Thorax Width Research Articles

Morphological description of the Lipizzan horse population

Morphological measurements of Lipizzan horses from state-owned studs in seven countries in Central and South-east Europe (Austria, Croatia, Hungary, Italy, Romania, Slovakia and Slovenia) were recorded to characterise the base population of Lipizzan horse breeding. A total of 37 distance and angular measures were taken from 368 breeding mares and 145 stallions from eight studs (one stud from each country with the exception of Romania, where horses were measured at two studs). Significant differences between studs were found for most of the traits (34 of 37 for mares, 29 of 37 for stallions). Repeatabilities of measurements (based on two repetitions in 100 horses) varied from 0.24 to 0.95. Some of the measurements most frequently taken in horse breeding showed high repeatabilities (0.95 for height at withers and cannon bone circumference), but chest girth showed a rather low repeatability of 0.45. Heritabilites of the traits varied from 0.00 to 0.55. Estimates were comparable to literature results but due to the small data set (only the 368 mares were used for analysis) they were partly inconsistent. Multivariate analyses were applied separately to mares and stallions. Length of neck, cannon bone circumference, and width of thorax were the most important traits for discriminating studs for mares; width of thurls, chest circumference, and width of hips were important for stallions. Mahalanobis distances based on all 37 measurements were significant for pairwise comparison of all studs. An analysis of the differences of sire lines showed no significance. The results reflect at least partially different breeding goals.

Thymus size and its relationship to perinatal events.

A retrospective study was conducted to assess radiographically the thymus size in well and sick neonates and to search for a possible relationship to perinatal events. Thymus size was expressed as cardiothymic:thoracic ratio (CT/T) by measuring the width of the cardiothymic shadow at the level of carina and dividing it by the width of the thorax at the costophrenic angles. The CT/T was measured on chest radiographs obtained on day 1 in well term neonates consecutively born in our nursery and sick neonates with meconium staining of the amniotic fluid, meconium aspiration syndrome or respiratory distress syndrome (RDS). Neonates with congenital anomalies, congenital heart disease or intrauterine growth retardation were excluded. There were no significant relationships between CT/T and sex, birth route, birthweight or gestational age in well and sick term neonates. The CT/T were comparable among well and sick term neonates and were significantly greater in the preterm neonates with RDS than in the preterm neonates without RDS. The CT/T was correlated to the birth route only in the preterm neonates. We conclude that thymus involution in the perinatal period is a complex process and the response is different between term and preterm neonates.

Change in sexual size dimorphism as a correlated response to selection on fecundity

Fecundity selection is often suggested as the main causal factor underlying the prevalence of female-biased sexual size dimorphism (SSD), but this assumption has not been empirically tested. We selected female Drosophila melanogaster for increased or decreased fecundity (eggs laid over a single 18-h period, between days 5 and 7 posteclosion) for 20 generations, to see what effect this would have on SSD in three morphological traits (thorax width, abdomen width and thorax length). A direct response to fecundity selection was found in the downward direction (16.6%), whereas the response to upward selection (5.7%) was not statistically significant. Significant sex by selection interaction terms in the ANOVAs for thorax width and abdomen width indicate that the two sexes responded differently. Females usually showed a greater correlated response than males. In lines selected for increased fecundity, the correlated response in females for thorax and abdomen width was greater than the direct response in standard deviation units. SSD generally increased with selection for increased fecundity, but showed no consistent trend with selection for decreased fecundity. These results support the general hypothesis that SSD can evolve rapidly in response to fecundity selection. Selection on fecundity also produced correlated responses in life history traits. Downward selection resulted in flies that had lower viability and longevity, and both directions of selection were associated with an increase in development time.

Queen dimorphism and reproductive capacity in the ponerine ant, Ectatomma ruidum Roger.

We report here the first case of queen dimorphism in a ponerine ant species. A total of 550 colonies of the Neotropical ponerine ant Ectatomma ruidum, from two natural populations in southeastern Mexico, were investigated for polymorphism and reproductive function within the queen caste. The distribution of different morphological traits (head and thorax widths, and scutum and alitrunk lengths) was shown to be bimodal. Thorax width and head width were significantly isometric for both macro- and microgynes and thorax proportions did not change with the category of the queen. Microgynes appear as an isometric reduction of the normal queens. On average, macrogynes were found to be approximately 20% larger in size and twice as heavy as microgynes (and up to three times heavier in terms of dry weight). Their wing surface was 72% greater. There was no difference between the two morphs in terms of their capacity to be inseminated and all dealate females present in natural colonies could be considered as true potentially reproductive queens whatever the class to which they belonged. Ovary size, number of ovarioles per ovary, and number of mature oocytes produced were significantly higher for macrogynes than for microgynes, but small queens were able to function as active egg-layers. However, the number of egg-laying individuals was significantly lower for this form, although egg-laying activity appeared to be independent of queen weight. Despite its markedly reduced reproductive capacity compared to macrogynes, the distribution of the microgyne form of E. ruidum in both studied populations was very broad, reaching one-third of all alate and dealate females and extending to one-third of all colonies. In 72.2% of the colonies where alate and/or dealate microgynes were present, both forms co-occurred. Fat content analysis results supported the idea that semi-claustral independent colony founding, typical for this species, would essentially be achieved by macrogynes, while microgynes would be adopted by established colonies. We argue that queen dimorphism in E. ruidum could represent an attractive alternative dispersal strategy for female sexuals. The small females may constitute an important reserve of potential reproductives at a very low energetic cost to the colony, the production of a macrogyne being about 7.5 times more costly than a microgyne. The significantly greater `wing surface/body weight' ratio of microgynes also suggests their greater capacity for dispersion. The combination of such a capacity for microgynes, along with their ability to contribute in the production of both female morphs, including the reproductively efficient macrogynes, would contribute to insuring genetic reassortment at the population level and could explain, in part, the ecological success of E. ruidum in Neotropical zones.

Evolution of genetic variation for condition-dependent traits in stalk-eyed flies

Sexual selection has been proposed to increase genetic variation for condition-dependent ornaments. The condition capture model predicts the genetic variance for a sexually selected trait from the genetic variance in condition and the slope of the relationship between the ornament and condition. Assuming that body size reflects condition we assess the efficacy of this model using six species of stalk–eyed flies (Diopsidae). Prior evidence indicates that male eye span exhibits strong condition dependence and is under sexual selection in sexually dimorphic but not monomorphic species. In contrast, thorax width is weakly related to condition and probably under stabilizing selection. We estimated additive genetic variances for eye span, body length and thorax width from half–sib breeding studies and found that the condition capture model explained 97% of the variation in eye span genetic variance but only 7% of thorax width genetic variance. Comparison of phylogenetically independent contrasts revealed that evolutionary change in male eye span genetic variance is due to evolutionary change in the allometric relationship between eye span and condition: not to evolutionary change in genetic variance for condition. These results suggest that sexual selection can accelerate evolutionary change in condition-dependent male ornaments by increasing the genetic variation available for selection.

Body build structure of neonates

The paper presents anthropometric data on 292 healthy neonates delivered of normal births at the Women's Hospital of Tartu University (150 boys and 142 girls). The parameters of the neonates' physical development measured included height, weight, sitting height, length of sternum and abdomen, shoulder width, upper and lower width and depth of thorax, width and depth of abdomen, D. cristarum, D. trochanterica, pelvic depth, 12 circumferences, foot length and two skinfolds (on abdomen and back). The mean weight of a neonate was 3620.5 g±448.7 g (minimum 2400 g and maximum 4854 g). Boys were somewhat heavier than girls (3684.7 g and 3551.3 g respectively). The average height of the infants was 49.9 cm±1.9 cm (minimum 44 cm and maximum 54.5 cm). Correlation analysis of the characteristics showed that body structure is a system of wellcorrelated anthropometric measurements where the leading role belongs to height and weight. The changes in the relation between height and weight (height-weight classification in 3×3SD classes) cause systemic changes in other measurements. Therefore, in further micropaediatric and clinical research, the height-weight classification could be used as the primary model of the body as a whole.

SEXUAL SIZE DIMORPHISM AS A CORRELATED RESPONSE TO SELECTION ON BODY SIZE: AN EMPIRICAL TEST OF THE QUANTITATIVE GENETIC MODEL.

We artificially selected for body size in Drosophila melanogaster to test Lande's quantitative genetic model for the evolution of sexual size dimorphism. Thorax width was used as an estimator of body size. Selection was maintained for 21 generations in both directions on males only, females only, or both sexes simultaneously. The correlated response of sexual size dimorphism in each selection regime was compared to the response predicted by four variants of the model, each of which differed only in assumptions about input parameters. Body size responded well to selection, but the correlated response of sexual size dimorphism was weaker than that predicted by any of the variants. Dimorphism decreased in most selection lines, contrary to the model predictions. We suggest that selection on body size acts primarily on growth trajectories. Changes in dimorphism are caused by the fact that male and female growth trajectories are not parallel and termination of growth at different points along the curves results in dimorphism levels that are difficult to predict without detailed knowledge of growth parameters. This may also explain many of the inconsistent results in dimorphism changes seen in earlier selection experiments.

AN ANALYSIS OF SELECTIONAL RESPONSE IN RELATION TO A POPULATION BOTTLENECK.

Selection for increased morphometric shape (ratio of wing length to thorax width) was compared between control (nonbottlenecked) populations and bottlenecked populations founded with two male-female pairs of flies. Contrary to neutral expectation, selectional response was not reduced in bottlenecked populations, and the mean realized heritabilities and additive genetic variances were higher for the bottlenecked lines than for the nonbottlenecked lines. Additive genetic variances based on these realized heritabilities were consistent with independent estimates of genetic variances based on parent-offspring covariances. Joint scaling tests applied to the crosses between selected lines and their controls revealed significant nonadditive components of genetic variance in the ancestor, which were not detected in the crosses involving bottlenecked lines. The nonbottlenecked lines responded principally by changes in one trait or the other (wing length or thorax width) but not in both, and regardless of which trait responded, larger trait size was dominant and epistatic to smaller size. Stabilizing selection for morphometric shape in the ancestor likely molded the genetic architecture to include nonadditive genetic effects.

Association of Increased Cardiothoracic Ratio and Intrauterine Growth Retardation

Clinical observation suggested an association between an increased cardiothoracic ratio (CT) and growth retardation (IUGR) in the premature neonate. To investigate this hypothesis, a case-control study was performed. Study subjects included 23 cases (IUGR) and 55 control (appropriate for gestational age [AGA]) premature infants with birthweights 2000 gm or less; Apgar scores greater than 5 at 5 minutes; no congenital heart disease; no polycythemia; no toxoplasmosis, rubella, cytomegalovirus, or herpes infection. In random order, the first chest radiograph of each infant (less than 24 hours) was reviewed by a single radiologist, unaware of the infant's growth status. The CT ratio was computed after measuring the widest internal width of the bony thorax and the cardiac diameter. Mean birthweight (+/- 1 SD) of the IUGR infants was 1161 +/- 289 g and of AGA infants was 1401 +/- 401 g (p less than 0.002); the mean gestational ages (+/- 1 SD) were 33.2 +/- 2.8 and 30.8 +/- 2.5 weeks (p less than 0.001). Mean CT for IUGR infants was 0.57 +/- 0.07 (+/- 1 SD) versus AGA infants, 0.51 +/- 0.04 (+/- 1 SD), p less than 0.001. When the infants were stratified by growth status and CT ratio, 11 of 23 IUGR and 1 of 55 AGA infants had an increased CT ratio p less than 0.0001. When birthweight and gestational age were covaried, growth status remained the best predictor of CT, p = 0.005. There is a strong association of increased CT and growth retardation in premature infants with birthweights 2000 gm or less.

Fetal kidney screening: growth curves and indices

Kidney size was measured ultrasonographically in a cross-sectional study of 612 foetuses. Values of the length (Nlgs), width (Nqu), thickness (Nap) as well as cross-sectional area (Nqu-Fl) of the kidney were calculated by statistical means and correlated to gestational age. Because of the great biological variance, the ratio of kidney length and width to the thorax width and the ratio of kidney area to the thorax area, was calculated and the standard deviation was found to be very small. The ratios for growth-retarded and macrosomic foetuses from diabetic mothers were examined. The results are discussed and the syndromes, which is often associated with renal abnormality are tabulated.

日本近海のイセエビ属Ｐｈｙｌｌｏｓｏｍａの相対成長

Examination of relative growth of cephalic shield length, cephalic shield width, thorax width and abdomen length to body length revealed the occurrence of six forms of Panulirus phyllosoma, five known and one undescribed, in Japanese waters. These forms were identified as follows: Oshima's form F, which has been proposed as P. japonicus, is identical with this species and includes P. longipes which has close affinity to P. japonicus. Murano's form C is identified as P. penicillatas. Murano's form D and the authors form D' may correspond to P. versicolor and P. ornatus, respectively. Oshima's form E is suggested to be P, homarus. Because of the samall number of specimens and limited information on the morphological characteritics of P. homarus group, the specific identification of forms D, D' and E is tentative. Specific allocation of form B still remains to be investigate. Relative growth seems to be a useful method for the identification and classification of palinurid phyllosoma.

Growth of lung and thorax dimensions during the pubertal growth spurt

In the follow-up study of adolescents residual volume (RV), vital capacity (VC), closing volume (CV), thorax height and thorax width were measured at six month intervals over a six year period; 149 girls and 477 boys, whose ages ranged between 11.5 and 18.5 yr during the follow-up, were investigated. In healthy subjects and in those with respiratory symptoms the rates of change of thoracic dimensions, as calculated by a robust linear regression technique, were moderately well correlated; the growth rates of RV and VC were only slightly correlated, and both were moderately well correlated with changes in thorax dimensions. Thorax height increased relative to thorax width in boys and girls during the follow-up. In boys, thorax height continued to grow, when standing height and thorax width had attained adult values in girls. Thus the thorax attains a more elongated shape. During the adolescent growth spurt the residual volume as a percentage of total lung capacity (RV%TLC) within subjects increased on average 0.6% per yr, and closing volume as a percentage of vital capacity (CV%VC) decreased on average 0.5% per yr. Both of these changes can be accounted for by decreased thorax compliance and increased outward chest recoil at low lung volumes.

Pheromone Traps for Moths: Evaluation of Cone Trap Designs and Design Parameters 1

Cone-orifice traps were found more suitable than sticky traps for capture of 4 moth species with sex attractant lures. Single-cone wind-directional traps were as efficient overall as double-cone fixed traps of similar dimensions. The best orifice diam for capture and retention of 5 species equaled ca. 2× the thorax width of the males; radical departures from this optimum resulted in greatly decreased capture totals. Up to a limiting value trap catches were proportional to the cross-sectional air flow diam of the trap.

The Habitat and Phenetic Variation in Phymata Americana Melin (Heteroptera)

Mason, L. G. (Dept. of Biol. Sciences, State Univ. of New York at Albany, Albany, N.Y. 12203) 1973. The Habitat and Phenetic Variation in Phymata americana Melin. Syst. Zool. 22:271-279.-In natural populations of Phymata americana year-to-year variation in a character measuring shape (i.e., amount of sculpturing of the exoskeleton) is slight or nonexistent in relatively undisturbed habitats similar to those in which the insects have presumably evolved. In areas associated with urbanization and agriculture, substantial (and statistically significant) year-to-year variation occurs. Year-to-year and locality-to-locality variation of thorax width (selected as a size measure) was more complicated, but again variation tended to be less predictable in disturbed than in undisturbed habitats. The interpretation put on these findings is that a stabilization of traits related to fitness (perhaps a more perfect canalization of traits) occurs in habitats to which the populations have become acclimated as regards genetic and developmental processes. Amounts of individual variation did not differ in the two types of habitats. A character chosen to represent the color pattern did not show the differences between habitat-types indicated for structural characters. The possible relationship between this result and the similar phenetic differences between geographically marginal and central populations of another insect species is discussed. [Phymata; habitat; variation.]

Regression of radiological changes in asthma following treatment.

SummaryFirst certain measurements were made from the radiographs of normal children, namely the transverse diameter of the heart, the width of the lower thorax, and the lung length, and from tables pr

Some anthropometric and physiological data in relation to performance of top female gymnasts.

Some anthropological and physiological measurements were taken in 38 competitors of the European championship for female gymnasts in 1967 in Amsterdam. Female top gymnasts were characterized by small height (mean 1.58 m) and weight (mean 52.6 kg). They had extraordinarily small skinfolds, which correlated negatively with their performance. Muscles were well developed and thorax width correlated significantly with the total score.

Some effects of implanted hexoestrol on the growth of steers

1. An experimental test of the effects of 15, 30 and 60 mg. of hexoestrol (ear implants) on growth (over a period of 95 to 98 days) has been carried out in Argentina, using 172 Hereford steers (all 4–5 years old).2. On pasture where the growth rate was only about 0·4 kg. a day, the optimum dose was 30 mg., which gave an extra 0·14 kg. per day.3. The carcasses from the 30 mg. group were significantly heavier by 8 kg., those from the 15 mg. group by 7 kg., but those from the 60 mg. group were only 3 kg. heavier than those from the control group.4. It is suggested that both the poorer response and the lower optimum dose were due to the poorer pastures on which this experiment was carried out.5. Evidence for the carcasses of the treated animals being significantly leaner than the controls was given by the 60 nag. group—the grading was poorer, the excess kidney fat was less, and the subcutaneous fat was thinner.6. Carcass measurements showed differences in the treated groups, but these in general followed the differences in carcass weight.7. Measurements of width of thigh and thorax provided evidence that the depth of carcass had been increased by hexoestrol.8. The incidence of ‘tail raising’ had been increased from 10% in the control group, to 50% and more in the 15, 30 and 60 mg. groups. Carcasses from such animals had a slightly greater width at the thigh.9. The existence of an optimum dose is not thought to be due to restlessness, as indicated by ‘tail raising’, but to a depressant action of hexoestrol on growth. In this connexion, data on the weights of the kidneys show that the 60 mg. dose decreases kidney weight (and implicitly the level of protein metabolism) to the value of the control.10. Evidence was obtained of a rapid change in live weight when the steers were without food. During a single morning this was, on the average, about 13 kg. per animal, followed by a further 25 kg. during the subsequent 24 hr. (see Appendix II).