Early mathematical learning: Number processing skills and executive function at 5 and 8 years of age

This research investigated differences and associations in performance in number processing and executive function for children attending primary school in a large Australian metropolitan city. In a cross-sectional study, performance of 25 children in the first full-time year of school, (Prep; mean age = 5.5 years) and 21 children in Year 3 (mean age = 8.5 years) completed three number processing tasks and three executive function tasks. Year 3 children consistently outperformed the Prep year children on measures of accuracy and reaction time, on the tasks of number comparison, calculation, shifting, and inhibition but not on number line estimation. The components of executive function (shifting, inhibition, and working memory) showed different patterns of correlation to performance on number processing tasks across the early years of school. Findings could be used to enhance teachers’ understanding about the role of the cognitive processes employed by children in numeracy learning, and so inform teachers’ classroom practices.

Association of sporadic chondrocalcinosis with a -4-basepair G-to-A transition in the 5′-untranslated region of ANKH that promotes enhanced expression of ANKH protein and excess generation of extracellular inorganic pyrophosphate

Objective Certain mutations in ANKH, which encodes a multiple-pass transmembrane protein that regulates inorganic pyrophosphate (PPi) transport, are linked to autosomal-dominant familial chondrocalcinosis. This study investigated the potential for ANKH sequence variants to promote sporadic chondrocalcinosis. Methods ANKH variants identified by genomic sequencing were screened for association with chondrocalcinosis in 128 patients with severe sporadic chondrocalcinosis or pseudogout and in ethnically matched healthy controls. The effects of specific variants on expression of common markers were evaluated by in vitro transcription/translation. The function of these variants was studied in transfected human immortalized CH-8 articular chondrocytes. Results Sporadic chondrocalcinosis was associated with a G-to-A transition in the ANKH 5′-untranslated region (5′-UTR) at 4 bp upstream of the start codon (in homozygotes of the minor allele, genotype relative risk 6.0, P = 0.0006; overall genotype association P = 0.02). This -4-bp transition, as well as 2 mutations previously linked with familial and sporadic chondrocalcinosis (+14 bp C-to-T and C-terminal GAG deletion, respectively), but not the French familial chondrocalcinosis kindred 143-bp T-to-C mutation, increased reticulocyte ANKH transcription/ANKH translation in vitro. Transfection of complementary DNA for both the wild-type ANKH and the -4-bp ANKH protein variant promoted increased extracellular PPi in CH-8 cells, but unexpectedly, these ANKH mutants had divergent effects on the expression of extracellular PPi and the chondrocyte hypertrophy marker, type X collagen. Conclusion A subset of sporadic chondrocalcinosis appears to be heritable via a -4-bp G-to-A ANKH 5′-UTR transition that up-regulates expression of ANKH and extracellular PPi in chondrocyte cells. Distinct ANKH mutations associated with heritable chondrocalcinosis may promote disease by divergent effects on extracellular PPi and chondrocyte hypertrophy, which is likely to mediate differences in the clinical phenotypes and severity of the disease.

Crystal structure of ammonium (3,5-dichlorophenoxy)acetate hemihydrate

In the structure of the title hydrated salt, NH4+·C8H5Cl2O3-·0.5H2O, where the anion derives from (3,5-di­chloro­phen­oxy)acetic acid, the ammonium cation is involved in extensive N-H...O hydrogen bonding with both carboxyl­ate and ether O-atom acceptors giving sheet structures lying parallel to (100). The water mol­ecule of solvation lies on a crystallographic twofold rotation axis and is involved in intra-sheet O-H...Ocarboxyl­ate hydrogen-bonding inter­actions. In the anion, the oxoacetate side chain assumes an antiperiplanar conformation with the defining C-O-C-C torsion angle = -171.33 (15)°.

Mimicry of 21. 5 KDa myelin basic protein peptide by a Maedi Visna virus polymerase peptide does not contribute to the pathogenesis of encephalitis in sheep

Epitope mimicry is the theory that an infectious agent such as a virus causes pathological effects via mimicry of host proteins and thus elicits a cross-reactive immune response to host tissues. Weise and Carnegie (1988) found a region of sequence similarity between the pol gene of the Maedi Visna virus (MVV), which induces demyelinating encephalitis in sheep, and myelin basic protein (MBP), which is known to induce experimental allergic encephalitis (EAE) in laboratory animals. In this study, cross-reactions between sera raised in sheep against synthetic peptides of MVV (TGKIPWILLPGR) and 21.5 kDa MBP (SGKVPWLKRPGR) were demonstrated using enzyme-linked immunosorbant assay (ELISA) and thin layer chromatography (TLC) immunoprobing. The antibody responses of MVV-infected sheep were investigated using ELISA against the peptides, and MBP protein, immunoprobing of the peptides on TPC plates and Western blotting against MBP. Slight significant reactions to the 21.5 kDa MBP peptide (P < 0.001) and to a lesser extent sheep MBP (P < 0.004) were detected in ELISA. The MBP peptide evoked stronger responses from more sera than the MVV peptide on immunoprobed TLC plates. On the Western blots, eight of the 23 sheep with Visna had serum reactivity to MBP. This slight reaction to MBP in MVV-infected sheep is of interest because of the immune responses to MBP evident in multiple sclerosis and EAE, but its relevance in Visna is limited since no correlation with disease severity was observed. The cell-mediated immune responses of MVV-infected sheep against similar peptides was assessed. The peptides did not stimulate proliferation of peripheral blood lymphocytes of MVV-infected sheep. Since the MVV peptide was not recognised by antibodies or T lymphocytes from MVV-infected and encephalic sheep, it was concluded that epitope mimicry of this 21.5 kDa MBP peptide by the similar MVV pol peptide was not contributing to the immunopathogenesis of Visna. The slight antibody response to MBP and the MBP peptide can be attributed to by-stander effects of the immunopathology of MVV-induced encephalitis.

Crystal structures of the potassium and rubidium salts of (3,5-dichlorophenoxy)acetic acid: Two isotypic coordination polymers

The two-dimensional coordination polymeric structures of the hydrated potassium and rubidium salts of (3,5-dichlorophenoxy)acetic acid, (3,5-D) namely, poly[mu-aqua-bis[mu3-2-(3,5-dichlorophenoxy)acetato]potassium, [K2(C8H5Cl2O3)2 (H2O)]n (I) and poly[mu-aqua-bis[mu3-2-(3,5-dichlorophenoxy)acetato]dirubidium] [Rb2(C8H5Cl2O3)2 (H2O)]n (II), respectively have been determined and are described. The two compounds are isotypic and the polymer is based on centrosymmetric dinuclear bridged complex units. The irregular six-coordination about the metal centres comprises a bridging water molecule lying on a twofold rotation axis, the phenoxy O-atom donor and and a triple bridging carboxylate O-atom of the oxoacetate side chain of the 3,5-D ligand in a bidentate chelate mode, the second carboxy O-donor, also bridging. The K-O and Rb-O bond-length ranges are 2.7238(15)--2.9459(14) and 2.832(2)--3.050(2) \%A respectively and the K...K and Rb...Rb separations in the dinuclear unit are 4.0214(7) and 4.1289(6) \%A, respectively. Within the two-dimensional layers which lie parallel to (100), the coordinated water molecule forms an O---H...O hydrogen bond to the single bridging carboxylate O atom.

Maternal pregravid body mass index and child hospital admissions in the first 5 years of life: results from an Australian birth cohort

Objectives: To examine the association of maternal pregravid body mass index (BMI) and child offspring, all-cause hospitalisations in the first 5 years of life. Methods: Prospective birth cohort study. From 2006 to 2011, 2779 pregnant women (2807 children) were enrolled in the Environments for Healthy Living: Griffith birth cohort study in South-East Queensland, Australia. Hospital delivery record and self-report baseline survey of maternal, household and demographic factors during pregnancy were linked to the Queensland Hospital Admitted Patients Data Collection from 1 November 2006 to 30 June 2012, for child admissions. Maternal pregravid BMI was classified as underweight (<18.5 kg m−2), normal weight (18.5–24.9 kg m−2), overweight (25.0–29.9 kg m−2) or obese (30 kg m−2). Main outcomes were the total number of child hospital admissions and ICD-10-AM diagnostic groupings in the first 5 years of life. Negative binomial regression models were calculated, adjusting for follow-up duration, demographic and health factors. The cohort comprised 8397.9 person years (PYs) follow-up. Results: Children of mothers who were classified as obese had an increased risk of all-cause hospital admissions in the first 5 years of life than the children of mothers with a normal BMI (adjusted rate ratio (RR) =1.48, 95% confidence interval 1.10–1.98). Conditions of the nervous system, infections, metabolic conditions, perinatal conditions, injuries and respiratory conditions were excessive, in both absolute and relative terms, for children of obese mothers, with RRs ranging from 1.3–4.0 (PYs adjusted). Children of mothers who were underweight were 1.8 times more likely to sustain an injury or poisoning than children of normal-weight mothers (PYs adjusted). Conclusion: Results suggest that if the intergenerational impact of maternal obesity (and similarly issues related to underweight) could be addressed, a significant reduction in child health care use, costs and public health burden would be likely.

Synthesis and luminescent properties of star-burst D-Pi-A compounds based on 1,3,5-triazine core and carbazole end-capped phenylene ethynylene arms

Two new star-burst compounds based on 1,3,5-triazine core and carbazole end-capped phenylene ethynylene arms (1a and 1b) were synthesized and characterized. Their photophysical properties were investigated systematically via spectroscopic and theoretical methods. Both compounds exhibit strong 1π–π⁎ transitions in the UV region and intense 1π–π⁎/intramolecular charge transfer (1ICT) absorption bands in the UV–vis region. Introducing the carbazole end-capped phenylene ethynylene arm on the 1,3,5-triazine core causes a slight bathochromic shift and enhanced molar extinction coefficient of the 1π–π⁎/1ICT transition band. Both compounds are emissive in solution at room temperature and 77 K, which exhibit pronounced positive solvatochromic effect. The emitting state could be ascribed to 1ICT state in more polar solvent, and 1π–π⁎ state in low-polarity solvent. The high emission quantum yields (Φem=0.90~1.0) of 1a and 1b (in hexane and toluene) make them potential candidates as efficient light-emitting materials. The spectroscopic studies and theoretical calculations indicate that the photophysical properties of these compounds can be tuned by the carbazole end-capped phenylene ethynylene arm, which would also be useful for rational design of photofunctional materials.

5-year Chlamydia vaccination programme could reverse disease-related koala population decline: Predictions from a mathematical model using field data

BACKGROUND Many koala populations around Australia are in serious decline, with a substantial component of this decline in some Southeast Queensland populations attributed to the impact of Chlamydia. A Chlamydia vaccine for koalas is in development and has shown promise in early trials. This study contributes to implementation preparedness by simulating vaccination strategies designed to reverse population decline and by identifying which age and sex category it would be most effective to target. METHODS We used field data to inform the development and parameterisation of an individual-based stochastic simulation model of a koala population endemic with Chlamydia. The model took into account transmission, morbidity and mortality caused by Chlamydia infections. We calibrated the model to characteristics of typical Southeast Queensland koala populations. As there is uncertainty about the effectiveness of the vaccine in real-world settings, a variety of potential vaccine efficacies, half-lives and dosing schedules were simulated. RESULTS Assuming other threats remain constant, it is expected that current population declines could be reversed in around 5-6 years if female koalas aged 1-2 years are targeted, average vaccine protective efficacy is 75%, and vaccine coverage is around 10% per year. At lower vaccine efficacies the immunological effects of boosting become important: at 45% vaccine efficacy population decline is predicted to reverse in 6 years under optimistic boosting assumptions but in 9 years under pessimistic boosting assumptions. Terminating a successful vaccination programme at 5 years would lead to a rise in Chlamydia prevalence towards pre-vaccination levels. CONCLUSION For a range of vaccine efficacy levels it is projected that population decline due to endemic Chlamydia can be reversed under realistic dosing schedules, potentially in just 5 years. However, a vaccination programme might need to continue indefinitely in order to maintain Chlamydia prevalence at a sufficiently low level for population growth to continue.

Experimental and theoretical characterization of 5,10- diminoporphodimethenes: Dearomatized porphyrinoids from palladium-catalyzed hydrazinations of 5,10-diarylporphyrins

A new dearomatized porphyrinoid, 5,10-diiminoporphodimethene (5,10-DIPD), has been prepared by palladium-catalyzed hydrazination of 5,10-dibromo-15,20-bis(3,5-di-tert-butylphenyl)porphyrin and its nickel(II) complex, by using ethyl and 4-methoxybenzyl carbazates. The oxidative dearomatization of the porphyrin ring occurs in high yield. Further oxidation with 2,3-dichloro-5,6-dicyanobenzoquinone forms the corresponding 5,10-bis(azocarboxylates), thereby restoring the porphyrin aromaticity. The UV/visible spectra of the NiII DIPDs exhibit remarkable redshifts of the lowest-energy bands to 780 nm, and differential pulse voltammetry reveals a contracted electrochemical HOMO–LUMO gap of 1.44 V. Density functional theory (DFT) was used to calculate the optimized geometries and frontier molecular orbitals of model 5,10-DIPD Ni7c and 5,10-bis(azocarboxylate) Ni8c. The conformations of the carbamate groups and the configurations of the CNZ unit were considered in conjunction with the NOESY spectra, to generate the global minimum geometry and two other structures with slightly higher energies. In the absence of solution data regarding conformations, ten possible local minimum conformations were considered for Ni8c. Partition of the porphyrin macrocycle into tri- and monopyrrole fragments in Ni7c and the inclusion of terminal conjugating functional groups generate unique frontier molecular orbital distributions and a HOMO–LUMO transition with a strong element of charge transfer from the monopyrrole ring. Time-dependent DFT calculations were performed for the three lowest-energy structures of Ni7c and Ni8c, and weighting according to their energies allowed the prediction of the electronic spectra. The calculations reproduce the lower-energy regions of the spectra and the overall forms of the spectra with high accuracy, but agreement is not as good in the Soret region below 450 nm.

Dissection of the genetics of Parkinson's disease identifies an additional association 5' of SNCA and multiple associated haplotypes at 17q21

We performed a genome-wide association study (GWAS) in 1705 Parkinson's disease (PD) UK patients and 5175 UK controls, the largest sample size so far for a PD GWAS. Replication was attempted in an additional cohort of 1039 French PD cases and 1984 controls for the 27 regions showing the strongest evidence of association (P < 10 4). We replicated published associations in the 4q22/SNCA and 17q21/MAPT chromosome regions (P < 10 10) and found evidence for an additional independent association in 4q22/SNCA.A detailed analysis of the haplotype structure at 17q21 showed that there are three separate risk groups within this region. We found weak but consistent evidence of association for common variants located in three previously published associated regions (4p15/BST1, 4p16/GAK and 1q32/PARK16). We found no support for the previously reported SNP association in 12q12/LRRK2. We also found an association of the two SNPs in 4q22/SNCA with the age of onset of the disease. © The Author 2010. Published by Oxford University Press.

Identification of IL6R and chromosome 11q13.5 as risk loci for asthma

We aimed to identify novel genetic variants affecting asthma risk, since these might provide novel insights into molecular mechanisms underlying the disease. We did a genome-wide association study (GWAS) in 2669 physician-diagnosed asthmatics and 4528 controls from Australia. Seven loci were prioritised for replication after combining our results with those from the GABRIEL consortium (n=26 475), and these were tested in an additional 25 358 independent samples from four in-silico cohorts. Quantitative multi-marker scores of genetic load were constructed on the basis of results from the GABRIEL study and tested for association with asthma in our Australian GWAS dataset. Two loci were confirmed to associate with asthma risk in the replication cohorts and reached genome-wide significance in the combined analysis of all available studies (n=57 800): rs4129267 (OR 1·09, combined p= 2·4×10-8) in the interleukin-6 receptor (IL6R) gene and rs7130588 (OR 1·09, p=1·8×10-8) on chromosome 11q13.5 near the leucine-rich repeat containing 32 gene (LRRC32, also known as GARP). The 11q13.5 locus was significantly associated with atopic status among asthmatics (OR 1·33, p=7×10-4), suggesting that it is a risk factor for allergic but not non-allergic asthma. Multi-marker association results are consistent with a highly polygenic contribution to asthma risk, including loci with weak effects that might be shared with other immune-related diseases, such as NDFIP1, HLA-B, LPP, and BACH2. The IL6R association further supports the hypothesis that cytokine signalling dysregulation affects asthma risk, and raises the possibility that an IL6R antagonist (tocilizumab) may be effective to treat the disease, perhaps in a genotype-dependent manner. Results for the 11q13.5 locus suggest that it directly increases the risk of allergic sensitisation which, in turn, increases the risk of subsequent development of asthma. Larger or more functionally focused studies are needed to characterise the many loci with modest effects that remain to be identified for asthma. National Health and Medical Research Council of Australia. A full list of funding sources is provided in the webappendix. © 2011 Elsevier Ltd.

Indium clusters on the Ge (5× 5) wetting layer of Si (111)- 7× 7

The adsorption of In on the Si(111)−Ge(5×5) surface reconstruction has been studied with scanning tunneling microscopy and ab initio calculations to investigate the possibility of using this reconstruction as a template for cluster formation. As with In adsorption on Si(111)−7×7 at low substrate temperatures and low In fluences, the In adatoms are found to preferentially adsorb on the faulted half-unit cell. However, in contrast to In adsorption on Si(111)−7×7, the In adatoms are also frequently found in the unfaulted half-unit cell at low coverages. The filling of unfaulted unit cell halves is primarily due to the formation of large clusters that span multiple substrate half-unit cells. Moreover, many of the faulted half-unit cells have a streaked appearance that indicates that surface atoms within them are mobile.

The cross-talk of LDL-cholesterol with cell migration: Insights from the Niemann Pick Type C1 mutation

Cholesterol is considered indispensible for the recruitment and functioning of integrins in focal adhesions for cell migration. However, the physiological cholesterol pools that control integrin trafficking and focal adhesion assembly remain unclear. Using Niemann Pick Type C1 (NPC) mutant cells, which accumulate Low Density lipoprotein (LDL)-derived cholesterol in late endosomes (LE), several recent studies indicate that LDL-cholesterol has multiple roles in regulating focal adhesion dynamics. Firstly, targeting of endocytosed LDL-cholesterol from LE to focal adhesions controls their formation at the leading edge of migrating cells. Other newly emerging literature suggests that this may be coupled to vesicular transport of integrins, Src kinase and metalloproteases from the LE compartment to focal adhesions. Secondly, our recent work identified LDL-cholesterol as a key factor that determines the distribution and ability of several Soluble NSF Attachment Protein (SNAP) Receptor (SNARE) proteins, key players in vesicle transport, to control integrin trafficking to the cell surface and extracellular matrix (ECM) secretion. Collectively, dietary, genetic and pathological changes in cholesterol metabolism may link with efficiency and speed of integrin and ECM cell surface delivery in metastatic cancer cells. This commentary will summarize how direct and indirect pathways enable LDL-cholesterol to modulate cell motility.

Nutritional rehabilitation in cystic fibrosis: A 5 year follow-up study

Previously, we reported catch-up weight gain, growth, and improved lung function in a group of malnourished cystic fibrosis (CF) children receiving aggressive nutritional supplementation for 1 year compared with a forced expiratory volume in 1 s (FEV1)-, height-, and sex-matched comparison group receiving standard therapy. To evaluate long-term effects, the clinical progress of both groups has been studied over a 5 year period. The supplemented group (n = 10) received supplements for a median of 1.35 years to achieve nutritional rehabilitation. Compared with the nonsupplemented group (n = 14), the previously supplemented group had lower mortality (2 vs. 4, N.S.) and significantly greater weight and height z scores at 4 and 5 years. The progression of pulmonary function abnormalities as measured by FEV, and forced vital capacity (FVC) slopes was greater at 3 years in the nonsupplemented group (FEV1, p < 0.05) but no significant differences in rates of deterioration of pulmonary function were seen after 5 years in the two groups of survivors. We conclude that intensive nutritional support for 1 year has both short-and long-term effects on nutrition and growth, still evident some years after the cessation of this therapeutic modality. Supplementation for periods of longer than 1 year may produce greater gains and possibly prolong the improvement in pulmonary function observed in the earlier study. © 1992 Raven Press, Ltd., New York.

General practitioner utilisation amongst urban Aboriginal and Torres Strait Islander children aged less than 5 years

Aim There are limited studies documenting the frequency and reason for attendance to primary health care services in Australian children, particularly for urban Aboriginal and Torres Strait Islander children. This study describes health service utilisation in this population in an urban setting. Methods An ongoing prospective cohort study of Aboriginal and Torres Strait Islander children aged <5 years registered with an urban Aboriginal and Torres Strait Islander primary health care centre in Brisbane, Australia. Detailed demographic, clinical, health service utilisation and risk factor data are collected by Aboriginal researchers at enrolment and monthly for a period of 12 months on each child. The incidence of health service utilisation was calculated according to the Poisson distribution. Results Between 14 February 2013 and 31 October 2014, 118 children were recruited, providing data for 535 child-months of observation. Ninety-one percent of children were Aboriginal, 4% Torres Strait Islander and 5% were both Aboriginal and Torres Strait Islander. The incidence of presentations to see a doctor for any reason was 43.9 episodes/100 child months (95%CI 38.4 – 49.9) The most common reasons for presentation were for immunisations (23%), respiratory illnesses (19%) and for Australian Government funded Indigenous child health check (16%). The primary health services used, for majority of these visits were Aboriginal and Torres Strait Islander specific medical services (61%). Conclusions Within a cultural-specific service for an urban Aboriginal and Torres Strait Islander people, there is a high frequency of childhood attendance at for primary health care services. Well-health checks and respiratory illnesses were the most common reasons. The high proportion of visits for well child services suggests a potential for opportunistic health promotion, education and early interventions across a range of child health issues.