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BACKGROUND: Previous research suggests, though not consistently, that maternal psychological distress during pregnancy leads to adverse birth outcomes. We investigated whether maternal psychological distress affects fetal growth during the period of mid-pregnancy until birth. METHOD: Pregnant women (n=6313) reported levels of psychological distress using the Brief Symptom Inventory (anxious and depressive symptoms) and the Family Assessment Device (family stress) at 20.6 weeks pregnancy and had fetal ultrasound measurements in mid- and late pregnancy. Estimated fetal weight was calculated using head circumference, abdominal circumference and femur length. RESULTS: In mid-pregnancy, maternal distress was not linked to fetal size. In late pregnancy, however, anxious symptoms were related to fetal size after controlling for potential confounders. Anxious symptoms were also associated with a 37.73 g [95% confidence interval (CI) -69.22 to -6.25, p=0.019] lower birth weight. When we related maternal distress to fetal growth curves using multilevel models, more consistent results emerged. Maternal symptoms of anxiety or depression were associated with impaired fetal weight gain and impaired fetal head and abdominal growth. For example, depressive symptoms reduced fetal weight gain by 2.86 g (95% CI -4.48 to -1.23, p<0.001) per week. CONCLUSIONS: The study suggests that, starting in mid-pregnancy, fetal growth can be affected by different aspects of maternal distress. In particular, children of prenatally anxious mothers seem to display impaired fetal growth patterns during pregnancy. Future work should address the biological mechanisms underlying the association of maternal distress with fetal development and focus on the effects of reducing psychological distress in pregnancy. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate whether maternal anxiety that is temporary or chronic during the pre- and postnatal period predicts infant temperament. Mothers of 2997 infants in a population-based birth cohort reported levels of pregnancy-specific anxiety (Pregnancy Outcome Questionnaire) and general anxiety symptoms (Brief Symptom Inventory) prenatal and at 6 months postnatal. Temperament characteristics were assessed by maternal report using the Infant Behavior Questionnaire-Revised when the infants were 6 months of age. Maternal pregnancy-specific and general anxiety during the pre- and postnatal period were all independently associated with perceived infant temperamental difficulties. Chronically high maternal anxiety predicted the highest perceived infant activity level and negative affectivity. These findings show that different forms of maternal anxiety during both the pre- and postnatal period are independently related to perceived temperamental problems in infancy. They also emphasize the significance of chronic maternal anxiety for infant mental health. Copyright © 2009 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Cetyltrimethylammonium bromide (CTAB)-based methods are widely used to isolate DNA from plant tissues, but the unique chemical composition of secondary metabolites among plant species has necessitated optimization. Research articles often cite a "modified" CTAB protocol without explicitly stating how the protocol had been altered, creating non-reproducible studies. Furthermore, the various modifications that have been applied to the CTAB protocol have not been rigorously reviewed and doing so could reveal optimization strategies across study systems. We surveyed the literature for modified CTAB protocols used for the isolation of plant DNA. We found that every stage of the CTAB protocol has been modified, and we summarized those modifications to provide recommendations for extraction optimization. Future genomic studies will rely on optimized CTAB protocols. Our review of the modifications that have been used, as well as the protocols we provide here, could better standardize DNA extractions, allowing for repeatable and transparent studies., (© 2023 The Authors. Applications in Plant Sciences published by Wiley Periodicals LLC on behalf of Botanical Society of America.)

Premise: The use of cetyltrimethylammonium bromide (CTAB) is an effective and inexpensive method of extracting DNA from plants. The CTAB protocol is frequently modified to optimize DNA extractions, but experimental approaches rarely perturb a single variable at a time to systematically infer their effect on DNA quantity and quality., Methods and Results: We investigated how chemical additives, incubation temperature, and lysis duration affected DNA quantity and quality. Altering those parameters influenced DNA concentrations and fragment lengths, but only extractant purity was significantly affected. CTAB and CTAB plus polyvinylpyrrolidone buffers produced the highest DNA quality and quantity. Extractions from silica gel-preserved tissues had significantly higher DNA yield, longer DNA fragments, and purer extractants compared to herbarium-preserved tissues., Conclusions: We recommend DNA extractions of silica gel-preserved tissues that include a shorter and cooler lysis step, which results in purer extractions compared to a longer and hotter lysis step, while preventing fragmentation and reducing time., (© 2023 The Authors. Applications in Plant Sciences published by Wiley Periodicals LLC on behalf of Botanical Society of America.)

Premise: Staminodes are commonly studied in hermaphroditic flowers, in which a fraction of the androecium evolves into infertile structures, but few studies have addressed the evolution of staminodes as they occur through the loss of stamen function in carpellate flowers. Plants of Paronychia (Caryophyllaceae) are monoecious with hermaphroditic flowers with one staminodial whorl, except for the dioecious P. chartacea and P. minima. Dioecious species have carpellate flowers that evolved an additional whorl of staminodes, providing an exceptional opportunity to study a second origin of staminodes in the same flower., Methods: Using scanning electron microscopy, we observed the development of carpellate and staminate flowers to determine whether the developmental pathway of the staminodes in hermaphroditic flowers was co-opted during the evolutionary transition to unisexual flowers., Results: In carpellate flowers, antesepalous staminodes initiate as sterile anthers that develop similar to functioning stamens, but arrest before full development, leaving a rudimentary anther with lateral lobes that correspond to thecae. After antesepalous staminodes arrest, alternisepalous staminodes initiate as structures that correspond with filaments, as they do in staminate and hermaphroditic flowers., Conclusions: The second origin of staminodes in carpellate flowers evolved using a different developmental pathway than what had previously evolved in the alternisepalous whorl. The two androecial whorls in the same flowers are serialogous as members of the androecium, but are paralogous as staminodes on the basis of structural and developmental differences., (© 2023 Botanical Society of America.)

Background: How do xerophytic species thrive in environments that experience extreme annual drought? Although critical to the survival of many species, the genetic responses to drought stress in many non-model organisms has yet to be explored. We investigated this question in Mentzelia section Bartonia (Loasaceae), which occurs throughout western North America, including arid lands. To better understand the genetic responses to drought stress among species that occur in different habitats, the gene expression levels of three species from Mentzelia were compared across a precipitation gradient. Two de novo reference transcriptomes were generated and annotated. Leaf and root tissues were collected from control and drought shocked plants and compared to one another for differential expression. A target-gene approach was also implemented to better understand how drought-related genes from model and crop species function in non-model systems., Results: When comparing the drought-shock treatment plants to their respective control plants, we identified 165 differentially expressed clusters across all three species. Differentially expressed genes including those associated with water movement, photosynthesis, and delayed senescence. The transcriptome profiling approach was coupled with a target genes approach that measured expression of 90 genes associated with drought tolerance in model organisms. Comparing differentially expressed genes with a ≥ 2 log-fold value between species and tissue types showed significant differences in drought response. In pairwise comparisons, species that occurred in drier environments differentially expressed greater genes in leaves when drought shocked than those from wetter environments, but expression in the roots mostly produced opposite results., Conclusions: Arid-adapted species mount greater genetic responses compared to the mesophytic species, which has likely evolved in response to consistent annual drought exposure across generations. Drought responses also depended on organ type. Xerophytes, for example, mounted a larger response in leaves to downregulate photosynthesis and senescence, while mobilizing carbon and regulating water in the roots. The complexity of drought responses in Mentzelia suggest that whole organism responses need to be considered when studying drought and, in particular, the physiological mechanisms in which plants regulate water, carbon, cell death, metabolism, and secondary metabolites., (© 2021. The Author(s).)

The present study examined different conditions under which exclusion responding in conditional discrimination tasks would generate emergent equivalence relations in young children based on shared relationships with verbal labels. Both visual stimuli (Sets A, B, C, and D) and auditory stimuli (spoken words, Set N: N1 "correct"; N2: "incorrect") were used. Following a pilot study, three experiments were conducted, each involving eight preschool children. These experiments systematically investigated under which conditions responding by exclusion (i.e., responding away from a designated S - comparison in a matching to sample context) would generate sufficiently stable sample-S + relations for arbitrary stimulus classes to establish. The results showed that young children's exclusion responding under test conditions will only contribute to arbitrary stimulus class formation and expansion when training has already established two arbitrary stimulus classes involving at least two stimuli each. For young children to demonstrate emergent conditional discrimination performances that are indicative of the formation of equivalence relations, it is necessary to have training and/or reinforced exposure to both S + and S - control elements required for deriving the appropriate emergent relations with at least two conditional relations involving different samples. These findings not only contribute to existing research and theory on the conditions under which exclusion responding may contribute to fundamental language and learning processes, they also contribute to the experimental predictability of emergent conditional matching behaviours in preschool children by further unravelling the conditions under which emergent matching based on exclusion generates arbitrary conditional relations of equivalence., (Copyright © 2021 The Authors. Published by Elsevier B.V. All rights reserved.)

Ixodes acer n. sp., Ixodes giluwensis n. sp., Ixodes mirzai n. sp., Ixodes planiscutatus n. sp. and Ixodes stellae n. sp. (Acari: Ixodidae), are described based on females ex various marsupials (Dasyuromorphia: Dasyuridae, Diprotodontia: Petauridae, Peramelemorphia: Peramelidae), rodents (Rodentia: Muridae) and a bird (Galliformes: Megapodiidae) from Indonesia (Papua Province) and Papua New Guinea. Females of all new species are similar to those of I. luxuriosus Schulze, 1935, I. steini Schulze, 1935 and I. zaglossi Kohls, 1960, but can be distinguished from them and each other by the distinctness of lateral carinae and cervical grooves on the scutum, length of setae on the idiosoma, sculpture of the basis capituli and palpal segment I dorsally, size of the dorsal cornua, shape and sculpture of the palpal segment I ventrally, size of ventral spur on the palpal segment I, dental formula on the hypostome and measurements of various structures and their proportions. For comparative purposes the female of I. luxuriosus, I. steini and I. zaglossi is redescribed and lectotypes for I. luxuriosus and I. steini have been designated. Studied females of I. luxuriosus, I. steini and I. zaglossi were found on marsupials (Dasyuromorphia: Dasyuridae; Diprotodontia: Macropodidae, Petauridae, Phalangeridae, Pseudocheiridae; Peramelemorphia: Peramelidae), rodents (Rodentia: Muridae) and echidnas (Monotremata: Tachyglossidae) in Indonesia (Papua Province) and Papua New Guinea.

Although the importance of biogeography in the speciation process is well recognized, the fundamental role of geographic diversification during adaptive radiations has not been studied to determine its importance during the adaptive radiation process. We examined the relationship between lineage and regional diversification patterns in the South American rodent subfamily Sigmodontinae, one of the best candidates for an adaptive radiation in mammals, to propose a conceptual framework for geographic transitions during adaptive radiations. We reconstructed a time-calibrated phylogeny from four nuclear genes and one mitochondrial gene for 77% of sigmodontine diversity. Historical biogeography was reconstructed among 14 regions, for which we applied a sliding-window approach to estimate regional transition rates through time. We compared these rate patterns and measured whether regions consisted of species that were more phylogenetically related than expected by chance. Following the initial South American colonization around 7 million years ago, multiple expansions from northern regions correlated with a burst of speciation. Subsequently, both diversification and regional transition rates decreased overall and within the majority of regions. Despite high regional transition rates, nearly all regional assemblages were phylogenetically clustered, indicating that within-region diversification was common. We conclude that biogeographic complexity and partitioning played a profound role in the adaptive radiation of the South American Sigmodontinae (Oryzomyalia), the degree to which is determined by the relative scales of spatial variation and dispersal abilities.

Premise of the Study: A repeated pattern of American amphitropical disjunct species or sister species distributed on either side of the equator has long-fascinated botanists, but the modes of these disjunctions remain untested. We evaluated diaspore morphology to generate hypotheses on probable dispersal mechanisms., Methods: The sizes and structures of diaspores, habit, habitat, distribution, and dispersal units were collected for 108 species from literature searches and herbarium specimens. Variation was evaluated with summary statistics, χ 2 tests with Monte Carlo simulations, ANOVAs, and the nonparametric Mann-Whitney test., Key Results: Seeds were the dispersing diaspore in 38.0% of the species, 45.4 were dispersed as fruits, and the remaining were dispersed as infructescences or spores. Diaspores were epizoochorous (52.8%), anemochorous (20.4%), achorous (15.7%), endozoochorous (8.3%), and hydrochorous (2.8%). Epizoochory was significantly greater than expected. Zoochory occurred more frequently than expected when considering achorous diaspores as animal-dispersed. Most species were associated with wetland, woodland, and grassland habitats. An ANOVA revealed that diaspores associated with hydrochory were larger and anemochory was smaller; all other syndromes were not significantly different., Conclusions: Botanists have long-held the assumption that bird migrations are responsible for amphitropical disjunctions. Our results support this hypothesis, with the majority of these events occurring by external attachment of small fruits. However, our results also indicate that anemochory might play a greater role in producing amphitropical distributions than previously thought and at a greater rate than endozoochory or hydrochory., (© 2017 Botanical Society of America.)

We combined new sequence data for more than 300 muroid rodent species with our previously published sequences for up to five nuclear and one mitochondrial genes to generate the most widely and densely sampled hypothesis of evolutionary relationships across Muroidea. An exhaustive screening procedure for publically available sequences was implemented to avoid the propagation of taxonomic errors that are common to supermatrix studies. The combined data set of carefully screened sequences derived from all available sequences on GenBank with our new data resulted in a robust maximum likelihood phylogeny for 900 of the approximately 1,620 muroids. Several regions that were equivocally resolved in previous studies are now more decisively resolved, and we estimated a chronogram using 28 fossil calibrations for the most integrated age and topological estimates to date. The results were used to update muroid classification and highlight questions needing additional data. We also compared the results of multigene supermatrix studies like this one with the principal published supertrees and concluded that the latter are unreliable for any comparative study in muroids. In addition, we explored diversification patterns as an explanation for why muroid rodents represent one of the most species-rich groups of mammals by detecting evidence for increasing net diversification rates through time across the muroid tree. We suggest the observation of increasing rates may be due to a combination of parallel increases in rate across clades and high average extinction rates. Five increased diversification-rate-shifts were inferred, suggesting that multiple, but perhaps not independent, events have led to the remarkable species diversity in the superfamily. Our results provide a phylogenetic framework for comparative studies that is not highly dependent upon the signal from any one gene.

Secondary calibrations (calibrations based on the results of previous molecular dating studies) are commonly applied in divergence time analyses in groups that lack fossil data; however, the consequences of applying secondary calibrations in a relaxed-clock approach are not fully understood. I tested whether applying the posterior estimate from a primary study as a prior distribution in a secondary study results in consistent age and uncertainty estimates. I compared age estimates from simulations with 100 randomly replicated secondary trees. On average, the 95% credible intervals of node ages for secondary estimates were significantly younger and narrower than primary estimates. The primary and secondary age estimates were significantly different in 97% of the replicates after Bonferroni corrections. Greater error in magnitude was associated with deeper than shallower nodes, but the opposite was found when standardized by median node age, and a significant positive relationship was determined between the number of tips/age of secondary trees and the total amount of error. When two secondary calibrated nodes were analyzed, estimates remained significantly different, and although the minimum and median estimates were associated with less error, maximum age estimates and credible interval widths had greater error. The shape of the prior also influenced error, in which applying a normal, rather than uniform, prior distribution resulted in greater error. Secondary calibrations, in summary, lead to a false impression of precision and the distribution of age estimates shift away from those that would be inferred by the primary analysis. These results suggest that secondary calibrations should not be applied as the only source of calibration in divergence time analyses that test time-dependent hypotheses until the additional error associated with secondary calibrations is more properly modeled to take into account increased uncertainty in age estimates.

Background: The effects of child care services on several domains of child development have been extensively investigated, but evidence regarding the effects of child care on language development remains inconclusive., Methods: Within a large-scale population-based study, we examined the longitudinal associations between non-parental child care and language development from 1 to 6 years (n = 5375)., Results: Results showed that more hours in non-parental child care were associated with better language abilities. However, more hours in care in the first year of life were associated with less language proficiency at ages 1 to 1.5. At later ages, this effect disappeared and language proficiency increased. Furthermore, children who spent more hours in centre-based care had better language scores than children in home-based care. Ethnicity, socio-economic status, gender or parity did not change these results., Conclusions: This large, multi-ethnic study demonstrates beneficial effects of non-parental child care, particularly centre-based care, on language proficiency later in childhood., (© 2015 John Wiley & Sons Ltd.)

Little is known about the relationship between diurnal cortisol secretion patterns and cognitive function early in life. This population-based study examined whether diurnal cortisol rhythms and cognitive functioning in toddlers are related. Within the Generation R Study, parents of 364 infants (median age: 14.2 months) collected saliva samples at five moments during one day. We assessed the diurnal cortisol rhythm by calculating the area under the curve (AUC), the cortisol awakening response (CAR), and the diurnal slope. Verbal cognitive functioning and fine motor development was determined at age 18 months. Nonverbal cognitive functioning was assessed at age 30 months. A more positive CAR was associated with a lower risk of delay in language comprehension (OR per 1-SD CAR: 0.62, 95%CI: 0.40-0.98, p = .04), a lower risk of nonoptimal fine motor development (OR per 1-SD slope: 0.74, 95%CI: 0.57-0.96, p = .03), and a lower risk of delay in nonverbal cognitive development (OR per 1-SD CAR: 0.58, 95%CI: 0.38-0.90, p = .02). Also, children with flatter slopes had a lower risk of delay in nonverbal cognitive development (OR per 1-SD slope: 0.51, 95%CI: 0.34-0.76, p = .001). Higher AUC levels were associated with a higher risk of delay in language production. These results show that variations in diurnal cortisol rhythms are already associated with variations in cognitive functioning at a young age. Infants with a diurnal cortisol pattern indicative of less stress and more cortisol reactivity, that is, lower AUC levels and a more positive CAR, show a lower risk of delay in cognitive functioning as toddlers.

Why some clades are more species-rich than others is a central question in macroevolution. Most hypotheses explaining exceptionally diverse clades involve the emergence of an ecological opportunity caused by a major biogeographic transition or evolution of a key innovation. The radiation of muroid rodents is an ideal model for testing theories of diversification rates in relation to biogeography and ecological opportunity because the group is exceptionally species-rich (comprising nearly one-third of all mammal species), it is ecologically diverse, and it has colonized every major landmass except New Zealand and Antarctica, thus providing multiple replicate radiations. We present an extension of the conventional ecological opportunity model to include a geographic incumbency effect, develop the largest muroid phylogeny to date, and use this phylogeny to test the new model. The nearly 300-species phylogeny based on four nuclear genes is robustly resolved throughout. Consistent with the fossil record, we identified Eurasia as the most likely origin of the group and reconstructed five to seven colonizations of Africa, five of North America, four of Southeast Asia, two of South America, two of Sahul, one of Madagascar, and eight to ten recolonizations of Eurasia. We accounted for incomplete taxon sampling by using multiple statistical methods and identified three corroborated regions of the tree with significant shifts in diversification rates. In several cases, higher rates were associated with the first colonization of a continental area, but most colonizations were not followed by bursts of speciation. We found strong evidence for diversification consistent with the ecological opportunity model (initial burst followed by density-dependent slowdown) in the first colonization of South America and partial support for this model in the first colonization of Sahul. Primary colonizers appear to inhibit the ultimate diversity of secondary colonizers, a pattern of incumbency that is consistent with ecological opportunity, but they did not inhibit initial diversification rates of secondary colonizers. These results indicate that ecological opportunity may be a general but weak process in muroids and one that requires specific circumstances to lead to an adaptive radiation. The total land area, length of time between colonizations, and rank of colonizations did not influence the diversification rates of primary colonizers. Models currently employed to test ecological opportunity do a poor job of explaining muroid diversity. In addition, the various rate-shift metrics identified different clades, suggesting that caution should be used when only one is applied, and we discuss which methods are most appropriate to address different questions of diversification.

Premise of the Study: Dispersal is a major feature of plant evolution that has many advantages but is not always favored. Wide dispersal, for example, leads to greater seed loss in oceanic-island endemics, and evolution has favored morphologies that limit dispersal. I tested the hypothesis that selection favored limited dispersal on gypsum islands in western North America, where edaphic communities are sparsely vegetated except for a specialized flora that competes poorly with the surrounding flora. •, Methods: I applied a series of comparative phylogenetic approaches to gypsophilic species of Mentzelia section Bartonia (Loasaceae) to investigate the evolution of limited dispersal function in seed wings, which increase primary dispersal by wind. Through these tests, I determined whether narrowed wings were selected for in gypsophilic species. •, Key Results: Gypsophily was derived four to seven times. Seed area was not significantly correlated with gypsophily or wing area. Wing area was significantly smaller in the derived gypsum endemics, supporting the hypothesis in favor of limited dispersal function. A model-fitting approach identified two trait optima in wing area, with gypsum endemics having a lower optimum. •, Conclusions: Evolution into novel ecologies influences morphological evolution. Morphological characters have been selected for limited dispersal following evolution onto gypsum islands. Selection for limited dispersal ability has occurred across animals and plants, both in oceanic and terrestrial systems, which suggests that reduced dispersal ability may be a general process: selection favors limited dispersal if the difference in survival between the habitat of the parent and the surrounding area is great enough.

Objective: Numerous studies in high-risk populations established that variations in infant neuromotor development predict poor cognitive function. It is unclear whether this association is found in the general population. Moreover, previous population-based studies mostly focused on motor milestone achievement., Methods: This study was embedded in the Generation R Study, a population-based cohort in Rotterdam, the Netherlands. Neuromotor development was assessed with an adapted version of Touwen's Neurodevelopmental Examination when infants (1205 males, 1278 females) were on average 12 weeks old (standard deviation 1, range, 9-15 weeks). To measure language function at age 1.5 years, the MacArthur Short Form Vocabulary Checklist was used. At 2.5 years, mothers completed the Language Development Survey and the Parent Report of Children's Abilities measuring language and nonverbal cognitive functioning, respectively., Results: After adjustment for confounders, less optimal neuromotor development, that is, more low tone symptoms, was associated with a delay in receptive language at 1.5 years (odds ratio [OR], 1.18; 95% confidence interval [CI], 1.05-1.34) and in expressive language at multiple time points (OR, 1.11; 95% CI, 1.02-1.21). Higher scores on overall neuromotor development, indicating a less optimal neuromotor development, was associated with an increased risk of a delay in nonverbal cognitive function at 2.5 years (OR, 1.19; 95% CI, 1.05-1.35)., Conclusions: The results of this study suggest that infants with more low tone symptoms, indicating minor deviances from normal neuromotor development, are somewhat more vulnerable to language delays than those infants who do not have these symptoms.

Purpose: The authors tested associations between (a) parent-reported temporary vs. persistent vocabulary delay and (b) parent-reported behavioral/emotional problems in a sample of 5,497 young Dutch children participating in a prospective population-based study., Method: Mothers completed the MacArthur Communicative Development Inventory-Netherlands (Zink & Lejaegere, 2003) at age 18 months and the Language Development Survey (Rescorla, 1989) at age 30 months, with expressive vocabulary delay defined as scores in the lowest 15th age- and gender-specific percentiles. The Child Behavior Checklist (Achenbach & Rescorla, 2000) was completed by mothers when their children were age 18 months and by both parents when their children were age 36 months, from which Internalizing Problems and Externalizing Problems scores were analyzed., Results: All analyses were adjusted for covariates. Expressive vocabulary delay at age 18 months was weakly related to Internalizing Problems scores at age 18 months as well as mother-reported Externalizing and Internalizing Problems scores at age 36 months (the latter for boys only). Expressive vocabulary delay at age 30 months was weakly associated with mother-reported Externalizing and Internalizing Problems scores (the latter for boys only) and father-reported Internalizing Problems scores. Persistent expressive vocabulary delay predicted the highest risk of mother-reported internalizing and externalizing problems at age 36 months., Conclusion: This population-based study showed modest associations between vocabulary delay and behavioral/emotional problems detectable from 18 months onward.

Background: Neuroimaging findings have provided evidence for a relation between variations in brain structures and attention deficit/hyperactivity disorder (ADHD). However, longitudinal neuroimaging studies are typically confined to children who have already been diagnosed with ADHD. In a population-based study, we aimed to characterize the prospective association between brain structures measured during infancy and executive function and attention deficit/hyperactivity problems assessed at preschool age., Methods: In the Generation R Study, the corpus callosum length, the gangliothalamic ovoid diameter (encompassing the basal ganglia and thalamus), and the ventricular volume were measured in 784 6-week-old children using cranial postnatal ultrasounds. Parents rated executive functioning at 4 years using the behavior rating inventory of executive function-preschool version in five dimensions: inhibition, shifting, emotional control, working memory, and planning/organizing. Attention deficit/hyperactivity problems were assessed at ages 3 and 5 years using the child behavior checklist., Results: A smaller corpus callosum length during infancy was associated with greater deficits in executive functioning at 4 years. This was accounted for by higher problem scores on inhibition and emotional control. The corpus callosum length during infancy did not predict attention deficit/hyperactivity problem at 3 and 5 years, when controlling for the confounders. We did not find any relation between gangliothalamic ovoid diameter and executive function or Attention deficit/hyperactivity problem., Conclusions: Variations in brain structures detectible in infants predicted subtle impairments in inhibition and emotional control. However, in this population-based study, we could not demonstrate that early structural brain variations precede symptoms of ADHD., (© 2012 The Authors. Journal of Child Psychology and Psychiatry © 2012 Association for Child and Adolescent Mental Health.)

Aim: General developmental outcome is known to be good in school-aged children who experienced febrile seizures. We examined cognitive and behavioural outcomes in preschool children with febrile seizures, including language and executive functioning outcomes., Method: This work was performed in the Generation R Study, a population-based cohort study in Rotterdam from early fetal life onwards. Information about the occurrence of febrile seizures was collected by questionnaires at the ages of 1, 2, and 3 years. At the age of 3 years, behaviour and emotion were assessed using the Child Behavior Checklist. Information on expressive language development was obtained by the Language Development Survey at the age of 2 years 6 months. To assess executive functioning, parents completed the Behaviour Rating Inventory of Executive Function - Preschool Version when their children were 4 years old. Final analyses were based on 3157 children., Results: No associations were found between febrile seizures and the risk of behavioural problems or executive functioning. In contrast to single febrile seizures, recurrent febrile seizures were significantly associated with an increased risk of delayed vocabulary development (odds ratio 3.22, [95% confidence interval 1.30-7.94])., Interpretation: Febrile seizures are not associated with problem behaviour or executive functioning in preschool children, but the results suggest that children with recurrent febrile seizures might be at risk for delayed language development., (© The Authors. Developmental Medicine & Child Neurology © 2012 Mac Keith Press.)

Background: Post-term birth, defined as birth after pregnancy duration of 42 weeks, is associated with increased neonatal morbidity and mortality. The long-term consequences of post-term birth are unknown. We assessed the association of post-term birth with problem behaviour in early childhood., Methods: The study was performed in a large population-based prospective cohort study in Rotterdam, The Netherlands. Pregnant mothers enrolled between 2001 and 2005. Of a cohort of 5145 children, 382 (7%) were born post-term, and 226 (4%) were born preterm. Parents completed a standardized and validated behavioural checklist (Child Behavior Checklist, CBCL/1.5-5) when their children were 1.5 and 3 years old. We examined the relation between gestational age (GA) at birth, based on early fetal ultrasound examination, and problem behaviour with regression analyses, adjusting for socio-economic and pregnancy-related confounders., Results: A quadratic relationship between GA at birth and problem behaviour indicates that both preterm and post-term children have higher behavioural and emotional problem scores than the term born children. Compared with term born children, post-term born children had a higher risk for overall problem behaviour [odds ratio (OR) = 2.10, 95% confidence interval (CI) = 1.32-3.36] and were almost two and a half times as likely to have attention deficit / hyperactivity problem behaviour (OR = 2.44, 95% CI = 1.38-4.32)., Conclusions: Post-term birth was associated with more behavioural and emotional problems in early childhood, especially attention deficit / hyperactivity problem behaviour. When considering expectant management, this aspect of post-term pregnancy should be taken into account.

Purpose: The authors investigated continuity and discontinuity of vocabulary skills in a population-based cohort in the Netherlands., Method: Mothers of 3,759 children completed the Dutch version of the MacArthur Short Form Vocabulary Checklist (Zink & Lejaegere, 2003) at 18 months and a Dutch translation of the Language Development Survey (Rescorla, 1989) at 30 months. At both ages, expressive vocabulary delay was defined as vocabulary scores <10th age- and gender-specific percentile., Results: Of the children, 85.2% had normal vocabulary development at both ages, 6.2% were "late bloomers," 6.0% had late onset expressive vocabulary delay, and 2.6% had persistent expressive vocabulary delay. Word production and comprehension at 18 months explained 11.5% of the variance in 30-month vocabulary scores, with low birth weight, child age, gender and ethnicity, maternal age and education, and parenting stress explaining an additional 6.2%. Multinomial logistic regression was used to identify biological, demographic, and psychological factors associated with each of the vocabulary delay outcome groups relative to the typically developing group., Conclusions: Although multiple perinatal, demographic, and maternal psychosocial factors significantly predicted vocabulary skills at 30 months, positive predictive value and sensitivity were low. Future studies should address to what extent additional factors, such as brain maturation and genetic influences, can improve the prediction and understanding of continuity and discontinuity of language delay.

Context: Thyroid hormones are essential for neurodevelopment from early pregnancy onward. Yet population-based data on the association between maternal thyroid function in early pregnancy and children's cognitive development are sparse., Objective: Our objective was to study associations of maternal hypothyroxinemia and of early pregnancy maternal TSH and free T(4)(FT(4)) levels across the entire range with cognitive functioning in early childhood., Design and Setting: We conducted a population-based cohort in The Netherlands., Participants: Participants included 3659 children and their mothers., Main Measures: In pregnant women with normal TSH levels at 13 wk gestation (SD = 1.7), mild and severe maternal hypothyroxinemia were defined as FT(4) concentrations below the 10th and 5th percentile, respectively. Children's expressive vocabulary at 18 months was reported by mothers using the MacArthur Communicative Development Inventory. At 30 months, mothers completed the Language Development Survey and the Parent Report of Children's Abilities measuring verbal and nonverbal cognitive functioning., Results: Maternal TSH was not related to the cognitive outcomes. An increase in maternal FT(4) predicted a lower risk of expressive language delay at 30 months only. However, both mild and severe maternal hypothyroxinemia was associated with a higher risk of expressive language delay across all ages [odds ratio (OR) = 1.44; 95% confidence interval (CI) = 1.09-1.91; P = 0.010 and OR = 1.80; 95% CI = 1.24-2.61; P = 0.002, respectively]. Severe maternal hypothyroxinemia also predicted a higher risk of nonverbal cognitive delay (OR = 2.03; 95% CI = 1.22-3.39; P = 0.007)., Conclusions: Maternal hypothyroxinemia is a risk factor for cognitive delay in early childhood.

Ecological opportunity--through entry into a new environment, the origin of a key innovation or extinction of antagonists--is widely thought to link ecological population dynamics to evolutionary diversification. The population-level processes arising from ecological opportunity are well documented under the concept of ecological release. However, there is little consensus as to how these processes promote phenotypic diversification, rapid speciation and adaptive radiation. We propose that ecological opportunity could promote adaptive radiation by generating specific changes to the selective regimes acting on natural populations, both by relaxing effective stabilizing selection and by creating conditions that ultimately generate diversifying selection. We assess theoretical and empirical evidence for these effects of ecological opportunity and review emerging phylogenetic approaches that attempt to detect the signature of ecological opportunity across geological time. Finally, we evaluate the evidence for the evolutionary effects of ecological opportunity in the diversification of Caribbean Anolis lizards. Some of the processes that could link ecological opportunity to adaptive radiation are well documented, but others remain unsupported. We suggest that more study is required to characterize the form of natural selection acting on natural populations and to better describe the relationship between ecological opportunity and speciation rates.

Aim: The aim of this study was to investigate within a population-based cohort of 4384 infants (2182 males, 2202 females) whether fetal growth from early pregnancy onwards is related to infant development and whether this potential relationship is independent of postnatal growth., Method: Ultrasound measurements were performed in early, mid-, and late pregnancy. Estimated fetal weight was calculated using head and abdominal circumference and femur length. Infant development was measured with the Minnesota Infant Development Inventory at 12 months (SD 1.1mo, range 10-17mo). Information on postnatal head size and body weight at 7 months was obtained from medical records., Results: After adjusting for potential confounders and for postnatal growth, faster fetal weight gain from mid- to late pregnancy predicted a reduced risk of delayed social development (odds ratio [OR] 0.82; 95% confidence interval [CI] 0.71-0.95, p=0.008), self-help abilities (OR 0.84; 95% CI 0.73-0.98, p=0.023), and overall infant development (OR 0.65; 95% CI 0.49-0.87, p=0.003). Similar findings were observed for fetal head growth from mid- to late pregnancy., Interpretation: Faster fetal growth predicts a lower risk of delayed infant development independent of postnatal growth. These results suggest that reduced fetal growth between mid- and late pregnancy may determine subsequent developmental outcomes.

The vulnerability for behavioral problems is partly shaped in fetal life. Numerous studies have related indicators of intrauterine growth, for example, birth weight and body size, to behavioral development. We investigated whether fetal size in mid- and late pregnancy is related to infant irritability and alertness. In a population-based birth cohort of 4,255 singleton full-term infants ultrasound measurements of fetal head and abdominal circumference in mid- and late pregnancy were performed. Infant irritability and alertness scores were obtained by the Mother and Baby Scales at 3 months and z-standardized. Multiple linear regression analyses revealed curvilinear associations (inverted J-shape) of measures of fetal size in both mid- and late pregnancy with infant alertness. Fetal size characteristics were not associated with infant irritability. These results suggest that alterations of intrauterine growth affecting infant alertness are already detectable from mid-pregnancy onwards.

As a result of mixed and seemingly contradictory forces in the sociopolitical, economic, and health care environments, credentialing has taken on new momentum and direction in the United States and abroad. The nursing profession, including the American Nurses Credentialing Center, is meeting the challenge through new approaches and partnership endeavors among nursing organizations and with other health care providers and consumer groups.

Previous research has shown that when, under non-reinforced conditions, stimuli are added to S+ and S- stimuli in simultaneous discrimination tasks, transfer between paired stimuli is likely to occur. The present study examined whether this procedure also leads to the formation of conditional relations between paired stimuli. In Experiments 1, 2, and 3, normal pre-school children were trained on a simultaneous discrimination task with A1 reinforced and A2 not reinforced (A1+/A2-). Then they received two tests (no programmed consequences): one with B stimuli superimposed on the A stimuli (A1B1/ A2B2), and one with B stimuli only (B1/B2). Subjects who selected A1B1 and B1 also received conditional discrimination tests: one with B1 or B2 as samples and A1 and A2 as comparisons (B-A), and one in which the functions of these stimuli were reversed (A-B). Intellectually impaired adults and normal adults served in Experiments 4 and 5, respectively. These experiments were basically the same except that the subjects were also given the opportunity to demonstrate transfer from B to C via BC (B1C1/B2C2 and C1/C2 tests). Most children (75%) and intellectually impaired adults (75%) treated the conditional discrimination probe tasks as simple discriminations and typically selected the trained and derived S+ stimuli. The remaining children, intellectually impaired adults, and all normal adults related all directly and indirectly linked stimuli of the same functions conditionally to one another (A-B, B-C, A-C, and vice versa). The present findings suggest that, as humans develop, conditional stimulus relations may emerge from tasks and stimulus configurations that are increasingly remote from traditional conditional discrimination tasks.

This study reports two experiments that first taught preschool children identity-matching to compound sample and compound comparison stimuli. A compound stimulus consisted of a colour and a form superimposed on one another. Test sessions assessed whether children related the form and colour elements of a particular compound stimulus. The test for this was matching to sample in which an arbitrary conditional discrimination was required. A majority of the children selected the correct colour comparison in the presence of each form sample. The children also showed the reverse sample-comparison relations: they matched form comparisons to the corresponding colour samples, respectively. In the context of these arbitrary relations, new colours were paired with the form elements of the samples (Experiment 1), and new form elements were paired with the colour elements of the comparisons (Experiment 2). Subsequent tests assessed whether the new stimulus elements had control over responding when presented as single samples or comparisons. Test results showed that most subjects were able to relate the new stimulus elements to the corresponding colour and form elements, respectively. The study demonstrated that matching to compound stimuli in training and testing conditions may generate conditional relations between the individual stimulus elements.