bluuebunny/crossref_metadata_2025 huggingface dataset:
BlindCall: ultra-fast base-calling of high-throughput sequencing data by blind deconvolution
Authors: Ye Chengxi , Hsiao Chiaowen , Corrada Bravo Héctor
Published: January 2014

Motivation: Base-calling of sequencing data produced by high-throughput sequencing platforms is a fundamental process in current bioinformatics analysis. However, existing third-party probabilistic or machine-learning methods that significantly improve the accuracy of base-calls on these platforms are impractical for production use due to their computational inefficiency.

Results: We directly formulate base-calling as a blind deconvolution problem and implemented BlindCall as an efficient solver to this inverse problem. BlindCall produced base-calls at accuracy comparable to state-of-the-art probabilistic methods while processing data at rates 10 times faster in most cases. The computational complexity of BlindCall scales linearly with read length making it better suited for new long-read sequencing technologies.

Availability and Implementation: BlindCall is implemented as a set of Matlab scripts available for download at http://cbcb.umd.edu/∼hcorrada/secgen.

Contact:  hcorrada@umiacs.umd.edu
Efficient haplotype matching and storage using the positional Burrows–Wheeler transform (PBWT)
Authors: Durbin Richard
Published: January 2014

Motivation: Over the last few years, methods based on suffix arrays using the Burrows–Wheeler Transform have been widely used for DNA sequence read matching and assembly. These provide very fast search algorithms, linear in the search pattern size, on a highly compressible representation of the dataset being searched. Meanwhile, algorithmic development for genotype data has concentrated on statistical methods for phasing and imputation, based on probabilistic matching to hidden Markov model representations of the reference data, which while powerful are much less computationally efficient. Here a theory of haplotype matching using suffix array ideas is developed, which should scale too much larger datasets than those currently handled by genotype algorithms.

Results: Given M sequences with N bi-allelic variable sites, an O(NM) algorithm to derive a representation of the data based on positional prefix arrays is given, which is termed the positional Burrows–Wheeler transform (PBWT). On large datasets this compresses with run-length encoding by more than a factor of a hundred smaller than using gzip on the raw data. Using this representation a method is given to find all maximal haplotype matches within the set in O(NM) time rather than O(NM2) as expected from naive pairwise comparison, and also a fast algorithm, empirically independent of M given sufficient memory for indexes, to find maximal matches between a new sequence and the set. The discussion includes some proposals about how these approaches could be used for imputation and phasing.

Availability:  http://github.com/richarddurbin/pbwt

Contact:  richard.durbin@sanger.ac.uk
Standardizing compositional data for stock assessment
Authors: Thorson James T.
Published: January 2014

Stock assessment models frequently integrate abundance index and compositional (e.g. age, length, sex) data. Abundance indices are generally estimated using index standardization models, which provide estimates of index standard errors while accounting for: (i) differences in sampling intensity spatially or over time; (ii) non-independence of available data; and (iii) the effect of covariates. However, compositional data are not generally processed using a standardization model, so effective sample size is not routinely estimated and these three issues are unresolved. I therefore propose a computationally simple “normal approximation” method for standardizing compositional data and compare this with design-based and Dirichlet-multinomial (D-M) methods for analysing compositional data. Using simulated data from a population with multiple spatial strata, heterogeneity within strata, differences in sampling intensity, and additional overdispersion, I show that the normal-approximation method provided unbiased estimates of abundance-at-age and estimates of effective sample size that are consistent with the imprecision of these estimates. A conventional design-based method also produced unbiased age compositions estimates but no estimate of effective sample size. The D-M failed to account for known differences in sampling intensity (the proportion of catch for each fishing trip that is sampled for age) and hence provides biased estimates when sampling intensity is correlated with variation in abundance-at-age data. I end by discussing uses for “composition-standardization models” and propose that future research develop methods to impute compositional data in strata with missing data.
G-Quadruplex binding enantiomers show chiral selective interactions with human telomere
Authors: Wang Jiasi , Chen Yong , Ren Jinsong , Zhao Chuanqi , Qu Xiaogang
Published: January 2014

Chiral recognition of DNA molecules is important because DNA chiral transition and its different conformations are involved in a series of important life events. Among them, polymorphic human telomere DNA has attracted great interests in recent years because of its important roles in chromosome structural integrity. In this report, we examine the short-term effect of chiral metallo-supramolecular complex enantiomers treatment on tumor cells, and find that a zinc-finger-like alpha helical chiral metallo-supramolecular complex, [Ni2L3]4+-P enantiomer (NiP), can selectively provoke the rapid telomere uncapping, trigger DNA damage responses at telomere and degradation of G-overhang and the delocalization of telomeric protein from telomeres. Further studies indicate that NiP can induce an acute cellular apoptosis and senescence in cancer cells rather than normal cells. These results are further evidenced by the upregulation of p21 and p16 proteins. Moreover, NiP can cause translocation of hTERT from nuclear to cytoplasm through Tyr 707 phosphorylation. While its enantiomer, [Ni2L3]4+-M (NiM), has no such mentioned effects, these results clearly demonstrate the compound’s chiral selectivity in cancer cells. Our work will shed light on design of chiral anticancer drugs targeting G-quadruplex DNA, and developing telomere and telomerase modulation agents.
CpG domains downstream of TSSs promote high levels of gene expression
Authors: Krinner Simone , Heitzer Asli P. , Diermeier Sarah D. , Obermeier Ingrid , Längst Gernot , Wagner Ralf
Published: January 2014

CpG dinucleotides are known to play a crucial role in regulatory domains, affecting gene expression in their natural context. Here, we demonstrate that intragenic CpG frequency and distribution impacts transgene and genomic gene expression levels in mammalian cells. As shown for the Macrophage Inflammatory Protein 1α, de novo RNA synthesis correlates with the number of CpG dinucleotides, whereas RNA splicing, stability, nuclear export and translation are not affected by the sequence modification. Differences in chromatin accessibility in vivo and altered nucleosome positioning in vitro suggest that increased CpG levels destabilize the chromatin structure. Moreover, enriched CpG levels correlate with increased RNA polymerase II elongation rates in vivo. Interestingly, elevated CpG levels particularly at the 5′ end of the gene promote efficient transcription. We show that this is a genome-wide feature of highly expressed genes, by identifying a domain of ∼700 bp with high CpG content downstream of the transcription start site, correlating with high levels of transcription. We suggest that these 5′ CpG domains are required to distort the chromatin structure and to increase gene activity.
Film size-dependent voltage-modulated magnetism in multiferroic heterostructures
Authors: Hu J.-M. , Shu L. , Li Z. , Gao Y. , Shen Y. , Lin Y. H. , Chen L. Q. , Nan C. W.
Published: January 2014

The electric-voltage-modulated magnetism in multiferroic heterostructures, also known as the converse magnetoelectric (ME) coupling, has drawn increasing research interest recently owing to its great potential applications in future low-power, high-speed electronic and/or spintronic devices, such as magnetic memory and computer logic. In this article, based on combined theoretical analysis and experimental demonstration, we investigate the film size dependence of such converse ME coupling in multiferroic magnetic/ferroelectric heterostructures, as well as exploring the interaction between two relating coupling mechanisms that are the interfacial strain and possibly the charge effects. We also briefly discuss some issues for the next step and describe new device prototypes that can be enabled by this technology.
Description of Thalassotalea piscium gen. nov., sp. nov., isolated from flounder (Paralichthys olivaceus), reclassification of four species of the genus Thalassomonas as members of the genus Thalassotalea gen. nov. and emended description of the genus Thalassomonas
Authors: Zhang Yunhui , Tang Kaihao , Shi Xiaochong , Zhang Xiao-Hua
Published: January 2014

A Gram-staining-negative, aerobic, rod-shaped bacterium, designated strain T202T, was isolated from the gill of a cultured flounder (Paralichthys olivaceus). Based on 16S rRNA gene sequence similarity, strain T202T was a member of the family

Colwelliaceae

and shared 93.32–96.58 % similarity with type strains of all members of the most closely related genus

Thalassomonas

. Phylogenetically, the isolate shared a root with the type strains of four marine species,

Thalassomonas agariperforans

M-M1T,

Thalassomonas agarivorans

TMA1T,

Thalassomonas loyana

CBMAI 722T and

Thalassomonas ganghwensis

JC2041T. Optimal growth occurred in the presence of 2–4 % (w/v) NaCl, at pH 7.0–8.0 and at 28 °C. Ubiquinone 8 (Q-8) was the predominant respiratory quinone. The major fatty acids were C16 : 0, summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c), C16 : 1ω9c and C17 : 1ω8c. The major polar lipids were phosphatidylethanolamine and phosphatidylglycerol. The DNA G+C content of strain T202T was 37 mol%. On the basis of polyphasic analysis, especially the phylogenetic relationships and the lower DNA G+C content, strain T202T is considered to represent a novel species in a new genus, for which the name Thalassotalea piscium gen. nov., sp. nov. is proposed. The type strain of Thalassotalea piscium is T202T ( = JCM 18590T = DSM 26287T = KCTC 32144T). Because

Thalassomonas agariperforans

M-M1T,

Thalassomonas agarivorans

TMA1T,

Thalassomonas loyana

CBMAI 722T and

Thalassomonas ganghwensis

JC2041T formed a phylogenetic group together with strain T202T that was clearly separated from other known strains of

Thalassomonas

, these four species are reclassified as members of the genus Thalassotalea as Thalassotalea agariperforans comb. nov. (type strain M-M1T = KCTC 23343T = CCUG 60020T), Thalassotalea agarivorans comb. nov. (type strain TMA1T = BCRC 17492T = JCM 13379T = DSM 19706T), Thalassotalea loyana comb. nov. (type strain CBMAI 722T = LMG 22536T) and Thalassotalea ganghwensis comb. nov. (type strain JC2041T = IMSNU 14005T = KCTC 12041T = DSM 15355T). The type species of the genus Thalassotalea is Thalassotalea ganghwensis gen. nov., comb. nov. An emended description of the genus

Thalassomonas

is also proposed.
Complete genome analysis identifies Tvärminne avian virus as a candidate new species within the genus Orthoreovirus
Authors: Dandár Eszter , Huhtamo Eili , Farkas Szilvia L. , Oldal Miklós , Jakab Ferenc , Vapalahti Olli , Bányai Krisztián
Published: January 2014

Orthoreoviruses have been associated with a variety of diseases in domesticated poultry and wild-living birds. In 2002, a reovirus strain named Tvärminne avian virus (TVAV), was identified in Finland in a crow showing neurological disorders. The objective of this study was the molecular characterization of this novel reovirus strain. Genome sequencing was performed by combining semiconductor sequencing and traditional capillary sequencing. Sequence and phylogenetic analyses showed that TVAV shares low nucleotide sequence identity with other reoviruses (range for each gene, 31–72 %) including strains belonging to the species Avian orthoreovirus. The most closely related reovirus strain was an isolate identified in Steller sea lion. Our data indicate that TVAV is a divergent reovirus of avian origin that may be the first representative of a distinct virus species within the genus Orthoreovirus.
Roles of conserved residues within the pre-NH2-terminal domain of herpes simplex virus 1 DNA polymerase in replication and latency in mice
Authors: Terrell Shariya L. , Pesola Jean M. , Coen Donald M.
Published: January 2014

The catalytic subunit of the herpes simplex virus 1 DNA polymerase (HSV-1 Pol) is essential for viral DNA synthesis and production of infectious virus in cell culture. While mutations that affect 5′–3′ polymerase activity have been evaluated in animal models of HSV-1 infection, mutations that affect other functions of HSV-1 Pol have not. In a previous report, we utilized bacterial artificial chromosome technology to generate defined HSV-1 pol mutants with lesions in the previously uncharacterized pre-NH2-terminal domain. We found that the extreme N-terminal 42 residues (deletion mutant polΔN43) were dispensable for replication in cell culture, while residues 44–49 (alanine-substitution mutant polA6) were required for efficient viral DNA synthesis and production of infectious virus. In this study, we sought to address the importance of these conserved elements in viral replication in a mouse corneal infection model. Mutant virus polΔN43 exhibited no meaningful defect in acute or latent infection despite strong conservation of residues 1–42 with HSV-2 Pol. The polA6 mutation caused a modest defect in replication at the site of inoculation, and was severely impaired for ganglionic replication, even at high inocula that permitted efficient corneal replication. Additionally, the polA6 mutation resulted in reduced latency establishment and subsequent reactivation. Moreover, we found that the polA6 replication defect in cultured cells was exacerbated in resting cells as compared to dividing cells. These results reveal an important role for the conserved motif at residues 44–49 of HSV-1 Pol for ganglionic viral replication.
Human paternal and maternal demographic histories: insights from high-resolution Y chromosome and mtDNA sequences
Authors: Lippold Sebastian , Xu Hongyang , Ko Albert , Li Mingkun , Renaud Gabriel , Butthof Anne , Schröder Roland , Stoneking Mark
Published: January 2014

To investigate in detail the paternal and maternal demographic histories of humans, we obtained ∼500 kb of non-recombining Y chromosome (NRY) sequences and complete mtDNA genome sequences from 623 males from 51 populations in the CEPH Human Genome Diversity Panel (HGDP). Our results: confirm the controversial assertion that genetic differences between human populations on a global scale are bigger for the NRY than for mtDNA; suggest very small ancestral effective population sizes (<100) for the out-of-Africa migration as well as for many human populations; and indicate that the ratio of female effective population size to male effective population size (Nf/Nm) has been greater than one throughout the history of modern humans, and has recently increased due to faster growth in Nf. However, we also find substantial differences in patterns of mtDNA vs. NRY variation in different regional groups; thus, global patterns of variation are not necessarily representative of specific geographic regions.
A Hydraulic Model Is Compatible with Rapid Changes in Leaf Elongation under Fluctuating Evaporative Demand and Soil Water Status
Authors: Caldeira Cecilio F. , Bosio Mickael , Parent Boris , Jeanguenin Linda , Chaumont François , Tardieu François
Published: January 2014

Plants are constantly facing rapid changes in evaporative demand and soil water content, which affect their water status and growth. In apparent contradiction to a hydraulic hypothesis, leaf elongation rate (LER) declined in the morning and recovered upon soil rehydration considerably quicker than transpiration rate and leaf water potential (typical half-times of 30 min versus 1–2 h). The morning decline of LER began at very low light and transpiration and closely followed the stomatal opening of leaves receiving direct light, which represent a small fraction of leaf area. A simulation model in maize (Zea mays) suggests that these findings are still compatible with a hydraulic hypothesis. The small water flux linked to stomatal aperture would be sufficient to decrease water potentials of the xylem and growing tissues, thereby causing a rapid decline of simulated LER, while the simulated water potential of mature tissues declines more slowly due to a high hydraulic capacitance. The model also captured growth patterns in the evening or upon soil rehydration. Changes in plant hydraulic conductance partly counteracted those of transpiration. Root hydraulic conductivity increased continuously in the morning, consistent with the transcript abundance of Zea maize Plasma Membrane Intrinsic Protein aquaporins. Transgenic lines underproducing abscisic acid, with lower hydraulic conductivity and higher stomatal conductance, had a LER declining more rapidly than wild-type plants. Whole-genome transcriptome and phosphoproteome analyses suggested that the hydraulic processes proposed here might be associated with other rapidly occurring mechanisms. Overall, the mechanisms and model presented here may be an essential component of drought tolerance in naturally fluctuating evaporative demand and soil moisture.
Reversible basal ganglia lesions in neuropsychiatric lupus: a report of three pediatric cases
Authors: Sato Satoshi , Nakajima Junya , Shimura Masaru , Kawashima Hisashi , Yoshio Taku , Hara Yuko
Published: January 2014

Aim

Central nervous system involvement represents a serious and common complication of systemiclupus erythematosus (SLE). We describe the characteristics of patients with neuropsychiatric (NP) SLE complicated with reversible basal ganglia lesions.

Methods

We describe the cases of three NPSLE patients.

Results

They presented with NP manifestations such as headache, cognitive dysfunction, tremors, seizures, and mood disorder. The levels of autoantibodies to NMDA (N‐methyl‐d‐aspartate) receptor antibodies and antiribosomal‐P antibodies were elevated, indicating the presence of an acute phase. Marked elevation of interleukin‐6 in cerebrospinal fluid was noted when these patients showed NP symptoms. Moreover, the patients presented with high‐intensity lesions in the basal ganglia on T2‐weighted images, fluid‐attenuated inversion recovery (FLAIR) images, diffusion‐weighted images (DWI) and apparent diffusion coefficient (ADC) maps. Following immunosuppressive treatment, almost complete improvement of the lesions was noted.

Conclusion

The reported cases indicate that reversible vasculopathies represent vasogenic edema localized in basal ganglia lesions and that activation of the autoimmune system and inflammation could lead to NP manifestations in SLE.
The impact of thyroid autoimmunity on arterial stiffness in postmenopausal patients with fibromyalgia
Authors: Cho Kyoung Im , Lee Ji Hyun
Published: January 2014

Objective

The exact mechanism of arterial stiffness in fibromyalgia (FM) remains unclear. The present study aimed to evaluate the association between thyroid function and markers of arterial function in postmenopausal FM patients.

Methods

This study included 163 postmenopausal FM patients without any known cardiovascular diseases and within a normal reference range of thyroid‐stimulating hormone (TSH) level. Clinical parameters including the Fibromyalgia Impact Questionnaire (FIQ), the pain visual analogical scale (VAS) and tender point counts were measured. Vascular function was assessed by brachial‐ankle pulse wave velocity (baPWV) and flow‐mediated dilation (FMD). We evaluated the associations between arterial markers and serum TSH, free thyroxin, as well as serum thyroidperoxidase autoantibody (TPO Ab).

Results

Patients with a high baPWV (≥ 1490 cm/s) showed more positive TPO Ab (65% vs. 10%, P = 0.006) than those with a normal baPWV. Additionally, the baPWV values of patients with positive TPO Ab were significantly different from those with negative TPO Ab. Age, FIQ and TPO Ab were significantly correlated with baPWV and FMD (all P < 0.05). Multiple linear regression analysis revealed that the only significant predictors of baPWV were age, FIQ and the presence of TPO Ab after adjustment for traditional risk factors. A significant association was also found between FMD and positive TPO Ab.

Conclusion

Age, functional status and presence of TPO Ab were significantly associated with increased arterial stiffness in postmenopausal FM patients. Given the combined thyroid autoimmunity in FM patients, a re‐evaluation of the effects on the vasculature may be necessary.
Chronic glucocorticoid treatment enhances lipogenic activity in visceral adipocytes of male Wistar rats
Authors: Chimin P. , Farias T. da S. M. , Torres‐Leal F. L. , Bolsoni‐Lopes A. , Campaña A. B. , Andreotti S. , Lima F. B.
Published: January 2014

Aim

Glucocorticoid (GC) in excess promotes the redistribution of adipose tissue from peripheral to central sites of the body. In this study, we characterized an experimental condition of prolonged GC excess and investigated its effect on the lipogenic metabolism in white adipose tissue.

Methods

Twenty male Wistar rats were divided into control (CON) and dexamethasone‐treated (DEX) groups. DEX group received dexamethasone (0.25 mg kg−1 day−1) during 4 weeks, while CON group received saline. Animals were killed and subcutaneous (SC), retroperitoneal (RP) and mesenteric (MS) fat pads were excised, weighed and processed for adipocyte isolation, morphometric cell analysis and incorporation of glucose into lipids.

Results

The treatment effectively blocked hypothalamic–pituitary–adrenal axis, as verified by a 58% decrease in plasma corticosterone levels and 19% atrophy in adrenal glands in DEX group. Animals from DEX group presented insulin resistance, glucose intolerance, dyslipidaemia and increased insulin and leptin plasma levels and hypertrophied adipocytes. They showed increased lipogenesis in RP and MS depots, with increased incorporation of glucose into fatty acids of triacylglycerol. Increased activity of lipogenic enzymes ATP‐citrate lyase, fatty acid synthase, glucose‐6‐phosphate dehydrogenase and malic was only seen in the MS depot in DEX group, while gene expression of these enzymes was enhanced in SC and MS fat depots.

Conclusion

The adaptations promoted by GC treatment in adipose metabolism seemed to be mainly due to the increased activity of enzymes that supply the NADPH required for lipogenesis than to the increase in enzymes that more directly deal with fatty acid synthesis itself.
Policy intermediaries and the reform of e‐Education inSouthAfrica
Authors: Vandeyar Thirusellvan
Published: January 2014

Utilising a case study approach and backward mapping principles to policy implementation, this study set out to explore how well district and province's e‐learning officials are equipped for the task of implementing the national e‐Education policy. Qualitative methods were employed to capture data through interviews and document analysis. Data were analysed using grounded theory methods. Analyses of e‐learning official's constructions about information and communication technology implementation in schools yielded patterns in their understandings of policy implementation. Findings were fourfold. First, district and provincial e‐learning leaders superficially understood the e‐Education policy, missing policy intent of their role as policy intermediaries. Second, they perceived their role mainly as policy conduits focusing on the dissemination of the policy to schools. Third, the compartmentalisation of directorates performing the same function lacked communication, interaction and coherence. Fourth, district's capacity and lack of competence impacted negatively on their ability to implement policy and support schools. This study suggests that for intermediaries to be effective implementers of policy, they need to become teachers of policy. In order to achieve this, it becomes necessary and crucial for them to participate in the process of policy formulation, appropriation, interpretation and the learning of policy.

However much policy makers may have wished the districts to be able to perform what official policy aspired to, the reality is otherwise.
Plasma–photocatalytic degradation of dyeing wastewater: comparison of titanium oxide, zinc oxide, and graphene oxide
Authors: Jang Doo Il , Hyun Young Jin , Park Hoeman , Mok Young Sun
Published: January 2014

Non‐thermal plasma combined with photocatalysis is a viable technique for the degradation of organic impurities in wastewater. In this work, a specially devised dielectric barrier discharge plasma reactor system coupled with photocatalysis was applied to the degradation of CI Acid Red 4 which is commonly used as a textile dye. Dye degradation in the combined system was evaluated with three different photocatalysts: titanium oxide, zinc oxide, and graphene oxide. The photocatalysts were characterised by X‐ray diffraction, particle size analysis, and Brunauer–Emmett–Teller specific surface area. It was found that the combination of photocatalysis with plasma substantially improved dye degradation by comparison with plasma alone. To identify which photocatalyst exhibited the best performance, the influence of photocatalysis alone on dye degradation was separately determined using an ultraviolet lamp, which showed that graphene oxide, which has a broad band gap, degraded the dye most effectively.
Optimising by response surface methodology the dyeing of polyester with a liposome‐encapsulated disperse dye
Authors: Sadr Dadras Farahnaz , Gharanjig Kamaladin , Raissi Sadigh
Published: January 2014

Optimisation of conditions for dyeing polyester with liposome‐encapsulated CI Disperse Red 50 was performed using response surface methodology. The effects of temperature, time, and lecithin:dye ratio on the colour strength of dyed fabrics were investigated by a central composite design. The coefficient of determination, the probability value in analysis of variance, and the normality plot of residuals demonstrated sufficient significance of the proposed fitness function. It was found that the temperature and time of the dyeing cycle were effective factors in the dyeing of polyester fabrics with encapsulated dye. It was also established that the colour yield of dyed fabrics was above 25 in the case of a dyeing time of >80 min, a lecithin:dye ratio of ≤2, and a temperature of ca. 128 °C. Comparison of colour strengths produced by liposome‐encapsulated dye and commercial dye revealed that there was approximately the same build‐up on polyester. Dyeings from encapsulated CI Disperse Red 50 exhibited very similar fastness to dyeings from conventional CI Disperse Red 50.
Sequence‐specific procedural learning deficits in children with specific language impairment
Authors: Hsu Hsinjen Julie , Bishop Dorothy V.M.
Published: January 2014

This study tested the procedural deficit hypothesis of specific language impairment (SLI) by comparing children's performance in two motor procedural learning tasks and an implicit verbal sequence learning task. Participants were 7‐ to 11‐year‐old children with SLI (n = 48), typically developing age‐matched children (n = 20) and younger typically developing children matched for receptive grammar (n = 28). In a serial reaction time task, the children with SLI performed at the same level as the grammar‐matched children, but poorer than age‐matched controls in learning motor sequences. When tested with a motor procedural learning task that did not involve learning sequential relationships between discrete elements (i.e. pursuit rotor), the children with SLI performed comparably with age‐matched children and better than younger grammar‐matched controls. In addition, poor implicit learning of word sequences in a verbal memory task (the Hebb effect) was found in the children with SLI. Together, these findings suggest that SLI might be characterized by deficits in learning sequence‐specific information, rather than generally weak procedural learning.
Shared understanding and idiosyncratic expression in early vocabularies
Authors: Mayor Julien , Plunkett Kim
Published: January 2014

To what extent do toddlers have shared vocabularies? We examined CDI data collected from 14,607 infants and toddlers in five countries and measured the amount of variability between individual lexicons during development for both comprehension and production. Early lexicons are highly overlapping. However, beyond 100 words, toddlers share more words with other toddlers in comprehension than in production, even when matched for lexicon sizes. This finding points to a structural difference in early comprehension and production: Toddlers are generalists in comprehension but develop a unique, expressive voice. Variability in production decreases after two years of age, suggesting convergence to a common expressive core vocabulary. We discuss potential exogenous and endogenous contributions to the inverted U‐shaped development observed in young children's expressive lexical variability.
Moderator effects of working memory on the stability of ADHD symptoms by dopamine receptor gene polymorphisms during development
Authors: Trampush Joey W. , Jacobs Michelle M. , Hurd Yasmin L. , Newcorn Jeffrey H. , Halperin Jeffrey M.
Published: January 2014

We tested the hypothesis that dopamine D1 and D2 receptor gene (DRD1 and DRD2, respectively) polymorphisms and the development of working memory skills can interact to influence symptom change over 10 years in children with attention‐deficit/hyperactivity disorder (ADHD). Specifically, we examined whether improvements in working memory maintenance and manipulation from childhood to early adulthood predicted the reduction of ADHD symptoms as a function of allelic variation in DRD1 and DRD2. Participants were 76 7–11‐year‐old children with ADHD who were genotyped and prospectively followed for almost 10 years. ADHD symptoms were rated using the Attention Problems scale on the Child Behavior Checklist, and verbal working memory maintenance and manipulation, measured by Digit Span forward and backward, respectively, were assessed at baseline and follow‐up. After correction for multiple testing, improvements in working memory manipulation, not maintenance, predicted reduction of symptomatology over development and was moderated by major allele homozygosity in two DRD1 polymorphisms (rs4532 and rs265978) previously linked with variation in D1 receptor expression. Depending on genetic background, developmental factors including age‐dependent variation in DRD1 penetrance may facilitate the link between improvements in higher‐order working memory and the remission of symptoms in individuals with childhood‐diagnosed ADHD. Furthermore, the current findings suggest that DRD1 might contribute minimally to the emergence of symptoms and cognitive difficulties associated with ADHD in childhood, but may act as a modifier gene of these clinical features and outcome during later development for those with ADHD.
Arithmetic facts storage deficit: the hypersensitivity‐to‐interference in memory hypothesis
Authors: De Visscher Alice , Noël Marie‐Pascale
Published: January 2014

Dyscalculia, or mathematics learning disorders, is currently known to be heterogeneous (Wilson & Dehaene, ). While various profiles of dyscalculia coexist, a general and persistent hallmark of this math learning disability is the difficulty in memorizing arithmetic facts (Geary, Hoard & Hamson, ; Jordan & Montani, ; Slade & Russel, ). Arithmetic facts are simple arithmetic problems that are solved by direct retrieval from memory. Recently, De Visscher and Noël () showed hypersensitivity‐to‐interference in memory in an adult suffering from a specific deficit of arithmetic facts storage. According to the authors, arithmetic facts share many features. The overlapping of these features between arithmetic facts may provoke interference. Consequently, learners who are hypersensitive‐to‐interference could have considerable difficulties in storing arithmetic facts. The present study aims at testing this new hypothesis on fourth‐grade children who are learning multiplication tables. Among 101 children that were assessed, 23 low arithmetic facts learners were selected because of their low score in arithmetic facts fluency (controlling for processing speed). Twenty‐three control children were selected, matched for classroom, gender, and age. In addition to a subtest of global reasoning, these participants were given a multiplication production task and a memorization task of low‐ and high‐interference associations. The results show that children with low arithmetic fluencies experience hypersensitivity‐to‐interference in memory compared with children with typical arithmetic fluencies.
Breastfeeding and trajectories of children's cognitive development
Authors: Huang Jin , Peters Kristen E. , Vaughn Michael G. , Witko Christopher
Published: January 2014

The aim of this study was to examine the association of breastfeeding practices with the growth trajectories of children's cognitive development. We used data from the Child Development Supplement (CDS) of the Panel Study of Income Dynamics (PSID) with variables on presence and duration of breastfeeding and standardized test scores obtained during three different panel waves (N = 2681). After adjusting for covariates we found that breastfed children had higher test scores but that breastfed and non‐breastfed children had similar growth trajectories in test scores over time. The results indicate that breastfeeding has an important association with test scores, and that subsequent schooling and other experiences during adolescence do not eliminate the breastfeeding gap that appears in very early childhood.
Why do spatial abilities predict mathematical performance?
Authors: Tosto Maria Grazia , Hanscombe Ken B. , Haworth Claire M.A. , Davis Oliver S.P. , Petrill Stephen A. , Dale Philip S. , Malykh Sergey , Plomin Robert , Kovas Yulia
Published: January 2014

Spatial ability predicts performance in mathematics and eventual expertise in science, technology and engineering. Spatial skills have also been shown to rely on neuronal networks partially shared with mathematics. Understanding the nature of this association can inform educational practices and intervention for mathematical underperformance. Using data on two aspects of spatial ability and three domains of mathematical ability from 4174 pairs of 12‐year‐old twins, we examined the relative genetic and environmental contributions to variation in spatial ability and to its relationship with different aspects of mathematics. Environmental effects explained most of the variation in spatial ability (~70%) and in mathematical ability (~60%) at this age, and the effects were the same for boys and girls. Genetic factors explained about 60% of the observed relationship between spatial ability and mathematics, with a substantial portion of the relationship explained by common environmental influences (26% and 14% by shared and non‐shared environments respectively). These findings call for further research aimed at identifying specific environmental mediators of the spatial–mathematics relationship.

Research highlights

About a third of the variation in spatial ability at age 12 is explained by genetic factors; a little less than half of the variation in mathematics at this age is genetic.

We find no sex differences in the genetic and environmental influences (either in magnitude or type) on mathematical and spatial variation at age 12.

The observed overlap between spatial ability and mathematics is substantial (r > .40). Approximately 60% of this overlap is explained by common genetic effects, with 40% of the overlap due to environmental experience.
Work and Health of Parents of Adult Children with Serious Mental Illness
Authors: Song Jieun , Mailick Marsha R. , Greenberg Jan S.
Published: January 2014

This study examined the effects of work schedule flexibility and the spillover of work stress to family life on the health of parents of adult children with serious mental illness (SMI). The authors compared 100 parents of adult children with SMI to 500 parents with nondisabled adult children using data from the Wisconsin Longitudinal Study. The detrimental impact on health of a lack of work flexibility and of higher levels of negative work‐to‐family spillover was more pronounced among parents of adult children with SMI than parents with nondisabled adult children. The results have significant implications for developing interventions to help midlife families of persons with SMI cope with work‐related stress and for policies that provide for greater work schedule flexibility.
Disability in U.S. Households, 2000–2010: Findings from the National Health Interview Survey
Authors: Altman Barbara M. , Blackwell Debra L.
Published: January 2014

Understanding the demographic structure of households containing members with disabilities is of key importance in policy planning for populations with disabilities at state and national levels. Yet most, but not all, previous family‐level studies of disability have excluded persons living alone or with unrelated persons (e.g., a housemate or an unmarried partner) because they are not considered families. To address this gap, the authors utilize National Health Interview Survey data to produce household‐level estimates of disability using a detailed household type variable that includes households omitted from previous reports. Findings indicate that one‐person households made up 24.7% of all households with an adult age 18 to 64 with a disability, and 42.9% of all households with an adult age 65 or older with a disability. Including nonfamily households provides a clearer picture of the association between living arrangements and disability in the United States.
Network Supports and Resiliency among U.S. Military Spouses with Children with Special Health Care Needs
Authors: Farrell Anne F. , Bowen Gary L. , Swick Danielle C.
Published: January 2014

Understanding how military families who have children with special health care needs (CSHCN) successfully cope in the context of exceptional demands of the military lifestyle can inform scholarship, policy, and practice to the benefit of families. Using data from 775 female civilian parents (mothers serving as Key Spouses) married to active duty Air Force members, this study examined differences on dimensions of network support and spouse resiliency between mothers who do and do not have CSHCN, as well as the relative contribution of formal and informal network support to variation in self-reports of resiliency among mothers with CSHCN. Mothers with CSHCN experience significantly less formal and informal network support than their counterparts. Despite this, they reported equivalent overall resiliency, with lower perceived resiliency on only one of four resiliency outcomes. More formal and informal network support was generally associated with higher resilience. Implications for policy, practice, and research are discussed.
A Comparison of Physical Health Outcomes for Caregiving Parents and Caregiving Adult Children
Authors: Zehner Ourada Verna E. , Walker Alexis J.
Published: January 2014

Using data from the National Survey of Midlife Development in the United States and using the stress process model, this study compared caregiving parents and caregiving adult children with regard to health outcomes. The study sample consisted of 74 caregiving parents and 219 caregiving adult children. Predictors included type of family relationship, provision of activities of daily living, duration of caregiving, and family demands. Social support did not mediate the relations between significant predictor variables and health outcomes. The type of family relationship was associated with health outcomes with caregiving parents demonstrating poorer self‐perceived health and more chronic conditions than caregiving adult children. Perceived family demands were associated with increased number of chronic conditions for caregiving adult children and caregiving parents. Unlike previous studies that measured objective family demands, perceived family demands was found to have a strong association with the number of chronic health conditions for both groups of caregivers.
Parent Stress and Perceptions of Language Development: Comparing Down Syndrome and Other Developmental Disabilities
Authors: Smith Ashlyn L. , Romski MaryAnn , Sevcik Rose A. , Adamson Lauren B. , Barker R. Michael
Published: January 2014

This study extended research on the Down syndrome advantage by examining differences in parent stress and parent perceptions of language development between 29 parents of young children with Down syndrome and 82 parents of children with other developmental disabilities. Parents of children with Down syndrome reported lower levels of total stress, child‐related stress, and stress surrounding the parent–child interaction. Parents of children in both groups reported that they felt successful in their ability to affect their children's communication development but did differ on perceptions of difficulty such that parents of children with Down syndrome perceived their children's communication difficulties as less severe despite the children exhibiting similar language skills. Finally, after accounting for potential explanatory confounding variables, child diagnosis remained a significant predictor of parent stress and perceptions of language development. Results highlight the importance of considering etiology when assisting families raising a child with a disability.
Trajectories of Stress among Parents of Children with Disabilities: A Dyadic Analysis
Authors: Woodman Ashley C.
Published: January 2014

Parents of children with developmental disabilities (DD) face greater caregiving demands than other parents, which may lead to heightened levels of stress. Characteristics of the child with DD as well as family resources may explain the extensive variability observed in parental adjustment. This study examined trajectories of parenting stress among 108 mother–father dyads parenting a child with DD, from early childhood (age 3) through adolescence (age 15). Using multilevel dyadic analyses, stress was found to increase from early to middle childhood then subsequently decrease through adolescence. Child‐related stressors (behavior problems, adaptive behavior) and family resources (social support, positive family climate) in early childhood predicted initial levels and change in stress. Mother–father differences and recommendations for intervention are discussed.
The Impact of Work on the Mental Health of Parents of Children with Disabilities
Authors: Morris Lisa A.
Published: January 2014

There is a growing literature examining the impact of work and family responsibilities on the psychological well‐being of parents of children with disabilities and other special needs. A number of studies using small, nonprobability samples of mothers find that work provides a respite from the stressful effects of caregiving. Using data from the National Survey of American Families, this study found higher mental health among working mothers of older children with disabilities compared to their nonworking counterparts and mothers of typically developing children, a result consistent with caregiver‐specific positive spillover. No significant differences in mental health were found among working and nonworking mothers of younger children with disabilities or among fathers. Results also indicate that caregiver mothers who are experiencing high levels of parent‐role stress benefit more from work, and that the beneficial effects from work persist until rather high levels of work (50 or more hours per week).
The Political Arithmetic of Disability and the American Family: A Demographic Perspective
Authors: Fujiura Glenn T.
Published: January 2014

Demographic summaries of family households are used to draw a portrait of disability in the family. The vast majority of persons with disabilities live in a family setting, and families with a disabled member represent a significant share of all families in the population. The observed prevalence of disability within a family ranged from 22 to 37 per 100. No prototypical family type emerges in the data; household structure was variable and interacted in a complex fashion with key demographics. Economic hardship is exacerbated among families with disabilities and especially among racial or ethnic minority households, families headed by a single parent, and households that had multiple members with a disability. Related statistics on caregiving among family members indicates that the need for support from other family members is considerable. The implications for policy of selected demographic features of family households are discussed.
Self‐Determination: A Family Affair
Authors: Wehmeyer Michael L.
Published: January 2014

Due to the advocacy of families during the 20th century, children and youth with disabilities gained access to a free, appropriate education. Although people with disabilities have made significant strides in the past quarter century, in the United States and across the world, people with significant disabilities continue to experience disproportionate levels of unemployment, have few options other than to live with their families, and experience a diminished quality of life. To address this, the educational system has focused on supports and services to ensure that young people with disabilities transition from school to adulthood more successfully. Within these efforts, the promotion of self‐determination for secondary students with disabilities has become best practice, and there exist evidence‐based methods, materials, and strategies to achieve this outcome. This article discusses the importance of self‐determination for youth with disabilities to achieve successful lives and the important role that families play in that process.
Family Life Goes On: Disability in Contemporary Families
Authors: Farrell Anne F. , Krahn Gloria L.
Published: January 2014

Disability is part of life for most contemporary families, but to date the literature on disability in families is fragmented and narrow. This editorial commentary introduces the content and findings of peer‐reviewed articles appearing in a special issue of Family Relations. The editors outline unanswered but core research questions and preview the themes present in the issue: families with disabilities are diverse; economic hardship disproportionately characterizes their lives; family life with disabilities is a journey that includes stress and resilience, with support contributing significantly to the latter; and that work benefits and taxes family life. Articles extrapolate beyond findings to explore implications for family policy and practice. The editors assert that developing understanding of how disability influences families requires a more diverse and rigorous research portfolio. They further cite the need to embed disability as a variable in a range of family studies and advocate more outlets for publication.