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Parents may respond in various ways to the birth of a seriously affected child. They may, for example, decide not to have any more children or to have one more child and then stop. These various responses are called "stoppage rules" in the genetic literature. Where stoppage rules are operative, the order in which affected and nonaffected children are born is disturbed in definite ways. The present paper shows that stoppage rules are at work in a recently reported data set consisting of 46 multiplex families of childhood autism and, as a consequence, that the segregation ratio was underestimated in the original report. The implications of these results for genetic studies of autism are then discussed.

Men alcoholics entered the work force at a low socioeconomic level and though their status gradually increased, it never reached their fathers' or their brothers' level. Downward mobility in relation to significant others seems to play a role in the etiology of alcoholism.

The circular dichroism spectra of eleven double-stranded DNAs, five natural with known nearest neighbor frequencies and six synthetic polydimers and polytrimers, were measured from 210 to 310 nm in the absence and presence of increasing amounts of actinomycin up to saturation. Based on the fact that the circular dichroism of nucleic acids is a nearest-neighbor frequency-dependent property, matrix analysis of the problem revealed which neighbor sets were perturbed by actinomycin, presumably by intercalation of the planar moiety of the molecule. The intercalation sites can be separated into three families. The first-neighbor units GpC and CpG are very favorable binding sites for actinomycin. ApG, CpC, ApC, TpC, and TpG appear to be less attractive sites, while ApT, TpA, and ApA are unfavorable sites.

Subterranean clover (Trifolium subterraneum L. cv Woogenellup) and soft chess grass (Bromus mollis L. cv Blando) were grown in monocultures with (15)NH(4)Cl added to the soil to study nitrogen movement during regrowth following shoot removal. Four clipping treatments were imposed. Essentially all available (15)N was assimilated from the soil prior to the first shoot harvest. Measurements of total reduced nitrogen and (15)N contained within that nitrogen fraction in roots, crowns, and shoots at each harvest showed large, significant (P

The behavior of interest in this study was participation or non-participation in a non-school skill-development program carried out in Ottawa, Ontario, for children living in a rent-to-income housing complex. Participant and non-participant children differed sharply only in sibship size; the larger the sibship from which a child came the greater the probability that he or she would participate. The basis for this relationship seems to have been a strong tendency for the probability of a child's participating to increase whenever a brother or sister in the same family participated.

11 tests were selected from two microcomputer-based performance test batteries because previously these tests exhibited rapid stability (less than 10 min, of practice) and high retest reliability efficiencies (r greater than 0.707 for each 3 min. of testing). The battery was administered three times to each of 108 college students (48 men and 60 women) and a factor analysis was performed. Two of the three identified factors appear to be related to information processing ("encoding" and "throughput/decoding"), and the third named an "output/speed" factor. The spatial, memory, and verbal tests loaded on the "encoding" factor and included Grammatical Reasoning, Pattern Comparison, Continuous Recall, and Matrix Rotation. The "throughput/decoding" tests included perceptual/numerical tests like Math Processing, Code Substitution, and Pattern Comparison. The output speed factor was identified by Tapping and Reaction Time tests. The Wonderlic Personnel Test was group administered before the first and after the last administration of the performance tests. The multiple Rs in the total sample between combined Wonderlic as a criterion and less than 5 min. of microcomputer testing on Grammatical Reasoning and Math Processing as predictors ranged between 0.41 and 0.52 on the three test administrations. Based on these results, the authors recommend a core battery which, if time permits, would consist of two tests from each factor. Such a battery is now known to permit stable, reliable, and efficient assessment.

A 500 MHz 1H-NMR study on a synthetic DNA pentadecamer comprising the specific target site of the cAMP receptor protein in the ara BAD operon is presented. Using pre-steady state NOE measurements, unambiguous assignments of all the imino proton resonances and associated adenine (H2) resonances are obtained. From the NOE data interbase pair interproton distances involving the imino and adenine (H2) protons are determined. It is shown that these distances are very similar to those expected for classical B DNA (RMS difference of 0.5 A), but are significantly different from those expected for classical A DNA (RMS difference of 1.1 A).

Preeclampsia/eclampsia, also known as toxemia of pregnancy, remains one of the great triad of obstetric complications. The outlook for the preeclamptic woman and the fetus has improved as a result of increased knowledge of uteroplacental-fetal physiology and of the physiologic deviations involved in preeclampsia, although the basic cause of preeclampsia remains unknown. Careful screening of women at risk for preeclampsia along with early detection and treatment can help reduce the toll taken in stillbirths, prematurity, and maternal death. Current concepts of pathophysiology are reviewed as is nursing care during the antepartum and intrapartum periods.

Eleven members of a large Finnish family from Astoria, Oregon were studied because of an erythrocytosis. No abnormality was detected by the usual hemoglobin electrophoretic tests, but an abnormal variant was separated by reverse phase HPLC. All of the affected individuals have an increased oxygen affinity with a P50 for whole blood at 37 degrees C averaging 18 torr. Fifty percent of their hemoglobin was found to have a threonyl residue in place of the normal prolyl residue at position 36 (C2) of the beta globin chain. This abnormality is identical to Hb Linkoping which was recently reported in a Finnish man living in Sweden.

Erythrocyte 2,3-diphosphoglycerate levels are determined principally by a single molecule which has both diphosphoglycerate mutase (DPGM) and diphosphoglycerate phosphatase activities. An antiserum containing precipitating antibodies against this molecule was used to measure its amount in red cells from normal controls, from subjects with hypothyroidism or hyperthyroidism, and from a Japanese proband who has hemolytic anemia attributed to heterozygosity for a genetic variant. The amount of DPGM in normal adult erythrocytes is 0.98 +/- 0.014 mg/gm Hb. Slightly increased amounts are found in normal cord blood and in subjects with hyperthyroidism. Hypothyroid subjects have a significantly decreased concentration of DPGM, 0.82 +/- 0.06 mg/gm Hb. Restoration of euthyroid status during treatment results in a return of DPGM amounts to normal. The red cells of the Japanese subject contained 0.67 mg/gm Hb of DPGM as measured by immunoprecipitation.

Photosynthesis and transpiration was measured in the large emergent C 4 sedge Cyperus papyrus (papyrus) which occupies wide areas of wetland on the African continent. The maximum observed value of net assimilation was 35 μmol CO 2 m -2 s -1 at full sunlight but light saturation of photosynthesis did not occur. The quantum yield of photosynthesis obtained from the initial slope of the light response curves (0.06 mol mol -1 incident light) was relatively high and close to previously recorded values for some C 4 grasses. Measurements made over two days showed that stomatal conductance was sensitive to the ambient air vapour pressure deficit (VPD) and was consistently lower on the day when VPD's were higher. There was, however, no marked midday closure of the stomata. Photosynthesis was also reduced on the day when VPD's were higher. The relationship between net photosynthesis and stomatal conductance was close to linear over the range of measurement conditions, with the result that intercellular CO 2 concentrations (C i ) did not vary markedly. There was some evidence that C i decreased at high VPD's. The regulation of stomatal movement in papyrus appears to minimise excessive water loss while not severely limiting photosynthesis. The significance of this strategy for a wetland species with plentiful supplies of water is discussed.

PALS (for "participate and learn skills") was a nonschool skill-development program offered to all children 5-15 years of age living in a publicly supported housing complex in Ottawa, Ontario. While participation was excellent, none but marginal and possibly nonexistent spillover effects on school performance or behavior in the home were observed. However, clear and statistically significant changes occurred on unobtrusive measures of antisocial behavior outside home and school. A cost-benefit analysis indicated that potential savings, primarily in reduced vandalism but also in reduced police and fire costs, greatly exceeded the cost of mounting the program.

Many genetic diseases shorten the lives of people who have them. Hence, it makes sense to speak of years of life lost due to cystic fibrosis or sickle-cell anemia or numerous other genetic disorders. In conventional practice, years of life lost is calculated for causes of death only, but a genetic disease is better understood as a risk-altering state or condition: it acts not at the time of death only but from birth onwards. Therefore, we must reformulate the concept of years of life lost before applying it to genetic conditions. This has already been done for congenital genetic diseases. This paper extends the reformulation to diseases with delayed onset. Huntington disease (HD) is used as an example.

Work at the Naval Biodynamics Laboratory aims at developing a battery of performance evaluation tests for environmental research (PETER). Because repeated-measures designs are virtually universal in environmental studies, the paradigm focuses on stabilisation with practice; thus far, over 50 tasks have been studied. The present report describes how five computerized video games fare as performance tests. The tasks were performed for 3 weeks each, in the same order, by the same subjects. The results show that four out of the five games meet all criteria satisfactorily and one does not, a favorable showing for the video games in comparison with conventional tests of either the paper-and-pencil or apparatus types. In terms of availability, equipment reliability, expense, and other practical considerations, the video games have many advantages. It is concluded that video games have considerable promise for performance testing and other applied contexts.

A congenital genetic condition does not act either as a cause of death or at the time of death only. Hence, years of life lost through such a conditon cannot be calculated in the same way as for a conventional cause of death. The main difference is that a cause of death acting at age x cuts off as many years of life as the dead person might otherwise have expected to live (life expectancy at age x), whereas a congenital genetic condition exposes an affected person to a different schedule of life-threatening risks from birth onwards. In the latter case, years of life lost is calculated as the difference in life expectancy at birth for affected and non-affected persons. This reasoning is worked out in algebraic form and then applied to Down's syndrome. The data base is provided by two large and recent studies, one in Massachusetts and the other in Denmark, of mortality rates among all cases of Down's syndrome, whether in an institution or not, born during a given period of years or living at a given point in time in a fixed geographical area. So calculated, years of life lost through Down's syndrome relative to the United States general population in 1970 was 53.6 years per 1000 livebirths. Prenatal mortality is also discussed.

Detached shoots of Bryophyllum fedtschenkoi maintained in a closed system in the light exhibited an endogenous circadian rhythm in CO2 compensation. The rhythm was sensitive to changes in light intensity and temperature. At 15° C it damped rapidly in light of 78 J m(-2) s(-1), but at 10° C a rhythm of considerable amplitude was evident at this same light intensity. During the transient (i.e. the temporary state of the rhythm before it acquired its steady state) low compensation values between 0 and 5 ppm CO2 were achieved. When the plants were maintained at a higher light intensity prior to the measurements, the period of low compensation during the transient was extended, and zero values were obtained under some conditions.Studies of gas exchange at opposite phases of the rhythm revealed: (i) that the rate of uptake of (14)CO2 differed, both in light and darkness (the epidermis was removed during these observations to avoid interference from stomatal rhythms); (ii) 'photorespiration', estimated by extrapolation of the graph relating photosynthetic rate and CO2 concentration, was highest during the peaks of the rhythm in CO2 compensation; (iii) estimates of the capacity for 'photorespiration' by the glycine-1-(14)C assay indicated highest values during the troughs of the rhythm. These findings are discussed in relation to the C4-acid metabolism of this species. Low CO2 compensation is probably due to the activity of phosphoenolpyruvate carboxylase and not to the absence of processes involving CO2 evolution.

The effects of essential oils isolated from Douglas fir needles on sheep and deer rumen microbial activity were tested by use of an anaerobic manometric technique. Rumen microorganisms were obtained from a sheep which had been fed mainly on alfalfa hay and dried range grass. One deer used in this study had access to Douglas fir trees the year around, whereas the other deer had no access to Douglas fir. All of the monoterpene hydrocarbons isolated from Douglas fir needles-alpha-pinene, beta-pinene, limonene, myrcene, camphene, Delta(3)-carene, and terpinolene-promoted only slightly or had no effect on deer rumen microbial activity, whereas all of them promoted activity in sheep rumen microbes, except Delta(3)-carene and terpinolene, which inhibited activity. Of the oxygenated monoterpenes, all monoterpene alcohols-alpha-terpineol, terpinen-4-ol, linalool, citronellol, and fenchyl alcohol-strongly inhibited the rumen microbial activity of both sheep and deer. Monoterpene esters (bornyl acetate) produced mild inhibition for both sheep and deer microbes, and citronellyl acetate inhibited rumen microbial activity in sheep, whereas it promoted activity in both deer. Monoterpene aldehyde (citronellal) inhibited the activity of rumen microbes from both sheep and deer having no access to Douglas fir from the Hopland Field Station, whereas they produced no effect upon the deer having access to Douglas fir from the Masonite forest. Rumen microbial activity for sheep and deer was promoted slightly with aliphatic ester (ethyl-n-caproate). There was a marked difference between sheep and deer rumen microbes as affected by addition of the various essential oils. The monoterpene hydrocarbons promoted activity more on sheep rumen microbes than on deer, and the monoterpene alcohols inhibited sheep rumen microbial activity more than that of deer. Furthermore, the deer rumen microbes from Hopland Field Station were affected more than the deer from Masonite forest.

Eight groups of 40 basic airmen each worked the Manual Crank for an initial period of 5 min., rested, and then worked for a final period of 3 min. The eight groups were distinguished according to the load (heavy or light) against which they worked in the two periods and the rest interval (30 sec. or 4 min.) between them. Response was scored in revolutions of the crank handle in each 20 sec. interval (trial). None of the main effects had any bearing on the intertrial correlations within or between the periods of cranking. The results lend further support to the proposition that intertrial correlations are invariant under rest interval (distribution of practice) and the force required to make a response.

Lever positioning is a simple motor task, one of a very few, in which the intertrial correlations do not ordinarily show strong superdiagonal patterning. However, if knowledge of results (KR) is withheld, superdiagonal pattern appears. If KR is given every 3rd, 4th, or 10th trial, superdiagonal pattern appears in blocks of trials without KR. The pattern is strongest in the first block of trials without KR and in gradually weakening strength in subsequent blocks. It appears, therefore, that in lever-positioning an inverse relation holds between learning and superdiagonal pattern. In proportion as learning progresses (because KR is given) superdiagonal pattern degenerates. When KR is given after every trial, the pattern is vestigial at best. These results are attributed to the terminal effects of practice in a very simple task.