Intelligence and educational level in relation to body mass index of adult males.

In this study we explore the relationships between intelligence test score, educational level, and degree of body fatness. We collected data on intelligence test score, educational level, height, and weight from a sample of 26,274 young Danish men and computed body mass index (weight/height2) as a measure of fatness. Both intelligence test score and educational level had maximum values below the median for body mass index and declined monotonically thereafter. The decline was equal for test score and educational level and above 32 kg/m2 corresponded to almost half a standard deviation. These results are not readily explained by stigmatization of frank obesity, and other mechanisms, possibly genetic, may be responsible.     

Women's height,reproductive success and the evolution of sexual dimorphism in modern humans

Recent studies have shown that, in contemporary populations, tall men have greater reproductive success than shorter men. This appears to be due to their greater ability to attract mates. To our knowledge, no comparable results have yet been reported for women. This study used data from Britain's National Child Development Study to examine the life histories of a nationally representative group of women. Height was weakly but significantly related to reproductive success. The relationship was U-shaped, with deficits at the extremes of height. This pattern was largely due to poor health among extremely tall and extremely short women. However, the maximum reproductive success was found below the mean height for women. Thus, selection appears to be sexually disruptive in this population, favouring tall men and short women. Over evolutionary time, such a situation tends to maintain sexual dimorphism. Men do not use stature as a positive mate-choice criterion as women do. It is argued that there is good evolutionary reason for this, because men are orientated towards cues of fertility, and female height, being positively related to age of sexual maturity, is not such a cue.     

Stable fly (Stomoxys calcitrans: Diptera, Muscidae) trap response to changes in effective trap height caused by growing vegetation

Stable flies (Stomoxys calcitrans L.) are blood-feeding pests of cattle, whose populations are often monitored using sticky traps. Trap responses at different heights were compared with: 1) a choice and no-choice test, with sticky cards set at 30 and 121 cm heights (above ground), and 2) tall (120 cm) traps placed in short (3 cm) and tall (40 cm) grass to assess how vegetation height affects trap catches. In the first experiment, the percentage of upper to lower trap catches were similar at choice (16%) and no-choice traps (15%). In the vegetation study, stable fly catch height data were fitted to gamma distributions to determine the most productive trap heights; 20 cm above short grass and 24 cm above tall grass (from lower edge of trap). The results indicate that traps used to monitor stable fly populations should be maintained at a constant distance above surrounding vegetation rather than ground surface, otherwise trap data can be misleading.     

The relative effectiveness of teaching methods on pupils' understanding of the classification of living organisms at two levels of intelligence

A classification task, involving the sorting of pictures of plants and animals into major orders and classes, and a standardised test of general intelligence, were administered to randomly selected groups of 12 year old pupils drawn from four comprehensive schools. Sub-samples were selected at random of pupils of above and below average intelligence who had been taught classification either by the “Nuffield” approach or by a “traditional” method. Analysis of variance of the scores obtained showed that although the achievement of the upper intelligence group was superior (1 %level) to that of the lower intelligence group, there was a significant interaction (5 % level) between the method of teaching that had been received and intellectual level. Pupils of above average intelligence generally obtained higher scores when they had been taught by the “Nuffield” method, whereas the achievement of pupils of below average intelligence was generally much greater when they had been taught by a “traditional” method.     

Body mass index and nutritional status of the Bayash Roma from eastern Croatia

This study examines anthropometrically assessed nutritional status of the Bayash, the Roma population from the eastern Croatian region of Baranya, and compares it to the non-Roma general population of eastern Croatia. The analysis of nutritional status and diets is a segment of multidisciplinary anthropological and epidemiological survey of the Roma minority population in Croatia began in 2005. The Bayash are an ethnic group that arrived to Croatia from Romania most likely in the 19th century and speaks a distinct archaic dialect of the Romanian language. The Roma population of Baranya approximates 1,000 according to the 2001 census. The Bayash sample comprised 227 adults aged 18-65yrs. The women fall below the Croatian 10th percentile for stature and men track about the 10th percentile. Both sexes approximate the 25th percentile for body weight. Despite their diminutive size, the Bayash appear to have adequate nutritional status until the age of 35yrs after which their average BMI exceeds the value of 25 kg/m(2) and falls in the overweight category. However, 8% of Bayash are underweight (BMI<18.5) in contrast to 1% of the majority population in the region. Underweight rates are especially high in women (11%) compared to men (4%). The prevalence of overweight (BMI 25.0 to 29.9) of 30% is considerably lower than in the majority population (42%) while the prevalence of obesity (BMI>or=30.0) of 23% is approximately equal. Overall unsatisfactory nutritional status of the Bayash merits attention. It appears to be the product of unhealthy dietary habits and their socio-economic deprivation that resulted from their poor education and extremely high unemployment.     

Growth and yield of six short varieties of spring wheat derived from Norin 10 and of two European varieties

Five short varieties of spring wheat derived from Norin 10: Lerma Rojo 64A (R), Penjamo 62 (P), Sonora 64 (S), Mexico 120 (M), and an unnamed selection obtained from Mexico (X), had grain yields equal to, or only slightly less than those of the taller European spring varieties Kloka (K) and Jufy I (J). Yields ranged from 500 to 580 g/m² of dry matter. The short variety NBJ115 (N) was severely infected with yellow rust and yielded only 290 g/m². Total dry weight (excluding roots) of the short varieties was less than of J and K; hence grain accounted for 49 % of the total for the short varieties and 42 % for J and K. Most of the short varieties had fewer ears than the tall ones because sowing difficulties and poor germination produced fewer plants. The relative yields of X, P, R and S seemed to be correlated with their plant and ear densities. Leaf area duration after flowering (D), based either on total green area or on green area above the flag-leaf node only, was less for the short varieties than for J and K. The apparent mean efficiency of this area in grain production (grain yield divided by D) was 50% greater for the short than for the tall varieties. The height of the short varieties ranged from 43 cm (M) to 79 cm (N). K was 92 cm and J 97 cm tall. Differences in height depended on the lengths of the top four internodes and not on number of internodes. Main shoots of all varieties produced seven or eight leaves. All varieties initiated spikelets 45–48 days after sowing. The short varieties flowered 103 days and matured 155 days after sowing; J and K flowered and matured about 1 week earlier.     

Reported versus measured adult statures

Reported and measured statures were obtained for 100 husband-wife pairs. In addition, wives were asked to specify whether their husbands were tall, medium, or short. Correlations between reported and measured statures are high (0.84–0.97) and wives tend to overestimate their own measured stature by about 1 cm, and that of their husbands by about 1.3 cm. Wives correctly classify their husbands as tall, medium, or short in about 70% of the cases, using terciles of the stature distribution of American men as the standard. Reported statures may be useful proxies for measured statures for certain purposes. In the absence of measured or reported statures, a wife's categorization of her husband as tall, medium, or short may be satisfactory for some group studies.     

Normal intellectual development in children born from women with hypothyroxinemia during their pregnancy

Proper maternal thyroid function is known to be essential for neural differentiation and migration in the fetus during the first half of pregnancy. The objectives of this study were to assess the relationship between thyroxin levels, in pregnant women with no thyroid disease and the intellectual development of their offspring in a non-iodine-deficient area, and to know specifically whether or not isolated hypothyroxinemia during pregnancy was associated with a lower intelligence in the offspring.Previously we had publicated values TSH, FT4, free T3 (FT3), anti-thyroid peroxidase antibodies (TPO Abs) and urinary iodine concentration (UIC) in 1322 pregnant women in our hospital area. Now we presented results of intelligence quotient in children born from these pregnancies. We assessed 455 children at one year of age using Brunet-Lezine scale. Of these, 289 children were evaluated again at 6–8 years of age using the WISC-IV. From the total group of children recruited, we established as control subgroup, children born of rigorously normal pregnancies (women with UIC > 150 μg/L, FT4 > 10th percentile and TPO-Ab negative in both trimesters). The remaining children were divided into two subgroups: those born to mothers with FT4 below the 10th percentile and the rest. No correlation was found between FT4 maternal levels, in either of trimesters studied, and the intellectual scores of offspring. No differences were found in intellectual scores comparing children born to mothers with hypothyroxinemia and those whose mothers were euthyroxinemic in both trimesters, or with the control subgroup.As conclusions we did not find any association between the levels of maternal FT4 during pregnancy and the subsequent intellectual development the offspring from these pregnancies. We attribute this result to the fact that all the pregnant women included had normal thyroid function.     

Pseudoachondroplasia with cerebral and renal cysts

Pseudoachondroplasia (PSACH) is a spondylo-epi-metaphyseal dysplasia characterised by disproportionate short stature, generalised ligamentous laxity and precocious osteoarthritis. Autosomal dominant inheritance has been demonstrated in many families. The present case was normal at birth. By 3 years of age his height has fallen below the 5th percentile. At 6 1/2 years of age he was 99 cm tall (-3.5 SD), and he had bowing of the lower extremities and some limitations of movements at the elbows and knees. Radiographs showed features of PSACH. Kypho-scoliosis appeared later on with anterior beaking of the vertebrae. Cerebral CT scan showed a very large frontal cyst communicating with the IIIrd ventricle. RMI confirmed the frontal cyst and showed dilatation of the IIIrd ventricle and of the occipital horns of the lateral ventricles, and a right frontal parietal hemispheric atrophy. At 26 years of age he complained of pain in the knees, swallowing difficulties, and vertigo. Renal ultrasonographic examination showed a large cortical cyst of the right kidney and smaller cysts in both kidney.     

Seasonal and vertical demography of dead portions of shoots of smooth cordgrass in a south-temperate saltmarsh

Knowledge of the crop-size and vertical profile with respect to sea level of dead leaf blades and other shoot parts of saltmarsh grasses is a prerequisite for projections of seawater impact upon saltmarsh grass-shoot decomposers. We measured seasonal changes in quantities of leaf blade and leaf sheath+stem of smooth cordgrass in southern temperate saltmarshes of three types: low- (LD), mid- (MD), and high-drainage (HD) marshes (i.e., with low to high densities of drainage creeks). In each type of marsh, we took samples in the three characteristic subsites, short-shoot, intermediate-height, and tall-shoot. Wholly dead (brown) and living (some green) shoots were counted and their canopy heights measured, and the mass of all shoots was measured in 10-cm height increments (above sediment), with separation of living and dead parts. Detached material was also quantified, separated into that trapped in the canopy, and that prostrate on the sediment. Extent of marsh drainage did not affect the density of wholly dead shoots, which ranged from an average of 51 m⁻² in autumn to 103 m⁻² in spring, and 57 m⁻² in tall subsites to 89–96 m⁻² in short and intermediate subsites. The top of the dead-shoot canopy was about 20 cm taller than the living-shoot canopy in winter/spring, but was below it ( ≈50 cm) in summer/autumn. The mass of standing-dead leaf blades was 4- to 5-fold greater in winter than in summer, and it was about 2.5-fold greater at tall than at short sites. Detached litter trapped among shoots above the sediment averaged 26% of total dead-shoot mass, but litter lying on the sediment averaged only 6% of total dead-shoot mass. Since export of macrodetritus from marshgrass stands is inconsequential, the small prostrate-litter mass implies that breakdown of shoots to small particles takes place within the vegetated marsh, and that standing decay predisposes fallen material to rapid disintegration. Comparison of heights of usual tidal contact on shoots at the short- and tall-shoot subsites showed that projected impacts of seawater upon leaf-blade decay would be greater at short-shoot subsites (high marsh) than at tall-shoot subsites (low marsh). This was because the vertical profile of dead-blade mass resulted in more of the short-shoot dead-blade mass residing within the vertical span most regularly contacted by flooding tides.     

RELEVANCE OF REGRESSION TO THE MEAN TO EPIDEMIOLOGICAL AND CLINCAL STUDIES: A REVIEW OF THE LITERATURE

Investigation of the relative heights of pairs of fathers and sons led the famous 19th century scientist, Sir Francis Galton, to the concept known as "regression to the mean." Gallon observed that sons of extremely tall or extremely short fathers tended to be less extremely tall or short. The concept has since been - found to apply to virtually any experiment requiring a test-retest design. On the average, the bottom group on the first test will tend to increase, and the top group will on average decrease on the retest. For example, a clinical study requiring an initially high blood pressure baseline value (screening value), might decrease as a group on a subsequent retest, perhaps merely due to a regression effect. One way to account for possible bias due to regression effects is by using an appropriate control group. In the absence of a control group, James (1973) has developed some useful formulas for estimating the expected regression effect, when a truncated population is being sampled. Choice of an appropriate baseline value should also be guided by consideration of the potential effects of regression.     

Localization of the pituitary lactotropes and thyrotropes within Ambystoma gracile by histochemical and immunochemical methods

Summary The prolactin-producing cells are the first hormone-producing cells of the pars distalis to be differentiated within Ambystoma gracile. They first appear when the larvae attain a length of approximately 3.0 cm snout to vent length (SVL). Thyrotropes are observed as the next chromophilic cells to appear, and they occur when the larvae are approximately 4.5 cm SVL. Both thyrotropes and lactotropes increase in numbers until metamorphosis. Gonadotropes begin to appear when larvae attain a size of 5.0 cm SVL and become extremely abundant when larvae are in excess of 7.0 cm SVL. Animals, generally, exhibit the greatest number of thyrotropes just prior to the mean size for metamorphosis, and metamorphosing animals exhibit a dramatic reduction in the number of thyrotropes. Neotenous larvae have an abundant number of thyrotropes which are mainly located along the caudal periphery of the pituitary.     

Influence of a propeller on Saccharomyces cerevisiae fermentations in a pilot scale airlift bioreactor

The hydrodynamics (sectional gas holdup and liquid velocities) and oxygen transfer performance of a conventionally operated multiconfigurable pilot scale (0.25?m³) concentric airlift bioreactor containing baker's yeast were significantly improved by operating a marine propeller to draw liquid down the draft tube and aid recirculation at the base of the vessel. Propeller operation reduced the severe DOT heterogeneity of the reactor, which gave DOT values below 1% air saturation in the riser, by producing DOTs above 40% around the vessel at maximum energy dissipation rate. As a consequence the overall oxygen uptake rate (OUR) of the baker's yeast increased up to 3 fold with the total energy dissipation rate into the reactor until the lowest DOTs of the vessel were at or above 10%. The different degrees of heterogeneity generated by the two reactor configurations enabled the reactor to be used as a scale down tool to study the impact of heterogeneity on the physiology of fermentation broths. Comparison of the hydrodynamics and oxygen transfer between tall and short reactor heights revealed that the faster circulation times of the short reactor produced a greater improvement in the OUR with propeller operation even though similar DOT changes occurred around both sizes of reactor. This indicated that the yeast cells were responding to the rapid DOT changes around the vessel.     

Influence of sward structure on daily intake and foraging behaviour by horses

The spatial heterogeneity of grasslands determines the abundance and quality of food resources for grazing animals. As plants mature, they increase in mass, which allows greater instantaneous intake rates, but the cell wall concentrations increase too, reducing diet quality. In ruminants, daily intake rates are often constrained by the time needed for the ingesta to pass through the rumen, which is influenced by the rate of digestion. It has been suggested that the digestive constraint should have much less effect on hindgut fermenters such as equids. Horses play an increasing role in the management of grasslands in Europe, but the data on the influence of the heterogeneity of the vegetation on their daily intake and foraging behaviour are sparse. We report here the results of a preliminary study concerning the effects of sward structure on nutrient assimilation and the use of patches of different heights by horses grazing successively a short immature, a tall mature and a heterogeneous pastures (with short and tall swards). Daily nutrient assimilation was higher in the heterogeneous pasture compared to the short (+35%) and the tall (+55%) ones. The digestive constraints may have limited voluntary intake by horses on the tall swards. In the heterogeneous pasture, the mean height used for feeding (6 to 7 cm) by horses was intermediate between the heights used in the short (4 to 5 cm) and tall pastures (22 to 23 cm), and the animals may thus have benefited from both short swards of high quality and tall swards offering a higher instantaneous intake rate.     

Comparison of hair, nails and urine for biological monitoring of low level inorganic mercury exposure in dental workers.

Creatinine-corrected urine mercury measurements in spot urine samples are routinely used in monitoring workers exposed to inorganic mercury. However, mercury measurement in other non-invasive biological material has been used in some epidemiological studies. Dentists and dental nurses remain a group of workers with potential exposure to inorganic mercury through their handling of mercury-containing amalgam, although changes in work practices have reduced the current, likely exposure to mercury. Therefore, dental workers remain an occupational cohort in whom the value of using different biological media to identify exposure to low level inorganic mercury can be investigated. Samples of head hair, pubic hair, fingernails, toenails and urine were analysed for mercury content from a cohort of UK dentists (n=167) and a socioeconomically similar reference population (n=68) in whom any mercury exposure was primarily through diet. The mercury content in all biological material was significantly higher in the dental workers than in the control population (p<0.0001). The geometric mean and 90th percentile mercury concentrations in the urine samples from dentists were 1.7 and 7.3 micromol mol(-1) creatinine, respectively, with only one sample having a value at around the UK's Health and Safety Executive biological monitoring health guidance level of 20 micromol mol(-1) creatinine. Receiver operator characteristic analyses suggested that the ability of the biological material to discriminate between dentists and referents were fingernails>urine approximately equal to toenails>pubic hair approximately equal to head hair. Further investigation is warranted as to why fingernails appear to be such a good discriminator, possibly reflecting some contribution of direct finger contact with amalgam or contaminated surfaces rather than systemic incorporation of mercury into growing nails. Good correlation between head hair and pubic hair mercury levels in all subjects was obtained (r=0.832), which was significantly improved when hair samples weighing <10 mg were excluded (r=0.868). Therefore, under these exposure conditions and using the described pre-analytical washing steps, there is little influence from atmospheric contamination on the level of mercury content of head hair. The choice of non-invasive biological materials for mercury analysis depends on a number of considerations. These include the toxicokinetics of urinary mercury excretion, the growth rates of hair and nail, the nature and time-frame of exposure, and the fact that urine mercury may not reflect the body burden level from dietary methyl mercury. However, the data from this study suggests that urine mercury remains the most practical and sensitive means of monitoring low level occupational exposure to inorganic mercury.     

Dioxygen solubility in aqueous phosphatidylcholine dispersions

The solubility of molecular oxygen, or dioxygen, in low weight percent (1.5%) sonicated dimyristoylphosphatidylcholine (DMPC) aqueous dispersions saturated with air has been measured as a function of temperature between 10 degrees C and 40 degrees C. A modified Winkler technique was used involving a dual cell coulometric titration with voltammetric endpoint detection in a mixed solvent (methanol/water). The results indicate that dioxygen is approximately four times more soluble in the liquid crystalline bilayers (above 24 degrees C) than in the gel state bilayers (below 24 degrees C). The solubility of dioxygen in the bilayer does not appear to be strongly temperature dependent on either side of the 24 degrees C phase transition. The dioxygen solubility in gel state DMPC is approximately equal to that in water at the same temperature. Our result are contrasted with recent measurements made using EPR spin labels.     

Mutagenicity of coolwhite fluorescent light for Salmonella

The most common fluorescent lamps in use today in homes and businesses in the United States, 'coolwhite' fluorescent lamps, emit light that is mutagenic for Salmonella. Strains that carry both a uvrB mutation and plasmid pKM101 are extremely susceptible to this light-induced mutation. Both base substitution and frameshift mutations can be induced without substantial lethal effects on the bacteria. Induced mutations accumulate essentially as a linear function of the time bacteria are exposed to illumination. Of Salmonella histidine-requiring strains with known nucleotide target sequences (Hartman et al., 1986; Cebula and Koch, 1989, 1990), strains either carrying one of the base substitution mutations, hisG428 and hisG46, or one of the frameshifts, hisC3076 and hisD6610, are most highly mutagenized whereas frameshift strains with hisD6580 and hisD3052 exhibit lower rates of mutagenesis. Mutagenicity does not appear to require the presence of oxygen. A filter blocking wavelengths below 370 nm eliminates mutagenesis. Polystyrene, cellulose acetate and, especially, mylar and glass filters reduce mutagenesis, indicating that at least some of the mutagenic effects can be attributed to leakage of radiations below 290 nm (far-ultraviolet light) from 'coolwhite' lamps. The more recently introduced fluorescent 'softwhite' lamps are roughly 10-fold less mutagenic at approximately equal light intensity. Incandescent light bulbs are much less mutagenic than are these fluorescent lamps. Our mutational data correlate closely with previous results in eukaryotic cells (Jacobson and Krell, 1982). A uvrB recA Salmonella double mutant is hypersensitive to the lethal effects of coolwhite fluorescent light, even when illuminated through the lids of glass Petri dishes. Thus, appropriate Salmonella strains would appear to be simple and useful screens for both the mutagenic and the lethal activities of fluorescent lamps. These systems are amenable to classroom laboratory use as relatively safe and effective means of demonstrating environmental mutagenesis.     

Diagnostic efficacy of screening tests for hereditary hemochromatosis.

Hereditary hemochromatosis is transmitted as an autosomal recessive trait. Analyses of pedigrees suggest that the frequency of disease (proportion of homozygous individuals) in the general population is approximately 0.3% and that approximately 11% of the population are heterozygous. The genotype of 194 persons in 38 pedigrees was determined by HLA-A and HLA-B haplotyping. Likelihood analysis was then used to appraise the transferrin saturation test when used alone and in combination with the serum ferritin test to detect homozygosity and heterozygosity in these pedigrees. A single cut-off point of 55% for transferrin saturation and a cut-off point at the 90th percentile for the serum ferritin level were adequate for the detection of hemochromatosis if homozygosity was considered to be present when the results of one or both tests were positive. To further assess the value of the transferrin saturation test the percentages were stratified into five intervals. A percentage transferrin saturation of 75 or greater and a serum ferritin level above the 90th percentile ruled in homozygosity, whereas a percentage transferrin saturation of less than 55 and a serum ferritin level at or below the 90th percentile ruled it out with confidence. The probability of heterozygosity rose to 90% when the percentage transferrin saturation was between 35 and 55 and the serum ferritin level was at or below the 90th percentile. The use of five cut-off points allowed the probability of homozygosity and heterozygosity in a pedigree to be estimated for all values of transferrin saturation. Although these screening tests are not recommended for use in the general population, they may be worth while in selected groups of patients.     

Water potential gradients of tall and short cultivars of winter wheat

Summary Water and osmotic potentials were measured with thermocouple psychrometers, weekly after heading, two times each day at pre-dawn and at noon, in flag leaves and grain of tall and short cultivars of winter wheat grown in the field under rain-fed conditions.Water was held with less tension in the grain than in the leaf for both tall and short cultivars. The tall cultivars had lower leaf water potentials, but higher grain water potentials, than the short cultivars. The grain osmotic potential was lower in the short cultivars compared to the tall ones. Grain yield of short cultivars (1810 kg/ha) was more than that of tall cultivars (1730 kg/ha). Apparently higher leaf water potentials of short cultivars enabled more photosynthates to move into the grain.