Meconium passage in newborn infants is a developmentally programmed event normally occurring within the first 24 to 48 hours after birth. Intrauterine meconium passage in near-term or term fetuses has been associated with fetomaternal stress factors and/or infection, whereas meconium passage in postterm pregnancies has been attributed to gastrointestinal maturation. Despite these clinical impressions, little information is available on the mechanism(s) underlying the normal meconium passage that occurs immediately after birth or during the intrauterine period of fetal development. Birth itself is a stressful process and it is possible that fetal stress-mediated biochemical events may regulate the meconium passage occurring either during labor or after birth. Aspiration of meconium during intrauterine life may result in or contribute to meconium aspiration syndrome (MAS), representing a continued leading cause of perinatal death. This article reviews aspects of meconium passage in utero, its consequences, and management.

Rat pups were malnourished during the first 3 weeks after birth. Experimental rats were injected intraperitoneally with 1 mg N-acetylneuraminic acid (NANA) per 50 g body weight daily from 14 to 21 days postnatally. Control animals were similarly injected with 1 mg glucose per 50 g body weight. At 21 days of age, the rats were tested in an open field and their brains analyzed for protein, DNA, ganglioside NANA and glycoprotein NANA. The administration of NANA was associated with an increase in cerebral and cerebellar ganglioside and glycoprotein NANA concentrations. However, it had no effects on brain weight, cell size and number. There was also a reduction in the expected behavioral abnormalities secondary to malnutrition. At 21 days of age, similarly treated littermates of the experimental animals were weaned to a stock diet and tested in a Y maze at 6 months of age. Rats treated with NANA learned the maze quicker than controls and the previously noted changes in brain biochemistry were found to have persisted. Intraperitoneal injection of [14C]NANA into malnourished rats during the same period showed that it was readily incorporated into brain glycoproteins and gangliosides. The possibility that the brain concentration of NANA has an effect on behavior is discussed.

It has been known since the first photon correlation experiments were reported' ' that the counts registered by a photoelectric detector illuminated by a light beam from a thermal source do not arrive completely at random.In time intervals of order or less than the coherence time of the light, the probability of counting two pulses is greater than that expected for random events. The "bunching" of photocounts has been most clearly demonstrated in the excess coincidence experiments with two coherently illuminated photodetectors. ' 4 Somewhat less direct evidence for the bunching is also contained in measurements of the fluctuations of counts registered by a single photodetector in a finite time interval. ' Yet one of the most interesting features of the bunching, that the distribution of time intervals between successive counts is closely related to the spectral profile in the ca.se of thermal light, and may be used to determine the spectral profile, has not so far been examined or put to use. ' %e have measured the distribution of time intervals between successive photon counts of an illuminated photomultiplier in the range 1.4 to 10 nsec, for the light from a low-pressure Hg' ' discharge lamp. The measurements lead to a spectral width of the blue Hg' ' line of about 200 Mc/sec. Although this appears to be the first attempt to determine the spectral profile of light from a thermal source in this way, somewhat similar measurements have been reported for light from a "pseudothermal" source,~' which is produced by moving a piece of ground glass in the path of a laser beam.The experimental setup, which was similar to one that was briefly described by Mandel, ' is shown in Fig. 1 Fig. 1.The results of the measurement are shown in Fig. 2(a), which gives the two-pulse counting rate as a, function of the time interval 7,. It will be seen that there is an increase in the counting rate when~, becomes less than 2 or 3 nsec, which is of the order of the coherence time. This illustrates the bunching phenomenon. For comparison, the results of similar measurements carried out with a tungsten lamp as source are shown in Fig. 2 This slope is much less than is indicated by the broken curve in Fig. 2(a). Although the value of fo Iy(~) I'dr is not known, since a portion of the curve is missing in Fig. 2(a), yet it is possible to make an estimate of the value of the integral (say 2 to 8 nsec) merely by inspection of Fig. 2 Fig. 2(a J. Phys. 36, 871 (1958 a b s t r a c t I try to present a small view of the properties and issues related to astronomical interferometry observations. I recall a bit of history of the technique, give some basic assessments to the principle of interferometry, and finally, describe physical processes and limitations that affect optical long baseline interferometry and which are, in general, very useful for everyday work. Therefore, this text is not intended to perform strong demonstrations and show accurate results, but rather to transmit the general ''feeling" one needs to have to not be destabilise...

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A female fetus with brain malformations, multicystic kidneys, absence of the right thumb, and a posterior cleft of palate was delivered at 32 weeks of gestation. Cytogenetic studies including FISH showed a novel intrachromosomal triplication of the proximal long arm of chromosome 2 (q11.2-q21), resulting in tetrasomy for this segment. The middle repeat was inverted. At least 11 patients with intrachromosomal triplications have been reported, mostly involving chromosome 15q. The mechanism involved in formation of these rearrangements is compatible with U-type exchange events among three chromatids.