bluuebunny/crossref_metadata_2025_split huggingface dataset:
Methylenetetrahydrofolate reductase deficiency and low dietary folate increase embryonic delay and placental abnormalities in mice
Authors: Pickell Laura , Li Deqiang , Brown Katharine , Mikael Leonie G. , Wang Xiao‐Ling , Wu Qing , Luo Li , Jerome‐Majewska Loydie , Rozen Rima 
Published: February 2009

AbstractBACKGROUND:Despite extensive research on mild methylenetetrahydrofolate reductase (MTHFR) deficiency and low dietary folate in different disorders, the association of these metabolic disturbances with a variety of congenital defects and pregnancy complications remains controversial. In this study we investigated the effects of MTHFR and dietary folate deficiency at 10.5 days post coitum (dpc) in our mouse model of mild MTHFR deficiency.METHODS:Mthfr+/+ and +/− female mice were fed a control or folic acid–deficient diet for 6 weeks, then mated withMthfr+/− males. At 10.5 dpc, embryos were examined and placentae were collected for histologic evaluation.RESULTS:Maternal MTHFR and folate deficiencies resulted in increased developmental delays and smaller embryos. We also observed a low frequency of a variety of embryonic defects in the experimental groups, such as neural tube, heart looping, and turning defects; these results mimic the low incidence and multifactorial nature of these anomalies in humans. Folate‐deficient mice also had increased embryonic losses and severe placental defects, including placental abruption and disturbed patterning of placental layers. Folate‐deficient placentae had decreased ApoA‐I expression, and there was a trend toward a negative correlation between ApoA‐I expression with maternal homocysteine concentrations.CONCLUSIONS:Our study provides biological evidence linking maternal MTHFR and dietary folate deficiencies to adverse pregnancy outcomes in mice. It underscores the importance of folate not only in reducing the incidence of early embryonic defects, but also in the prevention of developmental delays and placental abnormalities that may increase susceptibility to other defects and to reproductive complications. Birth Defects Research (Part A), 2009. © 2009 Wiley‐Liss, Inc.
Constructing virtual hydraulic circuits using Flash
Authors: Gao Zhenguo , Wang Chunsheng 
Published: February 2009

AbstractVirtual hydraulic circuits can be valuable complements to hydraulic circuit experiment education since that they can relieve the problem of lack of physical hydraulic experiment equipments. Flash is the most widely used software for creating plane animations for education. In this article, the process of constructing a virtual hydraulic circuit using Flash is demonstrated in detail by dividing the whole process into four steps: (1) designs the structure of the virtual hydraulic circuit, (2) creates virtual hydraulic component Flash symbols, (3) constructs the virtual hydraulic circuit Flash movie using the created virtual hydraulic component Flash symbols, and (4) synthesizes the mathematical models of the whole virtual hydraulic circuit, and implements numerical simulation algorithms using ActionScript language to drive the virtual hydraulic circuit according to the mathematical models. © 2009 Wiley Periodicals, Inc. Comput Appl Eng Educ 18: 356–374, 2010; Published online in Wiley InterScience (www.interscience.wiley.com); DOI 10.1002/cae.20267
Cover Picture: Highly Water‐Soluble, Fluorescent, Conjugated Fluorene‐Based Glycopolymers with Poly(ethylene glycol)‐Tethered Spacers for Sensitive Detection of Escherichia coli (Chem. Eur. J. 10/2009)
Authors: Xue Cuihua , Velayudham Singaravelu , Johnson Steve , Saha Ratul , Smith Adrian , Brewer Wilbel , Murthy Pushpalatha , Bagley Susan T. , Liu Haiying 
Published: February 2009

AbstractDetection of pathogenic Escherichia coli is of the utmost importance in the food industry, water and environmental quality control, and clinical diagnosis for health and safety reasons. In their Full Paper on page 2289 ff., H. Liu et al. describe glycopolymers, with the use of poly(ethylene glycol), as glycoside‐tethered spacers that offer the sensitive detection of E. coli, as a result of the significantly reduced steric binding hindrance of the polymeric carbohydrates to the bacterial pili.magnified image
Diagnosis of renal osteodystrophy among chronic kidney disease patients
Authors: Khan Samina S. , Iraniha Mohammad R. 
Published: February 2009

AbstractOBJECTIVEThe purpose of this review was to study the prevalence of and establish an association between biochemical markers and the underlying rate of bone turnover in renal osteodystrophy.METHODSUsing the PubMed database, we undertook a systematic review of literature using studies that included bone histology in combination with serum biochemical markers among chronic kidney disease (CKD) patients, published between 1985 and 2007. Studies having at least 3 of 7 serum biochemical markers were chosen for this review.RESULTSOf the dialysis patients who were recipients of 1,701 bone biopsies, 41% had hyperparathyroid bone disease, 5% had osteomalacia, and 33% had adynamic bone disease. Among CKD patients not on dialysis, of a total of 1,316 bone biopsies, 34% had hyperparathyroid bone disease, 19% had osteomalacia, and 8% had adynamic bone disease. Dialysis patients who had high‐turnover bone disease compared with those with low bone turnover had significantly higher levels of parathyroid hormone, serum alkaline phosphatase, bone‐specific alkaline phosphatase, and osteocalcin. A similar relationship was observed among CKD patients not on dialysis. There was significant individual variation in bone turnover biochemical markers.CONCLUSIONSA combination of serum biochemical markers might predict underlying renal osteodystrophy better than would individual biochemical markers. A predictive model using bone histology and biochemical markers can be developed in the future.
Why can't Johnny remember the basic facts?
Authors: Baroody Arthur J. , Bajwa Neet Priya , Eiland Michael 
Published: February 2009

AbstractMemorizing the basic number combinations, such as 9 + 7 = 16 and 16 − 9 = 7, is a punishing and insurmountable task for children with difficulties learning mathematics. Two perspectives on such learning lead to different conclusions about the primary source of this key learning difficulty. According to the conventional wisdom (the Passive Storage View), memorizing a basic fact is a simple form of learning—merely forming and strengthening an association between an expression and its answer. The two primary reasons this simple form of learning does not occur are inadequate practice or, in cases where adequate practice has been provided, a defect in the learner. According to the number sense perspective (Active Construction View), memorizing the basic combinations entails constructing a well‐structured or ‐connected body of knowledge that involves patterns, relations, algebraic rules, and automatic reasoning processes, as well as facts. In effect, fluency with the basic number combinations begins with and grows out of number sense. Aspects of number sense critical to such fluency begin to develop in the preschool years. According to the Active Construction View, the primary cause of problems with the basic combinations, especially among children at risk for or already experiencing learning difficulties, is the lack of opportunity to develop number sense during the preschool and early school years. © 2009 Wiley‐Liss, Inc. Dev Disabil Res Rev 2009;15:69–79.
Mathematical development in spina bifida
Authors: English Lianne H. , Barnes Marcia A. , Taylor Heather B. , Landry Susan H. 
Published: February 2009

AbstractSpina bifida (SB) is a neural tube defect diagnosed before or at birth that is associated with a high incidence of math disability often without co‐occurring difficulties in reading. SB provides an interesting population within which to examine the development of mathematical abilities and disability across the lifespan and in relation to the deficits in visual‐spatial processing that are also associated with the disorder. An overview of math and its cognitive correlates in preschoolers, school‐age children and adults with SB is presented including the findings from a longitudinal study linking early executive functions in infancy to the development of later preschool and school age math skills. These findings are discussed in relation to socio‐historical perspectives on math education and implications for intervention and directions for further research are presented. © 2009 Wiley‐Liss, Inc. Dev Disabil Res Rev 2009;15:28–34.
Mathematical learning disability in girls with Turner syndrome: A challenge to defining MLD and its subtypes
Authors: Mazzocco Michèle M.M. 
Published: February 2009

AbstractTurner syndrome is a common disorder with a prevalence of 1:2,500 live female births. Although not associated with mental retardation, there is an increased risk of learning difficulties in this population. In particular, mathematical learning difficulties among girls with Turner syndrome are prevalent, significant, and persistent. As such, the study of mathematical performance in girls with Turner syndrome presents opportunities to advance our knowledge of mathematics ability, disability, and disability subtypes. Moreover, the Turner syndrome phenotype illustrates the challenges faced when defining mathematical learning disability (MLD) and characterizing MLD subtypes because the cognitive phenotype is aligned with several proposed MLD subtypes. There is some evidence linking MLD in Turner syndrome with spatial deficits, with executive dysfunction, and with deficient numerosity skills. Yet there is also conflicting evidence as to whether any of these explanations underlies MLD in Turner syndrome. Most mathematical difficulties in girls with Turner syndrome, as a group, occur on timed tests or on complex problems. On untimed tests, achievement test scores may be age appropriate. Therefore, the inclusion of MLD in the Turner syndrome cognitive phenotype reminds us that we cannot rule out MLD solely on the basis of performance on an untimed calculations subtest, and it poses a challenge to the widespread practice in which many researchers engage, that is, defining MLD on the basis of broad mathematics achievement test outcomes. © 2009 Wiley‐Liss, Inc. Dev Disabil Res Rev 2009;15:35–44.
Principal component analysis for compositional data with outliers
Authors: Filzmoser Peter , Hron Karel , Reimann Clemens 
Published: February 2009

AbstractCompositional data (almost all data in geochemistry) are closed data, that is they usually sum up to a constant (e.g. weight percent, wt.%) and carry only relative information. Thus, the covariance structure of compositional data is strongly biased and results of many multivariate techniques become doubtful without a proper transformation of the data. The centred logratio transformation (clr) is often used to open closed data. However the transformed data do not have full rank following a logratio transformation and cannot be used for robust multivariate techniques like principal component analysis (PCA). Here we propose to use the isometric logratio transformation (ilr) instead. However, the ilr transformation has the disadvantage that the resulting new variables are no longer directly interpretable in terms of the originally entered variables. Here we propose a technique how the resulting scores and loadings of a robust PCA on ilr transformed data can be back‐transformed and interpreted. The procedure is demonstrated using a real data set from regional geochemistry and compared to results from non‐transformed and non‐robust versions of PCA. It turns out that the procedure using ilr‐transformed data and robust PCA delivers superior results to all other approaches. The examples demonstrate that due to the compositional nature of geochemical data PCA should not be carried out without an appropriate transformation. Furthermore a robust approach is preferable if the dataset contains outliers. Copyright © 2009 John Wiley & Sons, Ltd.
Extreme limit distribution of truncated models for daily rainfall
Authors: Hernández Aracelis , Guenni Lelys , Sansó Bruno 
Published: February 2009

AbstractWe propose truncated and power‐transformed (TPT) models for daily rainfall and we derive the generalized extreme value (GEV) limit distributions for these models. We find that these limit distributions belong to the domain of attraction of the Fréchet family when the parent distribution of the daily values is a TPT t‐Student model. In this case, the shape parameter of the limiting GEV model depends on the degrees of freedom and the power transformation parameter. When the parent distribution of the daily values is a TPT Normal model, the limiting GEV model is independent of the parameters of the parent model. We perform a detailed inference and predictive analysis to verify these theoretical results using a Bayesian approach. Markov Chain Monte Carlo methods (MCMC) were used to estimate the posterior distribution of the parameters of the t‐Student model for daily rainfall on one hand, and to estimate the posterior distribution of the parameters of the GEV model for the annual maxima on the other hand. Numerical results are presented for two locations: Maiquetía (Vargas State), and La Mariposa (Miranda State), Venezuela. Simulations from the predictive distribution of the daily values suggest a good approximation between the extreme distribution of the TPT t‐Student model and the Fréchet model found by standard extreme value limit theory. Copyright © 2009 John Wiley & Sons, Ltd.
Membrane‐Less Biofuel Cell Based on Cellobiose Dehydrogenase (Anode)/Laccase (Cathode) WiredviaSpecific Os‐Redox Polymers
Authors: Stoica L. , Dimcheva N. , Ackermann Y. , Karnicka K. , Guschin D. A. , Kulesza P. J. , Rogalski J. , Haltrich D. , Ludwig R. , Gorton L. , Schuhmann W. 
Published: February 2009

AbstractA membrane‐free biofuel cell (BFC) is reported based on enzymes wired to graphite electrodes by means of Os‐complex modified redox polymers. For the anode cellobiose dehydrogenase (CDH) is used as a biocatalyst whereas for the cathode a laccase was applied. This laccase is a high‐potential laccase and hence able to reduce O2to H2O at a formal potential higher than +500 mVversusAg/AgCl. In order to establish efficient electrochemical contact between the enzymes and graphite electrodes electrodeposition polymers containing Os‐complex with specifically designed monomer compositions and formal potentials of the coordinatively bound Os‐complex were synthesised and used to wire the enzymes to the electrodes. The newly designed CDH/Os‐redox polymer anode was characterised at different pH values and optimised with respect to the nature of the polymer and the enzyme‐to‐polymer ratio. The resulting BFC was evaluated running on β‐lactose as a fuel and air/O2as an oxidising agent. The power output, the maximum current density and the electromotor force (Eemf) were found to be affected by the pH value, resulting in a maximum power output of 1.9 μW cm–2reached at pH 4.3, a maximum current density of about 13 μA cm–2at pH 3.5, and the highestEemfapproaching 600 mV at pH 4.0.
Hemoproteins in Design of Biofuel Cells
Authors: Ramanavicius A. , Ramanaviciene A. 
Published: February 2009

AbstractDirect electron transfer (DET) is a unique feature of some enzymes. The possibility of DET between enzymes and the electrode surface could pave the way for superior reagentless, noncompartmentised, mediator‐free biofuel cells, as it obviates the need for mediators and allows an efficient transduction of the electrical current. DET is highly beneficial in the development of enzymatic and microbial biofuel cells. In this review article, hemoproteins, which are able to directly transfer electrons to the surfaces of conducting supports, are briefly overviewed and characterised. The main focus is laid on the application of heme‐c containing enzymes in biofuel cell design. Some historical steps and recent developments in biofuel cell design are presented in this article. Various designs of biofuel cells are overviewed. Possible applications of biofuel cells are presented and/or predicted and discussed. Problems and challenges in biofuel cell design and application are identified while possible directions to solve recent problems in biofuel cell development are discussed. The application of enzymatic biofuel cells as model systems and tools for advanced study of bioelectronics' properties of enzymes is predicted.
Simultaneous expansions of microRNAs and protein‐coding genes by gene/genome duplications in early vertebrates
Authors: Gu Xun , Su Zhixi , Huang Yong 
Published: February 2009

AbstractDoes miRNAs underlie the origin of organismal complexity in vertebrates? The current controversy is focused on whether the inventory of vertebrate miRNAs can be explained by the classical two‐round genome duplications. We estimate the age distribution of vertebrate miRNA duplication events, showing the evolutionary scenario that gene/genome duplications in the early stage of vertebrates may expand the protein‐encoding genes and miRNAs simultaneously. We further speculate that genetically lying behind the evolution of vertebrate complexity may be the proteome doubling and alterations of the epigenetic (including miRNA) machinery. J. Exp. Zool. (Mol. Dev. Evol.) 312B:164–170, 2009. © 2009 Wiley‐Liss, Inc.
The phyllolepid placoderm Cowralepis mclachlani: Insights into the evolution of feeding mechanisms in jawed vertebrates
Authors: Carr Robert K. , Johanson Zerina , Ritchie Alex 
Published: February 2009

AbstractRemarkably preserved specimens of Cowralepis mclachlani Ritchie, 2005 (Proc Linn Soc NSW 126:215–259) (Phyllolepida, Placodermi) represent a unique ontogenetic sequence adding to our understanding of anatomy, function, and phylogeny among basal jawed vertebrates (gnathostomes). A systematic review demonstrates that the Phyllolepida are a subgroup of the Arthrodira. Consideration of visceral and neurocranial characters supports the hypothesis that placoderms are the sister group to remaining gnathostomes. Placoderms possess, as adult plesiomorphic features, a number of characters that are only seen in the development of extant gnathostomes—a peramorphic shift relative to placoderms. Developmental evidence in vertebrates leads to a revised polarity of character transitions. These include 1) hyomandibula‐neurocranium and ventral parachordal‐palatoquadrate articulations (vertebrate synapomorphies); 2) jointed pharynx, paired basibranchials, anterior ethmoidal‐palatoquadrate articulation, short trabeculae cranii, and anterior and posterior neurocranial fissures (gnathostome synapomorphies); and 3) fused basibranchials, dorsal palatoquadrate‐neurocranium articulation, loss of the anterior neurocranial fissure, elongated trabeculae cranii, and transfer of the ventral parachordal‐palatoquadrate articulation to the trabeculae (crown group gnathostomes). The level of preservation in C. mclachlani provides the basis for a reinterpretation of phyllolepid anatomy and function. Cowralepis mclachlani possesses paired basibranchials allowing the reinterpretation of the visceral skeleton in other placoderms. Mandible depression in C. mclachlani follows an osteichthyan pattern and the ventral visceral skeleton acts as a functional unit. Evidence for hypobranchial musculature demonstrates the neural crest origin of the basibranchials and that Cowralepis was a suction feeder. Finally, the position of the visceral skeleton relative to the neurocranium in placoderms parallels the condition in selachians and osteichthyans, but differs in the elongation of the occiput. The cucullaris fossa of placoderms (interpreted as a site of muscle attachment) is shown to represent, in part, the parabranchial chamber. J. Morphol., 2009. © 2009 Wiley‐Liss, Inc.
Osteogenic potential and responsiveness to leptin of mesenchymal stem cells between postmenopausal women with osteoarthritis and osteoporosis
Authors: Zhang Zi‐Ming , Jiang Lei‐Sheng , Jiang Sheng‐Dan , Dai Li‐Yang 
Published: February 2009

AbstractThe aim of this study was to compare the osteogenic potential and responsiveness to leptin of mesenchymal stem cells (MSCs) from bone marrow between postmenopausal women with osteoarthritis (OA) and osteoporosis (OP). MSCs of the proximal femur from OA and OP donors were cultured under control and different experimental mediums. After verifying the availability of primary cells, their osteogenic potential and responsiveness to leptin were compared between two groups. Similar patterns of cell growth were shown in both OA and OP groups. However, after the sixth passage, the viability of undifferentiated cells decreased more in OP than in OA donors. Under the same osteogenic supplements condition, the mRNA expression of osteogenesis‐specific genes, osteocalcin (OC) and alkaline phosphatase (ALP) were higher in OA group. Comparison of bone matrix mineralization was parallel to that of mRNA expression. The level of bone‐specific ALP (BAP) was higher in cells from donors with OA, whereas osteoprotegerin (OPG) was higher in OP group. This difference in BAP expression proved to be insignificant after the administration of leptin. Although leptin upregulated the expression of OPG, a significant difference still existed between OA and OP. In conclusion, differential osteogenic potential and responsiveness to leptin of MSCs were noted between postmenopausal women with OA and OP. Differential biological behavior of MSCs seems to be partly related to the different distribution of bone mass between OA and OP populations. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27: 1067–1073, 2009
Nutrient content and yield in relation to top breakover in onion developed from greenhouse‐grown transplants
Authors: Russo Vincent M 
Published: February 2009

AbstractBACKGROUND: Onions (Allium cepa L.) generally are harvested based on percentage of tops broken over. Since plant metabolism changes over time, percentage of tops broken over may be used to determine a harvest time to deliver marketable bulbs with the best nutrient content.RESULTS: The cultivars Candy and Texas Grano 1015 Y were harvested at 10%, 20%, 30%, 40% and 50% breakover in 2006 and 2007. Larger and heavier bulbs were produced by Candy and in 2006, the year with near‐normal precipitation. There was little difference in bulb size and weight due to percent breakover. Contents of chemical moieties in bulbs were affected by year, with the majority of values being higher in 2006, and there were either no differences due to cultivar, or where differences were found nitrate‐N, phosphate and sulfate contents were lower in Candy. Soluble solids content was lower in 2006 and higher in Candy. Content of nitrogen and phosphorous in a Kjeldahl digest, nitrate‐N, phosphate, potassium and sulfate were either linearly or quadratically distributed over percent breakover. Nitrite‐N, calcium, magnesium, sodium and soluble solids were randomly distributed over percent breakover. Bulb size and weight did not change from the 20% breakover point, and most of the chemical moieties analyzed, with the exception of nitrate‐ and nitrite‐N values, were highest below the 30% breakover.CONCLUSION: Harvest occurring soon after breakover begins could be beneficial in terms of nutrient content without loss of bulb size or weight. Copyright © 2009 Society of Chemical Industry