bluuebunny/crossref_metadata_2025_split huggingface dataset:
Prediction of Breeding Values and Selection Responses With Genetic Heterogeneity of Environmental Variance
Authors: Mulder H A , Bijma P , Hill W G 
Published: February 2007

Abstract
There is empirical evidence that genotypes differ not only in mean, but also in environmental variance of the traits they affect. Genetic heterogeneity of environmental variance may indicate genetic differences in environmental sensitivity. The aim of this study was to develop a general framework for prediction of breeding values and selection responses in mean and environmental variance with genetic heterogeneity of environmental variance. Both means and environmental variances were treated as heritable traits. Breeding values and selection responses were predicted with little bias using linear, quadratic, and cubic regression on individual phenotype or using linear regression on the mean and within-family variance of a group of relatives. A measure of heritability was proposed for environmental variance to standardize results in the literature and to facilitate comparisons to “conventional” traits. Genetic heterogeneity of environmental variance can be considered as a trait with a low heritability. Although a large amount of information is necessary to accurately estimate breeding values for environmental variance, response in environmental variance can be substantial, even with mass selection. The methods developed allow use of the well-known selection index framework to evaluate breeding strategies and effects of natural selection that simultaneously change the mean and the variance.
Test of Genetical Isochronism for Longitudinal Samples of DNA Sequences
Authors: Liu Xiaoming , Fu Yun-Xin 
Published: February 2007

Abstract
Longitudinal samples of DNA sequences, the DNA sequences sampled from the same population at different time points, have increasingly been used to study the evolutionary process of fast-evolving organisms, e.g., RNA virus, in recent years. We propose in this article several methods for testing genetical isochronism or detecting significant genetical heterochronism in this type of sample. These methods can be used to determine the necessary sample size and sampling interval in experimental design or to combine genetically isochronic samples for better data analysis. We investigate the properties of these test statistics, including their powers of detecting heterochronism, assuming different evolutionary processes using simulation. The possible choices and usages of these test statistics are discussed.
The Genetics of Hybrid Male Sterility Between the Allopatric Species Pair Drosophila persimilis and D. pseudoobscura bogotana: Dominant Sterility Alleles in Collinear Autosomal Regions
Authors: Chang Audrey S , Noor Mohamed A F 
Published: February 2007

Abstract
F1 hybrid male sterility is thought to result from interactions between loci on the X chromosome and dominant-acting loci on the autosomes. While X-linked loci that contribute to hybrid male sterility have been precisely localized in many animal taxa, their dominant autosomal interactors have been more difficult to localize precisely and/or have been shown to be of relatively smaller effect. Here, we identified and mapped at least four dominant autosomal factors contributing to hybrid male sterility in the allopatric species pair Drosophila persimilis and D. pseudoobscura bogotana. Using these results, we tested predictions of reduced recombination models of speciation. Consistent with these models, three of the four QTL associated with hybrid male sterility occur in collinear (uninverted) regions of these genomes. Furthermore, these QTL do not contribute significantly to hybrid male sterility in crosses between the sympatric species D. persimilis and D. pseudoobscura pseudoobscura. The autosomal loci identified in this study provide the basis for introgression mapping and, ultimately, for molecular cloning of interacting genes that contribute to F1 hybrid sterility.
The Nonmuscle Myosin Phosphatase PP1β (flapwing) Negatively Regulates Jun N-Terminal Kinase in Wing Imaginal Discs of Drosophila
Authors: Kirchner Jasmin , Gross Sascha , Bennett Daimark , Alphey Luke 
Published: February 2007

Abstract
Drosophila flapwing (flw) codes for serine/threonine protein phosphatase type 1β (PP1β). Regulation of nonmuscle myosin activity is the single essential flw function that is nonredundant with the three closely related PP1α genes. Flw is thought to dephosphorylate the nonmuscle myosin regulatory light chain, Spaghetti Squash (Sqh); this inactivates the nonmuscle myosin heavy chain, Zipper (Zip). Thus, strong flw mutants lead to hyperphosphorylation of Sqh and hyperactivation of nonmuscle myosin activity. Here, we show genetically that a Jun N-terminal kinase (JNK) mutant suppresses the semilethality of a strong flw allele. Alleles of the JNK phosphatase puckered (puc) genetically enhance the weak allele flw1, leading to severe wing defects. Introducing a mutant of the nonmuscle myosin-binding subunit (Mbs) further enhances this genetic interaction to lethality. We show that puc expression is upregulated in wing imaginal discs mutant for flw1 and pucA251 and that this upregulation is modified by JNK and Zip. The level of phosphorylated (active) JNK is elevated in flw1 enhanced by puc. Together, we show that disruption of nonmuscle myosin activates JNK and puc expression in wing imaginal discs.
Pediatric and Emergency Medicine Residents' Attitudes and Practices for Analgesia and Sedation During Lumbar Puncture in Pediatric Patients
Authors: Breakey Vicky R. , Pirie Jonathan , Goldman Ran D. 
Published: February 2007

OBJECTIVE. Analgesia and sedation for painful procedures in children are safe and effective, yet our experience is that pain management during lumbar puncture is suboptimal. We aim to document factors that influence residents' decisions to use analgesia and sedation during lumbar puncture and to compare pediatric and emergency medicine residents' practices.METHODS. A survey was developed and sent to pediatric and emergency medicine residents from across Canada that inquired about clinical practices, learning experiences, current use of analgesia and sedation for lumbar puncture, and their clinical reasoning for using or abstaining from using analgesia and sedation. The Student's t and χ2 tests were used to compare the 2 resident groups.RESULTS. Of the 374 residents to whom the survey was sent, 245 completed the survey. Pediatric residents reported performing lumbar punctures with no local anesthetic much more frequently. Pediatric residents used EMLA (AstraZeneca, Wilmington, DE) more frequently and injectable lidocaine less frequently. Pediatric residents used sedation for lumbar puncture at least once, more frequently than emergency medicine residents, and used mostly benzodiazepines. Both groups used ketamine at a similar rate. Pediatric residents reported that they witnessed adverse events of sedation more frequently. Although pediatric residents were responsible for teaching trainees the lumbar-puncture procedure significantly more frequently, they reported less educational opportunities during residency themselves and that they were less likely to recommend the use of local anesthetic during lumbar puncture when teaching the procedure.CONCLUSIONS. Several significant differences exist between the pediatric residents and emergency medicine residents we surveyed. Pediatric residents were using less injectable local anesthesia for lumbar puncture in children and more sedation for the procedure and have had notably less training in the use of sedation. Pediatric residents have more teaching responsibilities than their emergency medicine residents colleagues and are inconsistently recommending the use of local anesthetics for lumbar puncture.
Differentiating Human Embryonic Stem Cells Express a Unique Housekeeping Gene Signature
Authors: Synnergren Jane , Giesler Theresa L. , Adak Sudeshna , Tandon Reeti , Noaksson Karin , Lindahl Anders , Nilsson Patric , Nelson Deirdre , Olsson Björn , Englund Mikael C.O. , Abbot Stewart , Sartipy Peter 
Published: February 2007

Abstract
Housekeeping genes (HKGs) are involved in basic functions needed for the sustenance of the cell and are assumed to be constitutively expressed at a constant level. Based on these features, HKGs are frequently used for normalization of gene expression data. In the present study, we used the CodeLink Gene Expression Bioarray system to interrogate changes in gene expression occurring during differentiation of human ESCs (hESCs). Notably, in the three hESC lines used for the study, we observed that the RNA levels of 56 frequently used HKGs varied to a degree that rendered them inappropriate as reference genes. Therefore, we defined a novel set of HKGs specifically for hESCs. Here we present a comprehensive list of 292 genes that are stably expressed (coefficient of variation &lt;20%) in differentiating hESCs. These genes were further grouped into high-, medium-, and low-expressed genes. The expression patterns of these novel HKGs show very little overlap with results obtained from somatic cells and tissues. We further explored the stability of this novel set of HKGs in independent, publicly available gene expression data from hESCs and observed substantial similarities with our results. Gene expression was confirmed by real-time quantitative polymerase chain reaction analysis. Taken together, these results suggest that differentiating hESCs have a unique HKG signature and underscore the necessity to validate the expression profiles of putative HKGs. In addition, this novel set of HKGs can preferentially be used as controls in gene expression analyses of differentiating hESCs.
Differential Requirements for Hematopoietic Commitment Between Human and Rhesus Embryonic Stem Cells
Authors: Rajesh Deepika , Chinnasamy Nachimuthu , Mitalipov Shoukhrat M. , Wolf Don P. , Slukvin Igor , Thomson James A. , Shaaban Aimen F. 
Published: February 2007

Abstract
Progress toward clinical application of ESC-derived hematopoietic cellular transplantation will require rigorous evaluation in a large animal allogeneic model. However, in contrast to human ESCs (hESCs), efforts to induce conclusive hematopoietic differentiation from rhesus macaque ESCs (rESCs) have been unsuccessful. Characterizing these poorly understood functional differences will facilitate progress in this area and likely clarify the critical steps involved in the hematopoietic differentiation of ESCs. To accomplish this goal, we compared the hematopoietic differentiation of hESCs with that of rESCs in both EB culture and stroma coculture. Initially, undifferentiated rESCs and hESCs were adapted to growth on Matrigel without a change in their phenotype or karyotype. Subsequent differentiation of rESCs in OP9 stroma led to the development of CD34+CD45− cells that gave rise to endothelial cell networks in methylcellulose culture. In the same conditions, hESCs exhibited convincing hematopoietic differentiation. In cytokine-supplemented EB culture, rESCs demonstrated improved hematopoietic differentiation with higher levels of CD34+ and detectable levels of CD45+ cells. However, these levels remained dramatically lower than those for hESCs in identical culture conditions. Subsequent plating of cytokine-supplemented rhesus EBs in methylcellulose culture led to the formation of mixed colonies of erythroid, myeloid, and endothelial cells, confirming the existence of bipotential hematoendothelial progenitors in the cytokine-supplemented EB cultures. Evaluation of four different rESC lines confirmed the validity of these disparities. Although rESCs have the potential for hematopoietic differentiation, they exhibit a pause at the hemangioblast stage of hematopoietic development in culture conditions developed for hESCs.
Leukemia Inhibitory Factor Influences the Fate Choice of Mesenchymal Progenitor Cells
Authors: Falconi Dominic , Oizumi Kiyoshi , Aubin Jane E. 
Published: February 2007

Abstract
Osteoblasts and adipocytes derive from a common mesenchymal precursor, and in at least some circumstances, differentiation along these two lineages is inversely related. For example, we have recently observed that concomitant with inhibition of osteoblast differentiation and bone nodule formation, leukemia inhibitory factor (LIF) induces genes regulating lipid metabolism in fetal rat calvaria (RC) cell cultures. In this study, we further investigated the adipogenic capacity of LIF-treated RC cells. Quantitative analyses revealed that LIF increased the adipocyte differentiation induced by the peroxisome proliferator-activated receptor γ agonist BRL49653 (BRL) in RC cell populations. Gene expression profiling of individual RC cell colonies in untreated cells or cells treated with LIF, BRL, or combined LIF-BRL suggested that some adipocytes arose from bipotential or other primitive precursors, including osteoprogenitors, since many colonies co-expressed osteoblast and adipocyte differentiation markers, whereas some arose from other cell pools, most likely committed preadipocytes present in the population. These analyses further suggested that LIF and BRL do not act at the same stages of the mesenchymal hierarchy, but rather that LIF modifies differentiation of precursor cells, whereas BRL acts later to favor adipocyte differentiation. Taken together, our data suggest that LIF increased adipocyte differentiation at least in part by altering the fate of osteoblastic cells and their precursors.
Ambipolar Conductive 2,7‐Carbazole Derivatives for Electroluminescent Devices
Authors: Shen J.‐Y. , Yang X.‐L. , Huang T.‐H. , Lin J. T. , Ke T.‐H. , Chen L.‐Y. , Wu C.‐C. , Yeh M.‐C. P. 
Published: February 2007

AbstractA series of 2,7‐disubstituted carbazole (2,7‐carb) derivatives incorporating arylamines at the 2 and 7 positions are synthesized via palladium‐catalyzed C–N or C–C bond formation. These compounds possess glass transition temperatures ranging from 87 to 217 °C and exhibit good thermal stabilities, with thermal decomposition temperatures ranging from 388 to 480 °C. They are fluorescent and emit in the purple‐blue to orange region. Two types of organic light emitting diodes (OLEDs) were constructed from these compounds: (I) indium tin oxide (ITO)/2,7‐carb (40 nm)/1,3,5‐tris(N‐phenylbenzimidazol‐2‐yl)benzene (TPBI, 40 nm)/Mg:Ag; and (II) ITO/2,7‐carb (40 nm)/tris(8‐hydroxyquinoline) aluminum (Alq3, 40 nm)/Mg:Ag. In type I devices, the 2,7‐disubstituted carbazoles function as both hole‐transporting and emitting material. In type II devices, light is emitted from either the 2,7‐disubstituted carbazole layer or Alq3. The devices appear to have a better performance compared to devices fabricated with their 3,6‐disubstituted carbazole congeners. Some of the new compounds exhibit ambipolar conductive behavior, with hole and electron mobilities up to 10–4 cm2 V–1 s–1.
Neocortical hyperexcitability in a human case of tuberous sclerosis complex and mice lacking neuronal expression of TSC1
Authors: Wang Yanling , Greenwood Joel S. F. , Calcagnotto Maria Elisa , Kirsch Heidi E. , Barbaro Nicholas M. , Baraban Scott C. 
Published: February 2007

AbstractObjectiveTo identify brain regions, cell types, or both that generate abnormal electrical discharge in tuberous sclerosis complex (TSC). Here we examined excitatory and inhibitory synaptic currents in human tissue samples obtained from a TSC patient with no discernible cortical tubers and acute neocortical brain slices from a mouse featuring synapsin‐driven conditional deletion of a TSC1 gene. These studies were designed to assess whether TSC gene inactivation alters excitability.MethodsWe used visualized patch‐clamp (human and mouse) and extracellular field (mouse) recordings. Additional mice were processed for immunohistochemistry or Western blot analysis.ResultsDetailed anatomic studies in brain tissue sections from synapsin‐TSC1 conditional knock‐out mice failed to uncover gross anatomic defects, loss of lamination, or frank tuber formation. However, regions of abnormal and potentially activated neocortex were shown using antibodies to nonphosphorylated neurofilaments (SMI‐311) and immediate early genes (c‐Fos). Extracellular recordings from neocortical slices, examining synaptic activity in these regions, demonstrated clear differences in excitability between conditional knock‐out and age‐matched control mice. Whole‐cell patch‐clamp recordings demonstrated excitatory synaptic currents with strikingly long duration and epileptiform discharge patterns, similar to waveforms observed in our human tissue samples. These events were 1‐amino‐3‐hydroxy‐5‐methyl‐4‐isoxazolepropionate (AMPA) receptor mediated and were most prominent in neocortex. Normal‐appearing inhibitory postsynaptic currents (human) and intrinsic neuronal firing patterns (mouse) were also recorded.InterpretationThis combination of human and mouse tissue studies suggests, for the first time, that synaptic excitation is altered in a direction that favors seizure generation in TSC brain tissue regardless of cortical tubers. Ann Neurol 2007
Magnetische Nanopartikel: Synthese, Stabilisierung, Funktionalisierung und Anwendung
Authors: Lu An‐Hui , Salabas Elena Lorena , Schüth Ferdi 
Published: February 2007

AbstractDieser Aufsatz beschreibt die Synthese, Stabilisierung, Funktionalisierung und Anwendung magnetischer Nanopartikel sowie die magnetischen Eigenschaften nanostrukturierter Systeme. Fortschritte hinsichtlich der Größen‐ und Formkontrolle magnetischer Nanopartikel wurden durch Methoden wie Mitfällung, thermische Zersetzung und/oder Reduktion, micellare Synthesestrategien und Hydrothermalsynthese erzielt. Entscheidend ist immer noch der Schutz gegen Korrosion, weshalb ein Schwerpunkt auf geeignete Schutzstrategien gelegt wird – z. B. Tensid/Polymer‐, Silicat‐ und Kohlenstoff‐Beschichtung magnetischer Nanopartikel sowie ihre Einbettung in eine Matrix oder ein Trägermaterial. Geschützte magnetische Nanopartikel können als Bausteine für verschiedene funktionale Systeme verwendet werden, und ihre Anwendung in Katalyse und Biotechnologie wird ebenfalls kurz diskutiert. Zum Schluss werden einige Trends auf diesen Forschungsgebieten umrissen und Ausblicke auf zukünftige Entwicklungen gegeben.
Rheological properties of new polymer compositions for sand consolidation and water shutoff in oil wells
Authors: Lahalih S. M. , Ghloum E. F. 
Published: February 2007

AbstractThe rheological properties of some newly developed polymer compositions have been investigated with and without crosslinking. These polymer compositions were developed as a water shutoff and sand consolidation treatment agents for producing oil and gas wells. The effects of several variables on the rheology of the compositions were evaluated over a wide range of temperatures (25–110°C), shear rates (0–500 s−1), brine percentages (0–15%), crosslinker types and concentrations (0–3%), and polymer concentrations (6–50%). It was found that increasing the shear rate from 0 s−1 to 100 s−1 caused shear thinning and reduction of the viscosity of the dilute solutions (6–13%) from 25 cP to ∼ 3 cP at 80°C. In contrast, for the concentrated solutions (20–50%), the viscosity dropped slightly in the shear rate range 0–10 s−1, and subsequently decreased more slowly up to shear rates of 500 s−1. The viscosities of all polymer solutions dropped by a factor of 2 as the brine concentration increased from 0% to 15%. Finally, aging time coupled with shear rates and higher percentages of crosslinkers accelerate the buildup of viscosity and gelation time of the polymer compositions. For concentrated solutions, shear rates ranging within 0–200 s−1 accelerated gelation time from 9.75 h to 2–3 h, when they were sheared at 80°C. The polymeric solutions exhibited Newtonian, shear‐thinning (pseudo‐plastic), and shear‐thickening (dilatant) behavior, depending on the concentration, shear rate, and other constituents. In most cases, the rheological behavior could be described by the power law. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Preparation mechanism and characterization of a novel, regulable hollow phenolic fiber
Authors: Zhang Dongqing , Shi Jingli , Guo Quangui , Song Yan , Liu Lang , Zhai Gengtai 
Published: February 2007

AbstractA novel hollow phenolic fiber was successfully prepared by the dissolution of the uncrosslinked core of the partially crosslinking spun filament derived from the melt spinning of the phenolic resin. A series of hollow phenolic fibers with various degrees of hollowness were obtained through different preparation processes. The hollow phenolic fibers were characterized with scanning electron microscopy, infrared spectrometry, and thermogravimetric analysis. The formation of the hollow core in the hollow phenolic fibers was attributed to partial crosslinking of the filaments during the curing process; the prepared hollow phenolic fibers had high crosslinkage after the second cure, their thermal stability was as excellent as that of the solid phenolic fiber, and their hollowness could be regulated from 5 to 85%. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Conservation and management of the rivers of the Kruger National Park: Suggested methods for calculating instream flow needs
Authors: O'Keeffe Jay , Davies Bryan 
Published: February 2007

Abstract1. Six major river systems flow west to east across the Kruger National Park (South Africa). All arise outside the western boundary of the KNP, and are outside the jurisdiction of the Park authorities.2. Growing human populations to the west of the Park are placing increasing demands on the water resources of these rivers, and a variety of artificial changes threaten the ecological integrity of the rivers.3. As a result, the Luvuvhu and Letaba Rivers to the north no longer have a perennial flow, while the flow of the Crocodile River on the southern boundary of the Park has been regulated to a more constant regime due to irrigation demands. The Letaba, Olifants, and Crocodile Rivers all receive diverse pollutants. The Sabie River, at present the least disturbed system, and biologically the most diverse in South Africa, is threatened with multiple regulation within the next five years.4. The paper describes the development of initial protocols for the assessment of instream flow needs for the Luvuvhu and Sabie Rivers. These methods require an extension of existing methods developed in the USA to ensure the maintenance of ecological processes, rather than the maintenance of single target species.5. Two methods are described: one that identifies the consumptive and non‐consumptive water requirements of the rivers, adding all consumptive to the limiting non‐consumptive quantity to give a base‐flow requirement.6. A second method uses a conservation status model to assess the ecological consequences of flow reductions generated through a hydrological model, in response to different impoundment conditions.7. Both methods are successful in appropriate circumstances, but we conclude that the proposed impoundment and agricultural development of the Sabie River, in particular, is an inappropriate use of this unique resource, and that the catchment would be more advantageously developed for tourism, recreation, and nature conservation.