normal one hour after racing. Plasma phosphate showed a significant fall in concentration one hour after racing. Creatinine and lactic acid concentrations were elevated ten minutes after racing and although they subsequently decreased, the level of lactic acid was still significant one hour later. Uric acid levels were well above resting levels at ten minutes after racing but rose even more in the subsequent hour. Urinary uric acid levels were also elevated during this time. Three hours after racing some horses still had elevated plasma uric acid levels and all of them showed a significant rise in creatine phosphokinase. The possible physiological basis of these findings is discussed.
Reaction of the strains of the tularemia causative agent to erythromycin (100 gamma/ml) or oleandomycin (400 gamma/ml) is one of the taxonomic tests. The study of 82 strains of the holarctic race and 63 strains of the Central Asiatic race according to this test showed that the strains of the holarctic race were divided with respect to these macrolides into sensitive (biotype I) and resistant (biotype II). The strains of the both races were isolated at the territory of the Kazakh SSR. Such a reaction of the strains of the holarctic race is a stable feature and is not connected with virulence, the isolation source and the biochemical properties of the strains. Division of the holarctic race into the biotypes (I and II) with respect to erythromycin and oleandomycin may be of definite significance in epidemiological and epizootological examination for tularemia with a purpose of determining the source of the infection, as well as in defining the borders of the infection focus area with circulation of this or that biotype of the holarctic race of the tularemia causative agent.
The major problems of racing in the United States at the present time are caused by too much racing. This has led to too few horses and small fields. Consequently many owners and trainers are trying to enter their horses too frequently and to race them when they are not really fit to run. The desire to race horses as frequently as possible has led to constant pressure from horsemen through their organizations for so called "permissive medication". Started in the state of Colorado approximately ten years ago this has grown until finally there are only a few states, notably New York and New Jersey that have resisted the pressure. The drug that gave the opening wedge to permissive medication was phenylbutazone, but this in many states has led to the inclusion of other drugs including analgesics and drugs that veterinarians claim are needed for therapeutic purposes. Some states have endeavoured to control phenylbutazone medication by quantitation and while lower limits cause little difficulty, maximum allowable limits have caused problems and are not practical. While there has been no publicity to my knowledge about frusemide (furosemide, lasix) the abuse of this drug for so called "bleeders" is an example that may seriously interfere with drug detection in urine and its use should be confined to proven "bleeders" (i.e. horses suffering from epistaxis). Pre-race blood testing began roughly ten years ago at the harness tracks and has been resisted by our flat tracks rather successfully up to the present time. The blood testing methods and those used by the same laboratories in post-race urine testing is inadequate and will not detect many illegal drugs.
PURPOSE: Despite 5-year survival rates of over 90% among children and adolescents/young adults (CAYAs) with classic Hodgkin lymphoma (cHL), 15%-20% relapse after frontline therapy. Prior analysis of frontline Children's Oncology Group (COG) clinical trials demonstrated that, despite similar rates of relapse, non-Hispanic Black (NHB) and Hispanic (vs. non-Hispanic White [NHW]) patients experienced higher post-relapse mortality. It is unknown whether post-relapse disparities persist when second-line treatment is delivered in a cooperative group trial setting. We examined overall survival (OS) by race and ethnicity in CAYAs enrolled in COG trials for relapsed/refractory (r/r) cHL. METHODS: A pooled analysis of individual-level data from CAYAs (≤ 29 years) receiving therapy for r/r cHL on COG clinical trials (2001-2016) was conducted. The Kaplan-Meier method estimated 3-year OS by racial and ethnic groups. Cox regression models examined associations of race and ethnicity and OS, adjusted for age, insurance, first versus ≥2 relapse, and time from initial diagnosis to relapse trial enrollment. RESULTS: Among 175 CAYAs treated on COG trials for r/r cHL (5.7% Asian or Pacific Islander, 14.9% Hispanic, 14.3% NHB, 61.7% NHW, 3.4% other), at median follow-up of 4.9 years, 3-year OS was 82.1% (95% confidence interval [CI], 75.3%-87.1%) and did not differ by race and ethnicity (p = 0.36). In multivariable analyses, shorter time from diagnosis to relapse trial enrollment (p = 0.01) and ≥2 relapses (vs. first, p = 0.004) conferred worse OS, with no significant effect of race and ethnicity (p = 0.43). CONCLUSION: Post-relapse survival did not differ by race and ethnicity among CAYAs enrolled in COG trials for r/r cHL, suggesting access to clinical trials may mitigate OS disparities.
To characterize the lipid and the energy metabolism in the livers of genetically different types of pigs (land race pig and mini pig), the authors determined the activities of enzymes typical of and limiting these metabolic pathways. Furthermore, they measured the concentrations of typical metabolites and ascertained parameters that are of importance in energy metabolism. The concentrations of acetyl CoA and free fatty acids in the livers of mini pigs were significantly greater than those in the livers of land race pigs, whereas the cholesterol, glycerol, triglyceride and acetoacetate concentrations were reduced. The activities of glucose-6-phosphate dehydrogenase (E.C.1.1.1.49.), citrate synthase (E.C.4.1.3.7.) and ATP citrate lyase (E.C.4.1.3.8.) were lower in the livers of mini pigs than in the livers of land race pigs, whereas the activity of fatty acid synthase was higher. The concentrations of cyclic 3',5'-adenosine monophosphate (AMP) and adenosine diphosphate (ADP) were lower in the livers of mini pigs than in those of land race pigs. In land race pigs, the metabolic process seems, therefore, to be determined in favour of the degradation of free fatty acids and of the generation of energy. In mini pigs, lipogenesis in the liver appears to be the decisive metabolic pathway. The possibility of a higher coordinating control mechanism of the lipid and the energy metabolism is discussed.
Five marathon runners participated in a visual sustained attention experiment 1 week prior to a competitive martathon race and from 1.5 to 8.5 h following the race. The task was designed to help assess changes in central nervous system function by examinining both behavioral deficits and electroencephalogram (EEG) visual evoked potentials as a function of the race. A significant increase in heart rate was observed during the behavioral task. No changes in any of the wave forms of the EEG visual evoked response were observed during the vigilance task as a function of the race. Sustained visual attention responses were unchanged for correct detections, but post-marathon performance gave significantly fewer false positive responses. The results provided evidence that central nervous system dysfunction was not observed following the completion of a competitive marathon race.
PURPOSE: Education is important for lifelong skills and economic growth; however, student placement decisions may be shaped by social biases. As genomic information captured via polygenic scores becomes more available, it may also inform student placement decisions. We assessed the intersectional effects of polygenic scores, race, disability, and socioeconomic status on US adults' views of educational trajectories using an online experimental survey design. METHODS: A total of 1367 US adults were randomized to one of 16 conditions and prompted to read a short vignette about a boy named Michael, also depicted in an image. Each condition varied Michael's race (Black/White), disability (wheelchair user/no), socioeconomic status (high/low), and polygenic score (high/low) for educational attainment (EA-PGS). After reading the vignette, the respondents were asked to answer multichoice questions about Michael's immediate and long-term educational trajectories. RESULTS: Variation in Michael's EA-PGS strongly influenced participants' expectations regarding (1) the most appropriate immediate educational program for Michael (ie, general, special, or gifted education), (2) whether he would graduate high school, and, if so, (3) the highest educational degree he would complete in his lifetime (associate, bachelor, master, or PhD). Across these responses, high EA-PGS was associated with more socially desirable outcomes, whereas the opposite was true for low EA-PGS. Depicting Michael in a wheelchair significantly influenced respondents' expectations that his most appropriate immediate educational trajectory would be special. There were significant interactions between Michael's race, disability, socioeconomic status, and the EA-PGS. CONCLUSION: Information about children's EA-PGS may affect their views about their immediate and long-term educational trajectories. The negative effects of low EA-PGS were comparable to those of high EA-PGS. The EA-PGS may be interpreted in ways that compound the existing stereotypes related to a child's race, disability, and socioeconomic status.
Aortas and coronary arteries from 23,000 autopsies of 19 location-race groups (L/R) were graded for % surface fatty streaks (FS), fibrous plaques (FP) and advanced lesions (AL = calcified, hemorrhagic, ulcerated, or thrombotic). Cases were classed by age (24-34, 35-44, 45-54, 55-64, and 65-69), sex, L/R, broad cause of death category (C/D; athero = related to atherosclerosis; basal = all other), and % surface raised lesions (RL = FP + AL). AL was converted to "advanced among lesions" (AaR = AL divided RL) because AaR was found on the average within each subgroup of subjects to hold a nearly constant ratio to RL (i.e. AaR : RL = K, an empirical constant). This ratio was different for each age (older greater than younger), C/D (athero greater than basal), and sex (M greater than F) subgroup and for coronary vs. aorta, thus requiring 5 X 2 X 2 X 2 = 40 values of K to describe the pools of subjects. The values of K were essentially same for all 19 location-race groups. If it be assumed that advanced lesions arise only be evolution from fibrous plaques, then the speed of this evolution up to each specified age is measured by K, in the sense that at a particular age larger K implies faster evolution. On the average, the rate of evolution in this sense was found to be the same in all location-race groups. Within groups a large variability of K among individuals was found, and this variation remains unexplained. However, across location-race boundaries no such variability was found, and this implies that the magnitude of K is not under control of geographically variable factors.
In a 28 week study, 18 racing sled dogs were trained to maximal fitness in 12 weeks, sustained through a racing season of 12 weeks, followed by gradual of training of 4 weeks. The dogs were fed a predominantly cereal diet prior to the study; experimental diets containing more chicken and meat by products were introduced from the 2nd to the 4th week of training. On an energy basis, the diets contained protein, fat, and carbohydrate in the proportions of 39:61:0 (diet A), 32:45:23 (diet B), and 28:34:38 (diet C). Blood samples were taken at rest just before the start of training, at 6, 12,24 and 28 weeks; 33 variables were measured on most samples. The results were subjected to analysis of variance. No adverse effects were observed in dogs fed the extreme diet A. Significant relationships to training were shown by serum glutamic oxaloacetic transaminase, creatinine, packed cell volume, calcium, hemoglobin, and globulin. Serum cholesterol concentration increased with the introduction of the higher protein-fat diets; the high concentrations attenuated with time but rose again when training was abated. Dogs on diet A maintained higher serum concentrations of albumin, calcium, magnesium, and free fatty acids during the racing season than did dogs fed diets B or C. They also exhibited the greatest increases in red cell count, hemoglobin concentration, and packed cell volume during training. High values of red cell indices were not sustained through the racing season in dogs fed diet C. In addition to attributes already widely appreciated, viz. a higher energy density an digestibility, the carbohydrate-free, high-fat diet A appeared to confer advantages for prolonged strenuous running in terms of certain metabolic responses to training.
BACKGROUND: High-sensitivity cardiac troponin I assays enable early exclusion of myocardial infarction in the emergency department. However, the clinical implications of detectable troponin values below the 99th percentile upper reference limit (4-18 ng/L) remain unclear. OBJECTIVE: To assess the association between subthreshold troponin levels and 30-day outcomes in patients from the RACE-IT trial, using exact troponin values when available. METHODS: This post-hoc analysis of the RACE-IT stepped-wedge randomized controlled trial included patients with troponin ≤ 18 ng/L across nine EDs. Patients were stratified by initial troponin, peak value, absolute change, and percent change. The primary outcome was a 30-day composite of all-cause death, acute MI, percutaneous coronary intervention, and coronary artery bypass grafting. Logistic regression analysis after adjusting for age, sex, race, and coronary artery disease was performed. RESULTS: Among 19,194 patients with troponin ≤ 18 ng/L, 117 (0.6%) experienced the composite outcome. Higher troponin levels were associated with increased event rates in unadjusted analyses. Adjusted analyses showed no independent associations overall, though patients whose highest troponin values fell within the ≥ 11- ≤ 18 ng/L range continued to demonstrate significantly worse outcomes than those with lower peak levels. Elevated troponin values correlated with older age, male sex, and greater comorbidity burden. CONCLUSION: In this post-hoc analysis of patients with troponin values below the 99th percentile URL, absolute levels and temporal changes were not independently associated with 30-day adverse outcomes. These findings support the use of subthreshold troponin values in rapid rule-out protocols, emphasizing the need to consider clinical context and comorbidities in risk assessment.
A battery of 24 discrete cranial traits has been tested for its power to discriminate within- and between-race distances for the two principal North American indigenous populations: Indian (7 samples, N = 366) and Eskimo (7 samples, N = 451). One of the Indian samples, Dakota Sioux, has been split according to tribal subdivisions, the intra-tribal mean distance providing a parameter of very close relationship. In addition, two Negro samples provide a parameter of relationship phylogenetically remote from the Amerinds. Separate male-female analysis of the three largest samples indicates that distances for pooled samples are not seriously affected by the sex component. Within-race distances (C. A. B. Smith's Measure of Divergence, MD), are smaller than between-race at the .00001 level of significance (Mann-Whitney U test) for both Indian-Eskimo and Amerind-Negro comparisons. The features most powerful for Indian-Eskimo and Amerind-Negro comparisons. The features most powerful for Indian-Eskimo discrimination are revealed by their percent contribution to the mean of 49 MD's. The African heritage of American Blacks is reflected in a characteristic Negro pattern of trait frequencies different from the Amerind. This battery of features yields valid taxonomical information useful in conjunction with other physical data to reconstruct affinities of extinct populations.
Nationwide rates of death from systemic lupus erythematosus (SLE) were estimated from National Center for Health Statistics mortality data for 1968 to 1972 according to age, sex, and race. The overall rates for females, 6.3 per million person-years (whites 5.2, blacks 14.8), were about four times that for males, 1.6 per million person-years (whites 1.5, blacks 2.2). The overall rate for blacks, 8.8, was 2.6 times that for whites, 3.4. An earlier rise in age-specific mortality rates for females than males produced higher age-specific female-to male sex ratios in the early adult years than in later years. Mortality generally increased with age in whites whereas the phenomenon of an accentuation and decline during the early and middle adult ages was seen in blacks, particularly females. Analysis of age-, sex-, race-specific rates using one measure of synergistic interaction, S, revealed substantial synergy between the effects of sex and race on mortality during the childbearing ages (S = 3.2, 95% confidence interval = 2.3--4.4).
In a study designed to test for sex- and race-related bias in psychiatric diagnosis, the responses of 173 mental health professionals to four hypothetical patient profiles were analyzed. Minimal racial bias was observed. In some instances, therapists appeared more likely to make judgments biased against patients who were of the same race and sex as themselves. The results support the contention that hysterical and antisocial personality disorders are sex-biased diagnoses. The race of the therapist strongly influenced diagnosis. It is argued that this finding reflects resistance of nonwhite therapists to a majority-group-dominated diagnostic theory. Professional discipline rarely affected diagnosis with the exception that psychiatrists were more prone to diagnose psychosis.