bluuebunny/crossref_metadata_2025 huggingface dataset:
Miocene hominoid biogeography: pulses of dispersal and differentiation
Authors: Folinsbee Kaila E. , Brooks Daniel R.
Published: February 2007

Aim To test the hypothesis that the ancestor of the hominines (African apes and humans) had an African origin by comparing the historical biogeographical patterns of hominoids with those of two other large land mammal clades, namely the hyaenids and proboscideans.

Location Global, primarily the Old World over the last 25 Myr (Miocene to present).

Methods Creation of a general area cladogram usingpact, a new method for generating area cladograms, and interpretation of general and clade‐specific speciation events involving hominoids, proboscideans and hyaenids.

Results The analysis of the areas usingpactreveals both general patterns and clade‐specific exceptions to these patterns. All three groups share a general episode of species formation in Africa in the early Miocene, followed by ‘out of Africa’ expansion into Europe, Asia and North America, and a second general episode of species formation in Asia in the mid‐Miocene, followed by ‘out of Asia’ expansion into Africa, Europe and North America. Finally, there were two additional ‘out of Africa’ events during the late Miocene and into the Pliocene, the last one setting the stage for the emergence and spread ofHomo. In addition to these shared episodes of vicariance and dispersal, each group exhibits clade‐specific within‐area and peripatric speciation events.

Main conclusions The complex history of dispersal and speciation over large areas exhibited by hominoids is part of a more general history of biotic diversification by taxon pulses. Refining this scenario will require the integration of additional clades from the same areas and times, as well as more detailed palaeoclimatological, palaeoenvironmental and geological evidence.
Plant strategy theories: a comment on Craine (2005)
Authors: GRIME J. PHILIP
Published: February 2007

It is suggested that arguments concerning the nature of primary plant strategies could have been resolved more rapidly by reference to older literature relating to the behaviour of solutes in the rhizosphere and by more active programmes of plant trait screening.

The critique of CSR theory in Craine (2005) is rejected largely on the basis that it misunderstands the role of fundamental and proximal controls on vegetation composition (sensu Welden & Slauson 1986).

The ‘way forward’ advocated in Craine (2005) is flawed in its exclusive reliance on competition experiments. Recent progress in community and ecosystem ecology is strongly related to an increasing recognition of the declining importance of competition in unproductive or heavily disturbed environments.
Resource competition and plant traits: a response to Craine et al. 2005
Authors: TILMAN DAVID
Published: February 2007

Resource competition theory incorporates the mechanisms that underlie consumer–resource interactions and the trade‐offs that constrain these mechanisms. Contrary to assertions by Craine, the concept of R* as the measure of resource reduction and the predictor of resource competition has not changed since it was proposed more than two decades ago.

Resource reduction, as summarized in R*, is readily observed. Soil concentrations of nitrate and water are decreased by plant uptake, and are lowered to different levels by different species. Tests have shown R* theory to correctly predict competitive outcomes for a variety of organisms and ecosystems.

Consumer‐resource mechanisms are a building block for theories that incorporate other trade‐offs faced by plants, such as those between competitive ability and dispersal.

Numerous plant traits interactively determine R* in a manner predictable from trait‐based resource competition theory. The same traits shown by comparative research to be associated with plant dominance in low‐nutrient habitats give lower R* values, greater predicted competitive ability and greater predicted abundances in nutrient‐limited habitats.

Plant ecology needs closer links between analytical theory, observations and experiments. Simple verbal theories can generate novel ideas but the logical implications of such scenarios are best explored using the rigorous logic of mathematics. Predictions of theory can then be tested via experiments and comparative studies.
Plant strategy theories: replies to Grime and Tilman
Authors: CRAINE JOSEPH M.
Published: February 2007

In response to my essay review that attempted to reconcile the plant strategy theories of Grime and Tilman, Grime rejects five tenets that I had identified in his theories that were incomplete, inconsistent, or incorrect.

Grime fails to adequately address three of these concerns. Regarding the other concerns, it is clear that the concept of relative importance needs to be developed further. For example, if both competition and the stress of low nutrient supplies can remove species from a given environment, then neither can be elevated over the other without being tautological.

With regards to Tilman's response, it is clear that it will be important to be explicit about the relationship between data and models. At times, Tilman is neither evaluating individual models with a Popperian approach nor comparing contrasting models in a Bayesian fashion. As it stands, it is unclear what is required for Tilman to reject R* as the mechanism of competition, or whether it passes some undetermined threshold of acceptability.

Comparing concentration reduction to supply pre‐emption as the mechanism of competition recommends supply pre‐emption on many fronts. Supply pre‐emption better represents the movement of nutrients in soil solution. Assuming well‐mixed soil solutions can theoretically lead to improper prediction of competitive outcomes. Empirically, there are examples where R* does not predict outcomes for competition for nutrients, and supply pre‐emption appears to generate metrics (root length density) that are equivalent if not better than concentration reduction (R*) at explaining these outcomes.

The next plant strategies paradigm will not be a result of choosing either Grime's or Tilman's theories, but represent a synthesis of the two sets of theories while also incorporating novel concepts and research. I agree with Tilman that more research is needed in understanding mechanisms of coexistence, but there still remains large gaps in our understanding of plant traits and growth that limit our understanding of competition for nutrients and will likely constrain our understanding of coexistence even more.
Measuring the components of competition along productivity gradients
Authors: WILSON MARK V.
Published: February 2007

Controversy surrounds the measurement of competition intensity. Moreover, when biomass varies systematically along productivity and other environmental gradients, common indices of competitive outcome mask important ecological interactions.

This study presents two indices derived from how neighbours interact with target plants. The first, relative crowding, increases directly with the abundance of neighbours present and decreases inversely with the potential size and vigour of the target plant itself. The second, interaction strength, is the integral of suppression of the target by neighbours over the range of neighbour abundance. Relative crowding and interaction strength are derived independently, but when multiplied produce the commonly used relative competitive index, showing the biological underpinnings of the relative competition index in terms of crowding and strength of interaction. Since the new indices of relative crowding and interaction strength explicitly account for the amount of neighbour biomass, they serve as a valid method to track the effects of changing habitat conditions on the components of competition.

The new indices are applied to three published data sets. In each case, relative crowding increased with standing crop. In one case competition was reported as unchanged along a productivity gradient, whereas the new indices show that relative crowding and interaction strength both had significant patterns, but their effects were counteracting. These results do not fit current theories of competition. Further empirical studies are needed to see if competition theory needs revision.

Separating the mechanisms of competition into relative crowding and strength of interaction reveals previously hidden patterns that help bring to light underlying processes of competition along productivity gradients.
Clinical evaluation of abutment teeth of removable partial denture by means of the Periotest method
Authors: JORGE J. H. , GIAMPAOLO E. T. , VERGANI C. E. , MACHADO A. L. , PAVARINA A. C. , CARDOSO DE OLIVEIRA M. R.
Published: February 2007

Summary  Prosthodontics should be one of the means of establishing conditions for the maintenance of periodontal health. The forces applied to the abutment teeth and their effects are very important considerations in the design and construction of the removable partial dentures. This 6‐month follow‐up clinical study evaluated the degree of mobility of abutment teeth of distal extension and tooth supported removable partial dentures by using Periotest. Two types of clasp design were selected for evaluation. In cases with unilateral and bilateral distal‐extension, a clasp design including a T clasp of Roach retentive arm, a rigid reciprocal arm and a mesial rest were used. For the abutments of tooth‐supported removable partial dentures, a second clasp design with a cast circumferential buccal retentive arm, a rigid reciprocal clasp arm and a rest adjacent to the edentulous ridges was selected. A total of 68 abutment teeth was analysed. Periotest values were made at the time of denture placement (control) and at 1, 3 and 6 months after the denture placement. The statistical analysis was performed using Friedman test. All analysis was performed at a 0·05 level of significance. The results revelled that no significant changes in tooth mobility were observed during the 6‐months follow‐up (P > 0·05). In conclusion, our findings suggest that adequate oral hygiene instructions, careful prosthetic treatment planning and regular recall appointments play an important role in preventing changes in abutment tooth mobility caused by removable partial denture placement.
Clinical, psychiatric and manometric profile of cyclic vomiting syndrome in adults and response to tricyclic therapy1
Authors: Namin F. , Patel J. , Lin Z. , Sarosiek I. , Foran P. , Esmaeili P. , Mccallum R.
Published: February 2007

Abstract  Our goal was to investigate 31 adult patients (mean age 29 years, range 18–62 years) meeting Rome II criteria for cyclic vomiting syndrome (CVS). All subjects completed a clinical questionnaire, a Hamilton Rating Scale for Anxiety (HAM‐A) and Zung Depression Inventory. Gastric emptying time was assessed in 30 subjects and electrogastrogram (EGG) in 11 between acute attacks. Twenty‐seven patients treated with amitriptyline completed a follow‐up questionnaire. The mean age of onset of the patients was 30 years (range 14–53 years) and cycles of nausea and vomiting were accompanied by often‐severe epigastric and diffuse abdominal pain. A typical attack ranged from 1 to 14 days, with the majority being 4–6 days. The HAM‐A revealed that 84% had an anxiety disorder, and based on Zung Depression Inventory 78% suffered from mild‐to‐severe depression. Only 4 (13%) patients reported migraine, but 14 had a family history of migraine. Gastric emptying time was rapid in 23 (77%), normal in 4 and delayed in 3. The EGG was abnormal in 7 of 11 patients, with 4 having tachygastria. Of 13 patients using marijuana, 7 had symptom relief, while 2 had resolution of CVS after stopping use. The overall treatment experience in the 24 patients receiving amitriptyline up to 1 mg kg−1 day−1 for at least 3 months indicated that 93% had decreased symptoms and 26% achieved full remission. Cyclic vomiting syndrome in adults has the following hallmarks: prominence of accompanying abdominal pain and increased prevalence of anxiety and depression, rapid gastric emptying and tachygastric EGG, and successful suppression of attacks by chronic amitriptyline therapy.
A double‐blind, randomized, placebo‐controlled trial of itopride (100 and 200 mg three times daily) on gastric motor and sensory function in healthy volunteers
Authors: Choung R. S. , Talley N. J. , Peterson J. , Camilleri M. , Burton D. , Harmsen W. S. , Zinsmeister A. R.
Published: February 2007

Abstract  Itopride, a dopamine D2 antagonist and acetylcholinesterase inhibitor, significantly improved symptoms in patients with functional dyspepsia in one phase II randomized trial. However, the mechanisms by which itopride may improve symptoms are unknown. We aimed to compare the effects of two doses of itopride and placebo on gastric volumes, gastric emptying, small bowel transit and satiation in female and male healthy volunteers. Randomized, double‐blind, placebo‐controlled study evaluated gastric function before and after 7 days of itopride 100 mg (n = 16) or 200 mg (n = 15) or placebo (n = 15) t.i.d. Validated methods were used to study gastric accommodation (single photon emission computed tomography), gastric emptying and orocecal transit and satiation postnutrient challenge. The three arms were comparable with regard to age, gender and body mass index. There were no statistically significant effects of itopride on gastric emptying, orocecal transit, fasting gastric volume, maximum tolerated volume or aggregate symptom score with nutrient drink challenge. Postprandial (PP) change in gastric volume differed in the three groups (P = 0.019): 625[±28 (SEM)], 555(±26) and 512(±33) in placebo, itopride 100 and 200 mg groups, respectively. In healthy subjects, itopride reduced total PP gastric volume without accelerating gastric emptying or significantly altering gastric motor and sensory function in healthy individuals.
Upper sphincter function during transient lower oesophageal sphincter relaxation (tLOSR); it is mainly about microburps
Authors: Pandolfino J. E. , Ghosh S. K. , Zhang Q. , Han A. , Kahrilas P. J.
Published: February 2007

Abstract  Transient lower oesophageal sphincter relaxations (tLOSRs) are both a dominant mechanism of reflux and an element of the belch reflex. This study aimed to analyse the interplay between reflux and upper oesophageal sphincter (UOS) activity during meal‐induced tLOSRs. Fifteen normal subjects were studied with a solid‐state high‐resolution manometry assembly positioned to record from the hypopharynx to the stomach and a catheter pH electrode 5 cm above the LOS. Subjects ate a 1000‐calorie high‐fat meal and were monitored for 120 min in a sitting posture. The relationship among tLOSRs, common cavities, pressure changes within the oesophagus and UOS contractile activity were analysed. A total of 218 tLOSRs occurred among the 15 subjects. The majority (79%) were coupled with UOS relaxation and 84% (145/173) of these occurred in association with a common cavity. Upper oesophageal sphincter relaxation was usually preceded by a pressure change in the oesophagus; however, some relaxations (16%) occurred without a discernable increase in pressure or before the pressure increase began. Acid reflux did not appear to play a role in determining UOS response to tLOSRs. The majority of post‐prandial tLOSRs were associated with brief periods of UOS relaxation, likely permissive of gas venting (microburps). Intraoesophageal pressure changes likely modulate this UOS response; however, an anticipatory characteristic was evident in some subjects. Whether or not GORD patients with extra‐oesophageal symptoms exhibit an exaggeration of the UOS relaxation response during reflux is yet to be determined.
Inhibitory effects of sildenafil on gastric motility and gastric slow waves in dogs
Authors: Zhu H. , Xu X. , Chen J. D. Z.
Published: February 2007

Abstract  The aim of this study was to investigate the effects of sildenafil on gastric motility and gastric slow waves in dogs. The study was performed in healthy dogs and composed of three experiments. The first experiment was designed to study the effects of sildenafil on gastric emptying and gastric slow waves. The second experiment was used to investigate the effects of sildenafil on gastric tone. The third experiment was used to study the effects of sildenafil on postprandial antral contractions. (i) Sildenafil did not alter gastric emptying of liquid. (ii) Sildenafil had no effects on dominant frequency and percentage of normal gastric slow waves. The dominant power of gastric slow waves was, however, significantly reduced with sildenafil (P < 0.02). (iii) Fasting gastric volume with sildenafil was significantly higher than that at baseline (P < 0.0005) or in the control session (P < 0.002). However, the postprandial gastric volume was not altered with sildenafil. (iv) Sildenafil inhibited gastric antral motility. The contraction index was 338.5 ± 39.99 at baseline and 122.5 ± 20.3 after the injection of sildenafil (P = 0.003). Sildenafil inhibits fundic tone and antral motility but does not seem to delay gastric emptying of liquid in dogs. The amplitude but not the frequency or regularity of the gastric slow wave is inhibited by sildenafil.
Obestatin – a ghrelin‐associated peptide that does not hold its promise to suppress food intake and motility
Authors: Gourcerol G. , Taché Y.
Published: February 2007

Abstract  Ghrelin is a gut peptide well established to induce prokinetic and appetite stimulatory actions. Obestatin is a novel 23‐amino acid peptide derived from the processing of the ghrelin gene. The peptide name was in keeping with its initially reported actions to suppress food intake and digestive motility and to antagonize ghrelin's stimulatory effect through interaction with the orphan GPR‐39 receptor. However, subsequently, these findings have been questioned because obestatin actions to reduce food intake and to inhibit gastrointestinal (GI) motility in vivo and in vitro have not been reproduced by several groups. Furthermore, while GPR‐39 appears to be involved in gut motor functions, convergent reports showed that obestatin is not the cognate ligand for this receptor. In light of recent controversy over the effects of obestatin, the present findings from De Smet et al. provides additional evidence that obestatin does not influence food intake and GI motility in vivo and in vitro. Taken together, existing reports curtail the initial promise that obestatin is a new regulator of appetite and digestive motility. Therefore, it is proposed to rename obestatin as ghrelin‐associated peptide.
Effect of maternal asthma on birthweight and neonatal outcome in a British inner‐city population
Authors: Clark Julia M. , Hulme Emma , Devendrakumar Vijaya , Turner Mark A. , Baker Philip N. , Sibley Colin P. , D’Souza Stephen W.
Published: February 2007

During pregnancy, asthma‐related alterations in placental function and the maternal immune system, and reduced growth affecting female but not male fetuses have been reported in a study of selected Australian women. The objective of this study was to evaluate the effect of asthma management, declared during pregnancy, on birthweight and neonatal outcome at an inner‐city hospital in England. Between June 2001 and December 2003, women at antenatal clinics were questioned about asthma (n = 10 983). Women with asthma and singleton uncomplicated pregnancies ending at term were selected (n = 718), with non‐asthmatic controls (n = 718).

Among asthmatic women using inhaled steroids and bronchodilators (n = 170), 43% of the newborn boys had birthweights <10th centile, compared with 27% of controls (P = 0.011; OR 2.51 [95% CI: 1.52, 4.14]). For girls, the proportions were 28% and 27%. In women using bronchodilators only (n = 178) or those declaring no treatment (n = 370), birthweights were not significantly reduced. Taking account of smoking, ethnicity, gestational age and parity, there was a mean birthweight reduction with inhaled steroids and bronchodilators of 118 g [95% CI 36.0, 199.0 g] compared with the control group. There was no interaction between the effect of asthma treatment and infant gender. Infants of asthmatic women in the three subgroups who required intensive care were more likely to exhibit transient tachypnoea of the newborn than infants of control women (P < 0.005). In our population‐based sample, the risk of low birthweight among asthmatic women did not depend on infant gender, while neonatal respiratory morbidity remains a significant health issue in boys and girls.
Rates of caesarean section: analysis of global, regional and national estimates
Authors: Betrán Ana P. , Merialdi Mario , Lauer Jeremy A. , Bing‐Shun Wang , Thomas Jane , Van Look Paul , Wagner Marsden
Published: February 2007

Rates of caesarean section are of concern in both developed and developing countries. We set out to estimate the proportion of births by caesarean section (CS) at national, regional and global levels, describe regional and subregional patterns and correlate rates with other reproductive health indicators. We analysed nationally representative data available from surveys or vital registration systems on the proportion of births by CS. We used local non‐parametric regression techniques to correlate CS with maternal mortality ratio, infant and neonatal mortality rates, and the proportion of births attended by skilled health personnel. Although very unevenly distributed, 15% of births worldwide occur by CS. Latin America and the Caribbean show the highest rate (29.2%), and Africa shows the lowest (3.5%). In developed countries, the proportion of caesarean births is 21.1% whereas in least developed countries only 2% of deliveries are by CS. The analysis suggests a strong inverse association between CS rates and maternal, infant and neonatal mortality in countries with high mortality levels. There is some suggestion of a direct positive association at lower levels of mortality. CS levels may respond primarily to economic determinants.
A continuous‐scale measure of child development for population‐based epidemiological surveys: a preliminary study using Item Response Theory for the Denver Test
Authors: Drachler Maria de Lourdes , Marshall Tom , De Carvalho Leite José Carlos
Published: February 2007

A method for translating research data from the Denver Test into individual scores of developmental status measured in a continuous scale is presented. It was devised using the Denver Developmental Screening Test (DDST) but can be used for Denver II. The DDST was applied in a community‐based survey of 3389 under‐5‐year‐olds in Porto Alegre, Brazil. The items of success were standardised by logistic regression on log chronological age. Each child’s ability age was then estimated by maximum likelihood as the age in this reference population corresponding to the child’s success and failures in the test. The score of developmental status is the natural logarithm of this ability age divided by chronological age and thus measures the delay or advance in the child’s ability age compared with chronological age. This method estimates development status using both difficulty and discriminating power of each item in the reference population, an advantage over scores based on total number of items correctly performed or failed, which depend on difficulty only. The score corresponds with maternal opinion of child developmental status and with the 3‐category scale of the DDST. It shows good construct validity, indicated by symmetrical and homogeneous variability from 3 months upwards, and reasonable results in describing gender differences in development by age, the mean score increasing with socio‐economic conditions and diminishing among low‐birthweight children. If a standardised measure of development status (z‐scores) is required, this can be obtained by dividing the score by its standard deviation. Concurrent and discriminant validity of the score must be examined in further studies.
Maternal sensitivity concerning aetiological research into childhood cancer: results of preliminary focus groups
Authors: Linet Martha S. , Byrne Julianne , Willis Gordon B. , Wacholder Sholom , Forman Michele R.
Published: February 2007

We and others have postulated that modifications to epidemiological methods and tools could improve understanding of childhood cancer aetiology. We describe features of paediatric cancer that influence study design and data collection strategies, and examine determinants of the reproducibility and accuracy of mothers' responses to questionnaires, which are the primary source of risk factor information. Two focus group sessions with mothers of children with acute lymphoblastic leukaemia (ALL) and two with mothers of children with brain tumours were conducted to explore: the optimal time of day, method of administration, and location for the interview; the availability of alternative data sources; the interval between paediatric cancer diagnosis and epidemiological interview; and other features which may affect maternal interview responses.

Mothers of children with both types of cancer preferred being interviewed at home during the evening and were willing to provide complete access to their offsprings' medical records. Emotional, socio‐economic and perhaps cultural differences between the groups of mothers were exemplified by the willingness of mothers of children with ALL to participate in epidemiological interviews earlier in their child's treatment course and to provide greater access to maternal reproductive history records compared with mothers of children with brain tumours. Parental concerns about the difficult disease and treatment course of children with brain tumours were a key element in their decision to defer participating in epidemiological interviews for many months after their child's cancer diagnosis. We conclude that the focus group approach can contribute to a broad strategy for improving questionnaires and methods for conducting paediatric cancer epidemiological research.
Vaginal birth after caesarean delivery: does maternal age affect safety and success?
Authors: Srinivas Sindhu K. , Stamilio David M. , Sammel Mary D. , Stevens Erika J. , Peipert Jeffrey F. , Odibo Anthony O. , Macones George A.
Published: February 2007

To estimate maternal age effects on the rates of vaginal birth after caesarean delivery (VBAC), the related maternal complications and patient election to attempt VBAC, we conducted a secondary analysis of a retrospective cohort study of women who were offered VBAC from 1996 to 2000 in 17 community and university hospitals. We used bivariable and multivariable analyses to assess the association between maternal age and the study outcomes. A total of 25 005 patients were included, of whom 13 706 (54.81%) elected to attempt VBAC. After controlling for several confounding variables, using ages 21–34 years as the referent group, women aged 15–20 years were 27% less likely to have a failed VBAC attempt (OR = 0.73 [0.62, 0.87], P < 0.001). Analysing maternal age as a dichotomous variable, women who were of advanced maternal age (≥35 years) were more likely to experience an unsuccessful trial of labour (OR = 1.14 [1.03, 1.25], P = 0.009). In addition, women ≥35 years of age had 39% more risk of experiencing one of the VBAC‐related operative complications (OR = 1.39 [1.02, 1.89], P = 0.039). As women increase in age, they are less likely to attempt VBAC and more likely to have an unsuccessful labour trial. While teenage patients do not appear to be at increased risk for VBAC‐related complications, patients of advanced maternal age do show an increase in composite VBAC‐related operative complication rates.
Breast feeding and mental and motor development at 12 months in a low‐income population in northeast Brazil
Authors: Eickmann Sophie Helena , De Lira Pedro Israel Cabral , Lima Marilia de Carvalho , Coutinho Sonia Bechara , Teixeira Maria de Lourdes Perez Diaz , Ashworth Ann
Published: February 2007

The aim of this prospective study was to investigate the association between breast feeding and mental and motor development at age 12 months, controlling for comprehensive measures of the child's socio‐economic, maternal and environmental background, and nutritional status. A cohort of 205 infants born during May–August 2001 in a poor area in the interior of the State of Pernambuco was enrolled, of whom 191 were tested at age 12 months with the Bayley Scales of Infant Development II, and in whom breast‐feeding status was measured at days 1, 10, 30, 60, 90, 120, 150, 180, 270 and 360. After adjusting for potential confounders, full breast feeding (i.e. exclusive or predominant) at 1 month was associated with a small but significant benefit in mental development (+3.0 points, P = 0.02) compared with partial or no breast feeding. No additional advantage in mental development was found with longer durations of full breast feeding. Full breast feeding at 1 month was associated with improved behaviour for two of 10 ratings tested: initiative with tasks (P = 0.003) and attention (P = 0.02). No association between breast feeding and motor development was found.
Determinants of developmental delay in infants aged 12 months
Authors: Slykerman Rebecca F. , Thompson John M. D. , Clark Phillipa M. , Becroft David M. O. , Robinson Elizabeth , Pryor Jan E. , Wild Chris J. , Mitchell Edwin A.
Published: February 2007

The aim of this study was to determine which demographic, maternal, obstetric and postnatal variables were associated with achievement of developmental milestones at the age of 12 months in term infants. Mothers and babies were enrolled in the Auckland Birthweight Collaborative Study shortly after birth. All infants were full term (gestation ≥ 37 weeks). Approximately half of the sample were small for gestational age (SGA = birthweight ≤ 10th percentile), and half were appropriate for gestational age (AGA = birthweight > 10th percentile). A maternal interview was conducted soon after birth. Phase 2 of the study occurred 12 months later when mothers were sent a postal questionnaire requesting information about the child's health and development during the first year of life using the Denver Prescreening Developmental Questionnaire. Seven hundred and forty‐four (85.4%) European mothers returned the postal questionnaire.

SGA children were not at increased risk of developmental delay at 12 months of age. In a sample representative of New Zealand European children, after adjustment for the effects of potential confounders, maternal smoking during pregnancy (OR = 2.1 [95% CI 1.1, 4.0]), maternal smoking during the first year of life (OR = 1.9 [95% CI 1.0, 3.8]) and low levels of satisfaction with parenting (OR = 2.4 [95% CI 1.1, 5.2]) were associated with significantly increased risk of developmental delay. In the subgroup of SGA children, maternal smoking during pregnancy (OR = 2.9 [95% CI 1.4, 6.2]), high levels of stress associated with parenting (OR = 2.2 [95% CI 1.2, 4.0]), and low levels of satisfaction with parenting (OR = 4.3 [95% CI 1.3, 13.5]) were significantly associated with developmental delay after adjustment for the effects of potential confounders. In conclusion, maternal and postnatal factors were better predictors of developmental delay than demographic variables.
A public health collaboration for the surveillance of autism spectrum disorders
Authors: Rice Catherine E. , Baio Jon , Van Naarden Braun Kim , Doernberg Nancy , Meaney F. John , Kirby Russell S. ,   ADDM Network
Published: February 2007

Autism spectrum disorders (ASDs) represent a range of behavioural phenotypes defined by impaired development in social interaction, communication, imagination, and range of interests or behaviours. The aetiology and epidemiology of these serious developmental disabilities (DDs) are poorly understood. Estimates of the population prevalence of ASDs have varied widely within the US and abroad, with increasing estimates in most of the recent studies. In an effort to improve our understanding of the prevalence, population characteristics and public health impact of these conditions, the Centers for Disease Control and Prevention has funded a multi‐site surveillance network for ASDs and other DDs that consists of programmes known as the Autism and Developmental Disabilities Monitoring (ADDM) network which conducts surveillance activities and the Centers for Autism and Developmental Disabilities Research and Epidemiology (CADDRE) which also conducts surveillance in addition to special research studies related to the ASDs. This collaboration will be referred to hereafter as the ADDM Network. The ADDM Network is implementing a multiple‐source surveillance programme to determine population prevalence and characteristics of ASDs and other DDs. This paper describes the collaborative efforts and explains the methods in developing this coordinated public health surveillance network to provide an ongoing source of high‐quality data on ASDs.
Clp protease controls chlorophyll b synthesis by regulating the level of chlorophyllide a oxygenase
Authors: Nakagawara Eiki , Sakuraba Yasuhito , Yamasato Akihiro , Tanaka Ryouichi , Tanaka Ayumi
Published: February 2007

Chlorophyll b is one of the major light‐harvesting pigments in green plants and it is essential for optimal light harvesting. Chlorophyll b is synthesized from chlorophyll a by chlorophyllide a oxygenase (CAO) which consists of A, B and C domains. Previously, we demonstrated that the C domain alone has a catalytic function, while the A and B domains control the level of CAO protein in response to chlorophyll b accumulation. We hypothesized that the accumulation of chlorophyll b triggers the proteolytic degradation of CAO. In this study, in order to gain further insight into this regulatory mechanism we screened for mutants that have defects in the control of CAO accumulation. Seeds from a transgenic line of Arabidopsis which overexpressed a CAO–GFP fusion were mutagenized and their progenies were screened by laser‐scanning confocal microscopy for mutants showing an elevated level of GFP fluorescence. One particular mutant (dca1) exhibited stronger GFP fluorescence and accumulated a GFP–CAO fusion protein at a higher level. Concomitantly, the chlorophyll a to b ratio decreased in this mutant. The mutation in the dca1 mutant was mapped to the ClpC1 gene, thereby indicating that a chloroplast Clp protease is involved in regulating chlorophyll b biosynthesis through the destabilization of CAO protein in response to the accumulation of chlorophyll b.
Association of polymorphic extracellular domains of MICA with cervical cancer in northeastern Thai population
Authors: Jumnainsong A. , Romphruk A. V. , Jearanaikoon P. , Klumkrathok K. , Romphruk A. , Luanrattanakorn S. , Leelayuwat C.
Published: February 2007

Cancer of the cervix is one of the common cancers among women worldwide. The primary risk factor of cervical cancer is the high‐risk group human papillomavirus infection. Host genetic factors should also be involved. Major histocompatibility complex class I chain related A (MICA), a ligand to the natural killer cell receptor group (NKG)2D receptor relevant to immune surveillance, was investigated as a potential candidate. MICA is highly polymorphic. Although the data were limited regarding functional polymorphism, it is conceivable that polymorphism of MICA may contribute to different degree of immune activation caused by different NKG2D‐binding affinity, acting as a susceptible factor for development of cervical cancer. In this study, we have developed a polymerase chain reaction–sequence‐specific primer technique defining most of MICA alleles with a total of 41 primer mixes. This set of primers could especially discriminate MICA*045 (formerly 052), a common allele in northeastern Thai population, from MICA*00701, a common allele in Caucasian population. Based on the distribution of MICA in northeastern Thai population, only 27 primer mixes were required to screen the MICA polymorphisms in this population. This set of primers was used for MICA typing of 100 samples of cervical cancer compared with 94 samples of healthy northeastern Thai females (NETF). Thirteen alleles or groups of alleles were identified in these samples. Common alleles in our population were MICA*00801(027,048)/0803, MICA*010 and MICA*00201(020, 023, 050)/30/41. Statistically significant differences were not observed in the distributions of MICA alleles between different stages of patients and the control group. However, there were particular residues that were negatively associated with cervical cancer, suggesting active MICA motifs in immune activation.
Temperature‐sensitive anthocyanin production in flowers of Plantago lanceolata
Authors: Stiles Elizabeth A. , Cech Nadja B. , Dee Stacy M. , Lacey Elizabeth P.
Published: February 2007

Flower color in the weedy perennial Plantago lanceolata is phenotypically plastic. Darker flowers are produced at cooler ambient temperatures, and circumstantial evidence suggests that this is adaptive. The goal of this project was to investigate the chemical basis for the color plasticity. To test the hypothesis that increased anthocyanin production at low temperatures underlies the plasticity, extracts of P. lanceolata flowers produced at warm and cool temperatures were analyzed using UV/visible spectrophotometry coupled with mass spectrometry. Mass spectrometry allowed us to compare relative abundances of individual anthocyanins. Seventeen anthocyanins, derived from both cyanidin and delphinidin branches of the anthocyanin biosynthetic pathway, were detected. Most of these significantly increased in abundance under cool conditions. Genotypes differed significantly in anthocyanin levels and in their sensitivity to temperature change. Genotypes that showed greater floral color plasticity tended to show also greater temperature sensitivity with respect to anthocyanin production. Data suggest that the temperature regulation of the anthocyanin biosynthetic pathway occurs both upstream and downstream of the divergence of the cyanidin and delphinidin branches. The degree of temperature sensitivity, i.e. phenotypic plasticity, appears to be controlled downstream, whereas the overall temperature effect appears to be controlled upstream.
Functional screening of salt stress‐related genes fromThellungiella halophilausing fission yeast system
Authors: Liu Ning , Chen An‐Ping , Zhong Nai‐Qin , Wang Fang , Wang Hai‐Yun , Xia Gui‐Xian
Published: February 2007

Salinity stress is one of the most serious factors limiting plant growth and threatening global food security. Identification of salt tolerance relevant genes from halophytes can provide more insights into the determinants of salt stress tolerance in plants. In this study, functional screening of genes for the salinity tolerance inThellungiella halophila(salt cress) was carried out using fission yeast as a host organism. A cDNA library of the salt cress, constructed in the yeast vector under the control of the inducible promoter nmt1, was transformed into the fission yeastSchizosaccharomyces pombe.Transgenic yeast cells that showed enhanced salt tolerance were selected. A total of 69 such clones were identified from 106of yeast transformants by one‐time screening. Functional assignment indicates that a large percentage (81%) of these cDNAs encode for homologues of proteins that are known to have roles in plant salt tolerance, while the other portion (19%) codes for unknown proteins. Among the proteins encoded by the known functional genes, the regulatory proteins account for a relatively higher proportion. Northern blot analysis showed that the expression of some isolated genes was salt stress inducible, whereas that of the others was constitutive. These results indicate that fission yeast is a simple and efficient system for functional and large‐scale identification of salt tolerance‐related genes from other organisms.
Genomic changes associated with somaclonal variation in banana (Musa spp.)
Authors: Oh Thomas J. , Cullis Margaret A. , Kunert Karl , Engelborghs Iris , Swennen Rony , Cullis Christopher A.
Published: February 2007

The molecular basis of somaclonal variation is not precisely known, but both genetic and epigenetic mechanisms have been proposed. The available evidence points toward the existence of labile portions of the genome that can be modulated when the cells undergo the stress of tissue culture. Therefore, the hypothesis that there are identifiable and predictable DNA markers for the early diagnosis of somaclonal variation has been tested. Representational difference analysis was used to isolate unique fragments of DNA (difference products) between visible culture‐induced off‐type and normal banana plants. Markers generated from six difference products differentiated between some of the off‐type and normal pairs. The genomic region around one of these difference products has been extensively characterized and has a high degree of polymorphism, with variation in up to 10% of the nucleotides sequenced in the region. This same region has been shown to vary in other pairs of off‐type and normal banana plants derived from tissue culture as well as in plants propagated commercially in vitro. The data are consistent with the hypothesis that there is at least one particularly labile portion of the genome that is especially susceptible to the stress imposed during tissue culture and that is associated with higher rearrangement and mutation rates than other portions of the genome. Consequently, the regions that are reported here have the potential to be used as early detection tools for identifying somaclonal variants.
The effects of genetic manipulation of putrescine biosynthesis on transcription and activities of the other polyamine biosynthetic enzymes1
Authors: Page Andrew F. , Mohapatra Sridev , Minocha Rakesh , Minocha Subhash C.
Published: February 2007

We have studied the effects of overproduction of putrescine (Put) via transgenic expression of a mouse ornithine decarboxylase (ODC) gene on the expression of native genes for four enzymes involved in polyamine biosynthesis in hybrid poplar (Populus nigra×maximowiczii) cells. An examination of the transcript levels of arginine decarboxylase (ADC), ODC, S‐adenosylmethionine decarboxylase (SAMDC) and spermidine synthase (SPDS), as well as their enzyme activities (except SPDS), showed that the expression of different members of the SAMDC and SPDS gene families was affected differently in response to alteration of the cellular Put content. It was further observed that there was a strong correlation between transcript levels and the activity of the respective enzyme in the cells. Moreover, there was no feedback inhibition of the expression of the native ODC or the ADC genes or their enzyme activities by increased Put in the cells.
The organization, regulation and phylogeny of uptake hydrogenase genes in Frankia
Authors: Leul Melakeselam , Normand Philippe , Sellstedt Anita
Published: February 2007

Frankia alni ACN14a, Frankia sp. CcI3 and Frankia sp. EAN1pec, which have different host specificity and geographical distribution, have two uptake hydrogenase syntons in their genome: hydrogenase synton#1 and hydrogenase synton#2. The organization of hydrogenase genes on these syntons also varies. Phylogenetic analysis of the structural genes of these syntons showed that they were significantly divergent and that hydrogenase synton#1 subunits of these Frankia strains were probably ancestral among the actinobacteria. Hydrogenase gene duplication might have occurred long before emergence of the three Frankia lineages. The structural subunits of hydrogenase HupS2 and HupL2 (synton#2) of F. alni ACN14a and Frankia sp. CcI3, which belong to phylogenetic Frankia cluster 1, were grouped closely together but away from Frankia sp. EAN1pec, which belongs to Frankia cluster 3. Phylogenetic analysis showed the occurrence of lateral transfer of hupL2 in Frankia sp. EAN1pec to or from Geobacter sulfurreducens. The transcript levels of hupS1 and hupL1 relative to hupS2 and hupL2 were higher in F. alni ACN14a grown under free‐living conditions. Under symbiotic conditions, transcript levels of hupS2 and hupL2 were higher than those of hupS1 and hupL1. Hydrogenase subunits of synton#1 are more expressed under free‐living conditions, whereas those of synton#2 are mainly involved in symbiotic interactions.
Powdery mildew infection of wheat leaves changes host solute transport and invertase activity
Authors: Sutton Peter N. , Gilbert Martin J. , Williams Lorraine E. , Hall J. L.
Published: February 2007

The effect of powdery mildew (Blumeria graminis) infection of wheat leaves on solute transport and invertase activity of the host tissue has been examined. Sugars (glucose, sucrose, maltose) and amino acids (glutamine, histidine) were taken up by leaf pieces, and radioactivity was transferred to the fungal mycelium. Infection had a marked effect on sugar uptake, particularly for glucose which was taken up into infected tissue at considerably higher rates than into uninfected tissues. In contrast, amino acid uptake rates into infected tissues were lower when compared with those into uninfected tissue. The increase in glucose uptake could be correlated with a change in sugar transporter gene expression as a wheat homologue of the monosaccharide carrier AtSTP4 was shown to increase in infected tissue. Efflux analysis showed a higher leakage of preloaded glucose from infected leaves in comparison with uninfected tissue and transfer to the mycelium was greater for glucose than for the other solutes measured. All types of invertase, measured enzymatically, showed an increase in infected tissue, with the highest proportional increase observed for cell‐wall invertase. A partial‐length complementary DNA, TaINV2, was isolated for a putative cell‐wall invertase; expression studies indicated that levels for this or related sequences increased substantially 3 days after infection.
Modulation of Frankia alni ACN14a oxidative stress response: activity, expression and phylogeny of catalases
Authors: Santos Catarina L. , Vieira João , Sellstedt Anita , Normand Philippe , Moradas‐Ferreira Pedro , Tavares Fernando
Published: February 2007

The finding that an oxidative burst was a general phenomenon in the response of hosts challenged by various symbiotic or pathogenic microbes has stimulated increasing interest in investigating the enzymology of antioxidant protection in bacteria. The question of whether the antioxidant mechanisms have been a decisive evolutionary driving force for the nitrogen‐fixing microsymbiont Frankia spp. is still open. In this study, Frankia alni strain ACN14a, which is a mid‐range infective strain, was used as a model to explore the basal oxidative stress response in terms of enzymatic activity, relative expression and phylogeny. Non‐denaturing polyacrylamide gels stained for catalatic activity revealed the presence of two monofunctional catalases KatA and KatB (EC number 1.11.1.6), which activity was shown to increase when the cells were challenged with the oxidants H2O2 and methyl viologen. Real‐time RT‐PCR targeting the two genes showed a consistent increase in the number of transcripts when the RNA was extracted from oxidative stress‐induced cells. Comparison between the expression and the activity data suggests that posttranscriptional mechanisms might be involved in the regulation of catalases in F. alni. Furthermore, upstream of katA, a fur gene coding for a ferric uptake regulator was found, forming a gene pair that functionally resembles the conserved actinobacterial synton fur–katG, which contains a gene coding for a catalase–peroxidase. Phylogenetic analysis of the F. alni fur–katA synton suggests that this genomic organization was the result of genome reshuffling events.