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Of 45 diabetic pregnancies, 80% were Class C, D, or R. The perinatal mortality rate was 4.4% (corrected 2.2%); however, neonatal morbidity was high. Of the infants, 28% developed respiratory distress syndrome (RDS); 18%, asphyxia; and 42%, hypoglycemia. Thus, the woman with overt diabetes needs delivery in an institution where neonatal expertise and modern neonatal facilities exist. Of the mothers 28% had a family history that was negative for diabetes mellitus. Four neonates developed RDS despite mature lecithin/sphingomyelin ratios.

In this paper, we enumerate the (nonisomorphic) Steiner triple systems of order 19 which contain a subsystem of order 9. The number of these designs is precisely 284457. We also determine which of these designs also contain at least one subsystem of order 7, and how many. Exactly 13529 of them contain at least one subsystem of order 7.

A strong starter (of order n) in an additive Abelian group Gof odd order $n = 2t + 1$ is a set $S = \{ \{ x_1 ,y_1 \}, \{ x_2 ,y_2 \}, \cdots , \{ x_t ,y_t \} \}$ which satisfies the following properties: (i) $\{ x_1 ,x_2 , \cdots ,x_t ,y_{1}, y_2 , \cdots ,y_t \} = G\backslash \{ 0 \}$, (ii) $\{ \pm (y_1 - x_i ) | \{ x_i ,y_i \} \in S \} = G\backslash \{ 0 \}$, (iii) $x_i + y_i \ne x_j + y_{i}$ if $i \ne j$, and $x_i + y_i \ne 0$, for any i.We present a fast algorithm for finding strong starters in Abelian groups.

In this paper we describe and discuss hill-climbing algorithms for the construction of one- factorizations of complete graphs, and orthogonal one-factorizations of complete graphs (i.e., Room squares).

Adult rabbit lung surfactant was radioactively labelled with [3H]palmitate and isolated by centrifugation. This material was instilled into the trachea of fetal rabbits prematurely delivered on the 27th gestational day. A similar preparation of unlabelled surfactant was used to measure the effects on pressure-volume characteristics in lungs of 27th day fetuses. Tissue sections were prepared from the lungs of all animals and morphometric and autoradiographic determinations made. Surfactant instillation improved pressure-volume relationships in fetal rabbit lungs. Histologically, although only the middle right lobe seemed to show significant qualitative improvement in expansion after surfactant treatment, quantitative assessment indicated that the surfactant preparation had significantly increased the mean alveolar cross-sectional areas in all three lobes of right lungs. In addition, distribution of autoradiographic grains indicated that 8–25% were located over the alveolar spaces while approximately half this percentage was present over tissue at the level of the alveolus. These results indicate that intratracheal instillation of surfactant supplements the endogenous surfactant at the level of the alveolus.

Several properties of a pellet fraction obtained on centrifuging amniotic fluid at 10,000 x g for 20 min were investigated. From these analyses, we defined a developmental profile which appears to describe the maturational process of the fetal lung surfactant system. At 14 to 18 wk gestation, the pellet fraction consisted of membrane-bound vesicles without internal lamellae. The phospholipid composition did not resemble that of surfactant, the major phospholipid being sphingomyelin. This stage, designated as presurfactant, persisted until 30 to 32 wk gestation. After this time, the phospholipid concentration of the pellet fraction increased continuously throughout development, and gradual but continuous changes in phospholipid composition were observed. Lecithin and phosphatidylinositol increased between 39 and 35 wk gestation. Interruption of pregnancies at this stage, termed onset of surfactant synthesis, resulted in 100 incidence of respiratory distress syndrome. From 36 wk gestation to postterm, the pellet fraction contained structures with the characteristic morphology of the lamellar inclusion bodies. The presence of single membrane components in these preparations did not contribute to the phospholipid composition. Early formed lamellar bodies lacked phosphatidylglycerol and had a high content of phosphatidylinositol. Once phosphatidylglycerol appeared in the lamellar body fraction, it continued to increase, accompanied by a decrease in phosphatidylinositol with little change in lecithin. A phosphatidylglycerol value of greater than 1 of the total phospholipids appeared to represent the stage of maturity at which there was no risk of respiratory distress syndrome.

An exact (λ, t)‐covering, B, of a v‐set X, is a collection of proper subsets of X, with the property that each t‐subset of Xis contained in exactly λ members of B. Let g(λ, t, v) denote the minimum cardinality |B| of an exact (λ, t)‐covering of X. We show that if q⩾ 3 is a prime power then g(1, 3, q2+ 1) = q3+ q, the minimal configuration being an inversive plane. We also show that g(1, 3, q2− α) = q3+ qfor q⩾ 4 and α 0, where α is small relative to q. A few isolated values of g(1,t, v) for t> 3 are also obtained.

Forty-nine patients with suspected intrauterine growth retardation (IUGR) were studied under rigid experimental conditions to determine baseline fetal breathing movement (FBM) activity and the response to 90-minute maternal glucose infusion, as compared to that of normal control subjects. Patients with IUGR showed a normal amount of FBMs during maternal fasting. All groups exhibited a significant increase in FBMs after glucose was administered. During the final 60 minutes of the glucose infusion, the severe IUGR group (weight for gestational age less than the third percentile) showed less FBM activity (p<0.01) than the other study and control groups.

Abstract: AHowell design of side s andorder 2n, or more briefly, anH(s, 2n), is anss array in which each cell either is empty or contains an unordered pair of elements from some 2n-set, sayX, such that (a) each row and each column is Latin (that is, every element ofX is in precisely one cell of each row and each column) and (b) every unordered pair of elements fromX is in at most one cell of the array. Atrivial Howell design is anH(s, 0) havingX= and consisting of anss array of empty cells. A necessary condition onn ands for the existence of a nontrivialH(s, 2n) is that 0

Abstract: In this paper, we study 2-(v, k, 1) designs with automorphisms of prime orderp, having the maximum possible number of fixed points. We prove an upper bound on the number of fixed points, and we study the structure of designs in which this bound is met with equality (such a design is called ap-MFP(v, k)). Several characterizations and asymptotic existence results forp-MFP(v, k) are obtained. For (p, k)=(3,3), (5,5), (2,3) and (3,4), necessary and sufficient conditions onv are obtained for the existence of ap-MFP(v, k). Further, for 3≤k≤5 and for any primep≡1 modk(k−1), we establish necessary and sufficient conditions onv for the existence of ap-MFP(v, k).

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