Isolation and characterization of new MIKC*-Type MADS-box genes from the moss Physcomitrella patens.

MADS-box genes encode for a large family of transcription-regulating proteins, which were isolated from all groups of eukaryotic organisms. The plant-specific MIKC-type MADS-box genes have been intensively analyzed for their roles in controlling developmental processes. Well-known are the MADS-box genes acting as homeotic selector genes in the differentiation of whorls of floral organs in seed plants. The MADS-box gene family has also been studied in non-flowering plants, such as lycophytes, pteridophytes, and bryophytes. The analysis of MADS-box genes in the moss Physcomitrella patens led to the identification of a new class of MIKC-type genes, designated as MIKC*-type genes. The MIKC*-type genes possess a number of structural features which clearly distinguish them from the already known MIKC-type genes. Recently, orthologues of the Physcomitrella MIKC*-type genes were found in Arabidopsis thaliana, demonstrating the conservation of these genes in tracheophytes. Here, we report the isolation of two new MIKC*-type MADS-box genes from Physcomitrella. Structural features and expression patterns of these genes were analyzed. The contribution of our findings to a better understanding of the evolution of MIKC*-type genes in land plants is discussed.

Temperament in full-term and preterm infants: stability over ages 6 to 24 months.

Temperament stability over successive ages in the first 2 years of life was evaluated for 109 full-term and 81 preterm infants who were assessed at 6, 9, 12, 18, and 24 months. At each age, the infant was engaged in a series of age-appropriate vignettes in the laboratory, using a structured sequence of activities. Ratings were made of emotional tone, attentiveness, activity, and orientation to staff. Correlations indicated that, for full-term infants, there was significant stability across ages (6 to 9 months, 9 to 12 months, 12 to 18 months, and 18 to 24 months) for all variables. For preterm infants, stability across ages generally was not observed until later infancy, or was sporadic. The findings indicated that, for full-term infants, stable aspects of temperament were apparent during the first year of life. In contrast, individual differences were not as clearly defined for preterm infants until later ages.

Discordant and nondiscordant twins: comparative multimethod risk assessment in the neonatal period.

Full-term neonate twins from weight-discordant pairs were compared with nondiscordant pairs on perinatal variables, minor physical anomalies, developmental status, and temperament/interactive measures. For perinatal variables, twins from the top quartile of discordance were found to be at higher risk than other twins. Both the total group of discordant twins and twins with the most extreme discordance had higher weighted minor physical anomaly scores, more minor physical anomalies, and lower developmental status scores than nondiscordant twins. For temperament, twins in the extreme discordant group were more active while awake than twins in the nondiscordant group. The results are discussed in relation to expected group differences in perinatal measures, the timing during gestation of insults related to discordance and minor physical anomalies, and the significance of behavioral differences between cotwins versus between groups. Implications for developmental risk for both twins from discordant pairs are discussed.

Neonatal temperament in full-term twin pairs discordant for birth weight.

To examine the significance of relative birth weight of cotwins for neonatal temperament, 70 pairs of full-term twins who were at least 15% discordant for birth weight were assessed. The assessment focused on irritability, resistance to soothing, activity, reactivity, and reinforcement value. The larger twin of the pair was more irritable, more difficult to soothe, more active while awake, more active during sleep, less reactive to visual and auditory stimuli, and less reinforcing to the examiner than the smaller cotwin. Both the lighter and heavier cotwins exhibited behavioral discrepancies. The results are discussed in relation to prenatal influences on early behavioral development, and implications for differential parent-infant interaction with each twin.

Prenatal cocaine exposure and prematurity: neurodevelopmental growth.

The consequences of prematurity and prenatal cocaine exposure on early neurobehavior and physical growth were examined longitudinally in a sample of 20 cocaine-exposed and 20 non-exposed preterm neonates. The magnitude of the difference in physical growth acceleration related to prenatal cocaine exposure increased with increasing birth gestational age, whereas growth rate differences in irritability decreased. In contrast, prenatal cocaine exposure, independent of prematurity, was related to reduced attention skills at 36 weeks conceptional age and increased rates of neurobehavioral change. The effects of prenatal cocaine exposure differed with respect to the degree of prematurity, depending on the nature of the outcome examined, suggesting differing windows of vulnerability for different outcome domains. The usefulness of a developmental growth perspective was demonstrated.

Visual and auditory orienting responses in preterm infants: a comparison of three cohorts over time.

Visual and auditory orienting responses were compared in three cohorts of preterm infants (N = 351) born between 1977 and 1987. The infants were divided into one group born between 25 and 34 weeks gestational age (n = 140) and one group born between 35 and 37 weeks gestational age (n = 211). Ratings were made of the infants' best orienting responses to a bull's-eye, rattle, bell, voice, and face plus voice combined. Analyses of covariance were computed to adjust for changes in perinatal variables between 1977 and 1987. For both groups, there were significant differences between cohorts on orienting to the bull's-eye, with a trend for the 25- to 34-week group on orienting to the rattle. Behavioral outcome for preterm infants has improved with changes in neonatal intensive care.

Mothers' ratings of infant temperament: relation to neonatal latency to soothe by pacifier.

Latency to soothe by a pacifier in the neonatal period was assessed for 107 full-term infants. When the infants were 9 and 12 months old, their mothers rated their temperament on standardized questionnaires. Correlations were computed between the neonatal latencies to soothe and the temperament ratings. When compared with neonates who soothed more quickly, neonates who took longer to soothe were likely to be rated at 9 months as more active, more rhythmic, more approachful to new situations, and more adaptable; and at 12 months as more approachful, more pleasant in mood, and more The results are discussed in terms of developmental stages and individual variability in maturation, a shared underlying dimension of behavior for motor activity and emotionality, and a link across time between objective ratings of behavior and maternal views of infant temperament.

Implications of sex differences in neonatal temperament for early risk and developmental/environmental interactions.

Sex differences in neonatal temperament were examined in 30 pairs of full-term, opposite-sex twins. Behavior was assessed during feeding, during sleep, while awake for orienting responses, in response to a stressor, and for measures of spontaneous irritability and soothability. Composite and summary scales described irritability, resistance to soothing, reactivity, reinforcement value of the infant's behavior, activity during sleep, and activity while awake. Analyses of variance of paired comparisons performed separately for each behavioral area indicated that female neonates were more irritable and more difficult to soothe than male neonates. The results are discussed in terms of maturational effects on neonatal behavior, implications for infant-caregiver interaction, and their relation to environmental influences on development.

Extending water vapor trend observations over Boulder into the tropopause region: Trend uncertainties and resulting radiative forcing.

Thirty years of balloon-borne measurements over Boulder (40°N, 105°W) are used to investigate the water vapor trend in the tropopause region. This analysis extends previously published trends, usually focusing on altitudes greater than 16 km, to lower altitudes. Two new concepts are applied: (1) Trends are presented in a thermal tropopause (TP) relative coordinate system from -2 km below to 10 km above the TP, and (2) sonde profiles are selected according to TP height. Tropical (TP z > 14 km), extratropical (TP z < 12 km), and transitional air mass types (12 km < TP z < 14 km) reveal three different water vapor reservoirs. The analysis based on these concepts reduces the dynamically induced water vapor variability at the TP and principally favors refined water vapor trend studies in the upper troposphere and lower stratosphere. Nonetheless, this study shows how uncertain trends are at altitudes -2 to +4 km around the TP. This uncertainty in turn has an influence on the uncertainty and interpretation of water vapor radiative effects at the TP, which are locally estimated for the 30 year period to be of uncertain sign. The much discussed decrease in water vapor at the beginning of 2001 is not detectable between -2 and 2 km around the TP. On lower stratospheric isentropes, the water vapor change at the beginning of 2001 is more intense for extratropical than for tropical air mass types. This suggests a possible link with changing dynamics above the jet stream such as changes in the shallow branch of the Brewer-Dobson circulation.

Mass-analyzed threshold ionization spectroscopy of pyrimidine: determining the geometry in the first excited and the ionic ground states.

Vibrational spectra of the pyrimidine cation in the electronic ground state were measured via several intermediate states of the first excited state (0(0),16a(1), 16a(2), 16a(4), 16b(1), 10b(1), 6b(2), 6a(1), 1(1), 4(1), 4(2) and 12(1)) by mass-analyzed threshold ionization spectroscopy. For the first time, several vibrational modes could be assigned in the first excited and the ionic ground states. Anharmonic coupling is shown to occur in the first excited state due to Fermi resonance between the 1(1) and the 16a(4) vibrations. From the results of the measurements and calculations presented here, pyrimidine is predicted to be planar in the first excited and the ionic ground states, and it belongs to the C(2V) point group.

Mass-analyzed threshold ionization spectroscopy of pyridine. Structural distortion in the first excited state.

For the first time, vibrational spectra of the pyridine cation in the electronic ground state have been measured via several intermediate states (0(0), 16b0(2), 16b0(4), 6a0(1), 6b(1), 16a0(1), 10a0(1) and 12(1)) by Mass-Analyzed Threshold Ionization (MATI) spectroscopy. From the MATI spectra, the adiabatic ionization energy of pyridine has been determined to be 74,185 +/- 6 cm(-1) (9.1978 +/- 0.0008 eV). Several vibronic modes in the ionic ground state could be assigned for the first time. An intensity gain of vibrations having b1 symmetry could be observed by activating the ion ground state. Also, a breakdown of the "delta nu = 0 propensity rule" for the excitation via the 16b(2) and 16b(4) states of the first excited states are displayed in the recorded spectra. In conjunction with ab initio calculations these observations can be explained by a strong geometrical distortion along the 16b vibration in the first excited state, leading to a "boat distortion".

Maternal alcohol and pentazocine abuse: neonatal behavior and morphology in an opposite-sex twin pair.

A pair of preterm, opposite-sex twins were examined during the lying-in period for behavioral and morphological effects of maternal alcohol and pentazocine abuse during pregnancy. A few morphological features typical of fetal alcohol syndrome were observed in each infant, and the male infant only was above the standardized mean in minor physical anomalies. The male's behavioral scores were more likely to be deviant from the standardized mean than the female's. Specifically, the male was more irritable, both spontaneously and in response to specific stimuli; highly active while awake and handled for the presentation of stimuli; more active than average during sleep; and low on ratings that reflect the attitude of the examiner toward the infant. These findings imply individual and gender differences in behavioral susceptibility to teratogens.

Temperament and neonatal risk in full-term and preterm combined vaginal/cesarean section twin pairs.

Ten pairs of full-term and 8 pairs of preterm twins from combined vaginal and Cesarean section deliveries were evaluated on measures of neonatal temperament, developmental status, and integrity to determine if the Cesarean-delivered infant was compromised relative to its vaginally-delivered twin. There were no significant differences, within groups, between the vaginal and Cesarean section infants on measures of risk and developmental status. Analyses of variance of paired comparisons performed on the temperament measures indicated that, for the full-term group, there were no significant differences in ratings between vaginally and Cesarean-delivered infants. In contrast, preterm infants delivered by Cesarean section were more active during sleep than their vaginally-delivered cotwins. This finding, together with previous findings demonstrating a relation between this measure and temperament at 9, 18, and 24 months of age, suggested that the preterm Cesarean-delivered infant may be at risk in this area when compared with its twin. In the main, however, the results demonstrated that infants born by Cesarean section following vaginal delivery of their twins were not more compromised than their twin siblings.

Within-pair differences in newborn twins: effects of gender and gestational age on behavior.

The behavior of 120 full term and 160 preterm newborn twins was assessed in several key areas: Irritability, soothability, reactivity, reinforcement value, and activity level. Infants were assessed during various situations so that aggregate, or summary, scores representing each behavioral area could be obtained. Evaluations were made during a feeding period, an active sleep period, an awake alert period during which orienting and interactional behaviors were observed, a quiet period during which reactivity to stress was observed, and any fussy periods during which irritability and soothability were assessed. Significant within-twin-pair concordance of behavior was obtained for each of the areas of behavior, suggesting the influence of constitutional variables on neonatal behavior. Analysis of these data by sex resulted in significant within-pair concordance of behavior for same-sex but not for opposite-sex twins. The actual ratings on these behaviors differentiated between full term and preterm infants. Increased behavioral deviance was observed with increasing prematurity in the areas of soothability and activity level. The results are discussed in terms of increased risk factors for preterm twins.

Genetic influences on neonatal temperament.

The genetic contribution to temperament was assessed during the neonatal period in 172 newborn infants from 47 pairs of monozygotic (MZ) and 39 pairs of same-sex dizygotic (DZ) twins. Zygosity was not related to the neonatal temperament variables. Examination of the scores for twin concordance indicated significant within-pair concordance in temperament ratings, but MZ twins were not more like each other than DZ twins. The results suggested that neonatal temperament was influenced by environmental factors. Further analyses indicated that neonatal temperament was influenced by perinatal variables such as birth weight, 1- and 5-minute Apgar scores, and number of days spent in the hospital. It was concluded that there was no clear pattern of genetic influence on neonatal temperament, and that nonshared environmental factors were an important source of variance for temperament during this period.

Neonatal temperament in monozygotic and dizygotic twin pairs.

To determine if neonatal temperament was influenced by genetic factors, temperament was assessed in 316 newborn twins from 47 pairs of monozygotic (MZ) twins, 39 pairs of same-sex dizygotic (DZ) twins, and 72 pairs of opposite-sex dizygotic twins. The neonatal assessment focused on irritability, resistance to soothing, activity level, reactivity, and reinforcement value. Examination of intraclass correlations for MZ and DZ twins and the results of model-fitting analyses indicated that heritability estimates for neonatal temperament were not significantly different from zero, and that there was substantial environmental influence on neonatal temperament. Specific perinatal indicators of risk were found to account for some of the intrapair differences observed for the behavioral variables. It was concluded that there is no clear pattern of genetic influence on temperament in the neonatal period.

Temperament development to 30 months of age in discordant twin pairs.

Twins within pairs often have different weights at birth. A difference of 15% or greater is defined as discordance for weight and is considered to place one or both infants at risk. Temperature differences had been found in the neonatal period for fullterm discordant cotwins, but not for preterm discordant cotwins, suggesting that continued gestation for discordant twins was a risk variable for early behavior. 30 pairs of fullterm and 17 pairs of preterm discordant pairs were followed at 6, 9, 12, 18, 24, and 30 months of age. Group differences were observed for the longitudinal maintenance of cotwin discordance in physical measures, with preterm cotwins becoming more like each other. In laboratory assessments, temperament differences no longer were observed between the larger and smaller cotwins. Questionnaires indicated that mothers generally did not differentiate between their larger and smaller cotwin children in temperament ratings, except for ratings of mood for the fullterm pairs. Thus, emotionality was the only temperament dimension that differentiated between the fullterm discordant twins both in the neonatal period and at later ages. In the main, it was concluded that the fullterm discordant twins overcame the adverse in-utero influences on early behavioral development.

Discordant twin pairs: the relation between gestational age and neonatal temperament differences in cotwins.

Temperament differences between cotwins at least 15% discordant for birth-weight were compared for a group of 66 preterm twin pairs and a group of 70 fullterm twin pairs, assessed in the neonatal period. The assessment focused on irritability, resistance to soothing, activity, reactivity, and reinforcement value. For the most part, significant differences were not obtained between discordant preterm cotwins. Previous research [10] had demonstrated that the larger fullterm twin of discordant pairs was more irritable, more difficult to soothe, more active while awake and during sleep, less reactive to visual and auditory stimuli, and less reinforcing to the examiner than the smaller cotwin. It was concluded that, for the behavioral variables measured, the fullterm group is at higher risk than the preterm group, and that both the lighter and the heavier discordant twins displayed signs of early behavioral risk. The findings suggested that the continued gestation for cotwins discordant in weight may be a risk period for early temperament development of the twins.

Predicting infant temperament from neonatal reactivity for AGA/SGA twin pairs.

The predictive relation between neonatal reactivity and 12-, 18-, and 24-month temperament was assessed for 22 appropriate-for-gestational-age (AGA)/small-for-gestational-age (SGA) twin pairs. Neonatal reactivity included ratings of visual and auditory orienting responses to a bull's-eye, rattle, bell, voice, and face plus voice combined, as well as alertness. Infant temperament ratings were made of emotional tone, activity, attentiveness, and social orientation to staff during age-appropriate activities in the laboratory. There were no group differences in the neonatal or infant ratings. For AGA twins, a pattern of predictive correlations was obtained between neonatal reactivity and temperament at each age. A similar predictive pattern was not observed for the SGA twins. Group differences in rates of maturation related to stresses associated with intrauterine growth retardation influenced the significance of the neonatal variables for later temperament development.

Effects of chorion type on neonatal temperament differences in monozygotic twin pairs.

Monozygotic (MZ) twins with a known chorion type were assessed in the neonatal period to determine if placentation was related to twin similarity in early temperament development. The sample included 48 pairs with monochorionic placentas and 29 pairs with dichorionic placentas. The assessment focused on irritability, resistance to soothing, activity while awake, activity during sleep, reactivity, and reinforcement value. There were no differences between the monochorionic and the dichorionic twins in any of the temperament ratings. Chorion type was not related to cotwin similarity on any of the temperament ratings. It was concluded that differences in prenatal environment reflected in placentation type did not affect early temperament for MZ twins.