bluuebunny/crossref_metadata_2025_split huggingface dataset:
Alternative Lengthening of Telomeres in Human Glioma Stem Cells
Authors: Silvestre David C. , Pineda José R. , Hoffschir Françoise , Studler Jeanne-Marie , Mouthon Marc-André , Pflumio Françoise , Junier Marie-Pierre , Chneiweiss Hervé , Boussin François D. 
Published: January 2011

AbstractCancer stem cells are increasingly recognized as major therapeutic targets. We report here the isolation of glioma stem cells (GSCs) maintaining telomere length through a telomerase-independent mechanism known as alternative lengthening of telomeres (ALTs). TG20 cells were isolated from a glioblastoma multiforme, which had the ALT phenotype. They have no detectable telomerase activity and extremely long and heterogeneous telomeres colocalizing with promyelocytic leukemia bodies. The cancer stem cell potential of TG20 cells was confirmed based on their expression of neural stem cell markers, their capacity of in vitro long-term proliferation and to form intracranial tumors in immune-deficient mice. Interestingly, we found that both in vitro and in vivo TG20 cells were significantly more resistant to ionizing radiation than GSCs with telomerase activity. Analysis of DNA damage foci, DNA double-strand breaks repair, and chromosome instability suggest that radiation resistance was related to interference of ALT pathway with DNA damage response. Therefore, our data show for the first time that the ALT pathway can confer to cancer stem cells the capacity to sustain long-term proliferation as telomerase activity and importantly may also affect treatment efficiency. TG20 cells are thus the first cellular model of GSCs displaying ALT and should prove to be useful for the development of specific treatment strategies.
Correlation between pre‐ and postnatal cerebral magnetic resonance imaging
Authors: Dhouib A. , Blondiaux E. , Moutard M. L. , Billette de Villemeur T. , Chalard F. , Jouannic J. M. , Ducou le Pointe H. , Garel C. 
Published: January 2011

AbstractObjectivesTo evaluate the diagnostic accuracy of fetal cerebral magnetic resonance imaging (MRI) on a large cohort and to compare pre‐ and postnatal MRI data.MethodsThis prospective study included all cases referred to our unit for fetal cerebral MRI examination between June 2006 and December 2009 and which underwent at least one postnatal MRI examination. Cases in which there was termination of pregnancy, fetal death or stillbirth were excluded. The pre‐ and postnatal diagnoses established by MRI were compared and divided into five subgroups: same diagnosis on pre‐ and postnatal MRI (Group 1); same diagnosis but different appearance related to the natural course of the disease (Group 2); different diagnosis (related to limitations of fetal MRI) (Group 3); same diagnosis but with additional findings discovered on postnatal MRI examination (Group 4); or same diagnosis but different appearance related to the natural course of the disease (as in Group 2) and associated with additional findings discovered on postnatal MRI examination (Group 5). The prognostic impact of a possible disagreement between pre‐ and postnatal findings was evaluated.ResultsOne hundred fetuses were included. Fetal MRI was performed at a mean gestational age of 33 (range, 24–39) weeks and postnatal MRI at a mean age of 3.5 months. There were 53 cases classified as Group 1, 32 in Group 2, four in Group 3, 10 in Group 4 and one in Group 5. Thus, in 15 cases (Groups 3–5), there were discrepancies between pre‐ and postnatal findings (mostly related to corpus callosum anatomy, cortical and migration disorders). The discrepancy was judged to have a prognostic impact in 9/15 cases. Two postnatal MRI examinations were performed in eight cases, in one of which the second examination showed subependymal heterotopia which were not detectable on the first examination.ConclusionPre‐ and postnatal MRI data showed good agreement in 85% of cases. There was disagreement with a prognostic impact in 9% of cases. Copyright © 2011 ISUOG. Published by John Wiley & Sons, Ltd.
Youth as content producers in a niche social network site
Authors: Greenhow Christine 
Published: January 2011

AbstractMost U.S. teenagers participate in online social network sites, devoting hours to these networks, often at the expense of other leisure‐time activities. This article describes young people's activities within one topic‐focused niche network, outlining its unique features and the role of young people as content producers within and beyond the space. Links between youth's online contributions and their interest, self‐expression, social connections, and civic involvement are discussed.
“MXing it up”: How African adolescents may affect social change through mobile phone use
Authors: Napolitano Christopher M. 
Published: January 2011

AbstractThis chapter outlines mobile phone use among African (particularly South African) adolescents. With an estimated 350 million active mobile phone subscriptions, improving network infrastructure, low‐cost Internet‐ready handsets, innovative programs and applications, mobiles in Africa, and their increasingly younger, increasingly poorer, and increasingly savvy users have the potential to act as conduits for local and regional socially just change. This broad‐based connectedness not only provides access to information, but also, and crucially, connects individuals and their social, intellectual, and financial capital. It may represent a powerful, transformative shift in a region where access to similar technologies was historically limited to a privileged few. In order to best leverage these developments and opportunities to promote socially just change, I argue that future mobile‐based programs or initiatives in the region should be based in both contemporary developmental systems theory as well as current, popular mobile applications and services.
Cadmium(II) Complexes with 2‐Hydroxy‐1‐naphthoate Ligand: Syntheses, Crystal Structures, and Emission Properties
Authors: Hu Min , Yang Xiao‐Gang , Zhang Qiang , Zhou Li‐Ming , Fang Shao‐Ming , Liu Chun‐Sen 
Published: January 2011

AbstractTwo new CdII complexes [Cd(L)2(phen)]2 (1) and {Cd(L)2(4bpy)1.5}∞ (2) (L = 2‐hydroxy‐1‐naphthoate, phen = 1,10‐phenanthroline, and 4bpy = 4,4′‐bipyridine) were prepared by slow solvent evaporation from mixtures of 2‐hydroxy‐1‐naphthoic acid (HL) and Cd(ClO4)2·6H2O in the presence of auxiliary phen and 4bpy co‐ligands. Single‐crystal X‐ray analyses show that complex 1 features a dinuclear structure, which is assembled into a one‐dimensional (1D) chain, and further into a two‐dimensional (2D) network by intermolecular π···π stacking and C–H···π supramolecular interactions. Complex 2 has a 1D ladder‐like chain, which is further interlinked to form a 2D network by the co‐effects of the interchain C–H···O hydrogen bonds as well as C–H···π interactions. The structural differences between 1 and 2 are attributed to the different N‐donor auxiliary ligands, phen for 1 and 4bpy for 2. Moreover, complexes 1 and 2 exhibit strong solid‐state luminescences at room temperature, which mainly originate from the intraligand π → π* transitions of L.
Process of Formation of the Aurivillius Phase Bi3NbTiO9 and Its Substitutes
Authors: Missyul Alexander B. , Kuzmova Tatiana G. , Zvereva Irina A. 
Published: January 2011

AbstractTwo series of the magnetically substituted Aurivillius phases, Bi3NbTi1–xMnxO9 and Bi2LnNbTiO9 (Ln = Nd–Ho), were synthesized. The substitution was found to be limited in both cases. The formation mechanism of the unsubstituted compound Bi3NbTiO9 was proposed on the basis of both isothermal and constant rate heating data. The stability of the derivatives of the intermediate compound Bi4Ti3O12 appears to be responsible for the observed substitution limits. The kinetics of formation of Bi3NbTiO9 from the binary oxides and the intermediate compounds were studied.
Safe Limited-Open Carpal Tunnel Release in the Presence of Aberrant Anatomy
Authors: Gannon Caitlin R. , Harlan Jill , Baratz Mark E. 
Published: January 2011

Purpose The presence of aberrant anatomy during a limited-open carpal tunnel release does not require conversion to an open procedure. We describe the occurrence of aberrant anatomy seen during limited-open carpal tunnel release, and suggest the safest way to proceed with carpal tunnel release once aberrant anatomy is encountered. Methods A retrospective chart review was completed for patients who underwent limited-open carpal tunnel release between January 2000 and June 2007. The surgical record was examined to determine if any aberrant anatomy was encountered during the procedure. Results Of the 1,227 hands operated on, 69 anomalies were identified. Two carpal tunnel releases were converted to open releases after it was determined that the aberrant motor branches precluded safe release with a limited-open technique Conclusions An understanding of anatomical variations combined with vigilance and careful dissection enhances the chance for safe and effective limited-open carpal tunnel release.
Ethische Aspekte von Versorgungsgerechtigkeit
Authors: Wilp Thomas 
Published: January 2011

Einleitung
Das ethische Problem der Versorgungsgerechtigkeit im Gesundheitswesen ist im Wesentlichen ein Verteilungsproblem. Die Debatte um die Frage der Verteilungsgerechtigkeit wird seit Jahren kontrovers geführt. Von politischer Seite wird derzeit das ökonomische Wettbewerbsprinzip zur Grundlage der Gesundheitsversorgung erklärt. Was bedeutet dieses für das deutsche Gesundheitssystem und wie wirkt sich dieses auf die ethischen Ansprüche eines solidarischen Gesundheitssystems aus?
IRRIGATION WATER PRODUCTIVITY AS AFFECTED BY WATER MANAGEMENT IN A SMALL-SCALE IRRIGATION SCHEME IN THE BLUE NILE BASIN, ETHIOPIA
Authors: DERIB SISAY DEMEKU , DESCHEEMAEKER KATRIEN , HAILESLASSIE AMARE , AMEDE TILAHUN 
Published: January 2011

SUMMARYIn Ethiopia, irrigation is mainly implemented in small-scale irrigation schemes, which are often characterized by low water productivity. This study reports on the efficiency and productivity of a typical small-scale irrigation scheme in the highlands of the Blue Nile, Ethiopia. Canal water flows and the volume of irrigation water applied were measured at field level. Grain and crop residue biomass and grass biomass production along the canals were also measured. To triangulate the measurements, the irrigation farm management, effects of water logging around irrigation canals, farm water distribution mechanisms, effects of night irrigation and water losses due to soil cracking created by prolonged irrigation were closely observed. The average canal water loss from the main, the secondary and the field canals was 2.58, 1.59 and 0.39 l s−1 100 m−1, representing 4.5, 4.0 and 26% of the total water flow respectively. About 0.05% of the loss was attributed to grass production for livestock, while the rest was lost through evaporation and canal seepage. Grass production for livestock feed had a land productivity of 6190.5 kg ha−1 and a water productivity of 0.82 kg m−3. Land productivity for straw and grain was 2048 and 770 kg ha−1, respectively, for teff, and 1864 kg ha−1 and 758 kg ha−1, respectively, for wheat. Water productivities of the crops varied from 0.2 to 1.63 kg m−3. A significant volume of water was lost from small-scale irrigation systems mainly because farmers' water application did not match crop needs. The high price incurred by pumped irrigation positively affected water management by minimizing water losses and forced farmers to use deficit irrigation. Improving water productivity of small-scale irrigation requires integrated interventions including night storage mechanisms, optimal irrigation scheduling, empowerment of farmers to maintain canals and proper irrigation schedules.
LIVESTOCK WATER PRODUCTIVITY IN A WATER STRESSED ENVIRONMENT IN NORTHERN ETHIOPIA
Authors: MEKONNEN SEMIRA , DESCHEEMAEKER KATRIEN , TOLERA ADUGNA , AMEDE TILAHUN 
Published: January 2011

SUMMARYAgricultural systems of Northern Ethiopia are under pressure from demographic expansion leading to land degradation and increasing water scarcity. Livestock water productivity (LWP) is an important component in improving overall productivity in mixed crop-livestock systems. The objective of the study was to characterize the existing farming system in a typical water stressed environment in the Ethiopian highlands in terms of crop and livestock production and to assess LWP at household level. To this end, the characteristic watershed of Lenche Dima watershed was chosen. An exploratory assessment of LWP variables and potential differences between farmers' wealth classes was conducted based on a survey of 54 sample households and focus group discussions. LWP was determined as the ratio of beneficial outputs over used water. We used market values of livestock products and services to unify the livestock outputs. Water used to produce the livestock outputs was determined based on water consumption to produce the feed. The overall water used per household for livestock production ranged from 3079 ± 2335 (s.d.) m3per year to 11 975 ± 4080 (s.d.) m3per year for poor and better-off households, respectively. If fully valued as fuel and fertilizer, manure contributed an overall 34% of the total financial livestock output, followed by draught power (22%), transport (17%) and milk production (16%). LWP ranged from 0.07 to 0.09 US$ m−3and was not significantly different between farmers' wealth classes. The small differences were an indication that all farmer types had very limited access to potential LWP improvements through increased feed quality and quantity, improved animal husbandry and better veterinary care.
Parasite-induced changes in the diet of a freshwater amphipod: field and laboratory evidence
Authors: MÉDOC V. , PISCART C. , MAAZOUZI C. , SIMON L. , BEISEL J.-N. 
Published: January 2011

SUMMARYTrophically transmitted parasites are likely to strongly influence food web-structure. The extent to which they change the trophic ecology of their host remains nevertheless poorly investigated and field evidence is lacking. This is particularly true for acanthocephalan parasites whose invertebrate hosts can prey on other invertebrates and contribute to leaf-litter breakdown. We used a multiple approach combining feeding experiments, neutral lipids and stable isotopes to investigate the trophic ecology of the freshwater amphipodGammarus roeseliparasitized by the bird acanthocephalanPolymorphus minutus. Infected compared to uninfected amphipods consumed as many dead isopods, but fewer live isopods and less leaf material. Infection had no influence on the total concentration of neutral lipids. Contrary to what we expected based on laboratory findings, the nitrogen isotope signature, which allows for the estimation of consumer's trophic position, was not influenced by infection status. Conversely, the carbon isotope signature, which is used to identify food sources, changed with infection and suggested that the diet of infectedG. roeseliincludes less perilithon (i.e. fixed algae on rocks, stones) but more terrestrial inputs (e.g. leaf material) than that of uninfected conspecifics. This study shows evidence of changes in the trophic ecology ofP. minutus-infectedG. roeseliand we stress the need to complement feeding experiments with field data when investigating top-down effects of infection in an opportunistic feeder which adapts its diet to the available food sources.
Molecular identification ofCryptosporidium parvumfrom avian hosts
Authors: QUAH J. X. , AMBU S. , LIM Y. A. L. , MAHDY M. A. K. , MAK J. W. 
Published: January 2011

SUMMARYCryptosporidiumspecies are protozoan parasites that infect humans and a wide variety of animals. This study was aimed at identifyingCryptosporidiumspecies and genotypes isolated from avian hosts. A total of 90 samples from 37 different species of birds were collected throughout a 3-month period from April 2008 to June 2008 in the National Zoo of Kuala Lumpur, Malaysia. Prior to molecular characterization, all samples were screened forCryptosporidiumusing a modified Ziehl-Neelsen staining technique. Subsequently samples were analysed with nested-PCR targeting the partial SSU rRNA gene. Amplicons were sequenced in both directions and used for phylogenetic analysis using Neighbour-Joining and Maximum Parsimony methods. Although 9 (10%) samples were positive forCryptosporidiumvia microscopy, 8 (8·9%) produced amplicons using nested PCR. Phylogenetic trees identified all the isolates asCryptosporidium parvum. AlthoughC. parvumhas not been reported to cause infection in birds, and the role of birds in this study was postulated mainly as mechanical transporters, these present findings highlight the significant public health risk posed by birds that harbour the zoonotic species ofCryptosporidium.
RepRap – the replicating rapid prototyper
Authors: Jones Rhys , Haufe Patrick , Sells Edward , Iravani Pejman , Olliver Vik , Palmer Chris , Bowyer Adrian 
Published: January 2011

SUMMARYThis paper presents the results to date of the RepRap project – an ongoing project that has made and distributed freely a replicating rapid prototyper. We give the background reasoning that led to the invention of the machine, the selection of the processes that we and others have used to implement it, the designs of key parts of the machine and how these have evolved from their initial concepts and experiments, and estimates of the machine's reproductive success out in the world up to the time of writing (about 4500 machines in two and a half years).
The von Neumann threshold of self-reproducing systems: theory and application
Authors: Kabamba Pierre T. , Owens Patrick D. , Ulsoy A. Galip 
Published: January 2011

SUMMARYThis paper is devoted to the study of systems of entities that are capable of generating other entities of the same kind and, possibly, self-reproducing. The main technical issue addressed is to quantify the requirements that such entities must meet to be able to produce a progeny that is not degenerative, i.e., that has the same reproductive capability as the progenitor. A novel theory that allows an explicit quantification of these requirements is presented. The notion of generation rank of an entity is introduced, and it is proved that the generation process, in most cases, is degenerative in that it strictly and irreversibly decreases the generation rank from parent to descendent. It is also proved that there exists a threshold of rank such that this degeneracy can be avoided if and only if the entity has a generation rank that meets that threshold – this is the von Neumann rank threshold. On the basis of this threshold, an information threshold is derived, which quantifies the minimum amount of information that must be provided to specify an entity such that its descendents are not degenerative. Furthermore, a complexity threshold is obtained, which quantifies the minimum length of the description of that entity in a given language. As an application, self-assembly for a 2 Degrees of Freedom planar robot is considered, and simulation results are presented. A robot arm capable of picking up and placing the components of another arm, in the presence of errors, is considered to have successfully reproduced if these are placed within an allowable tolerance. The example shows that, due to the kinematics of the robot, errors can grow from one generation to the next, until the reproduction process fails eventually. However, error correction (via error sensing and feedback control) can then be used to prevent such degeneracy. The von Neumann generation rank and information thresholds are computed for this example, and are consistent with the simulation results in predicting degeneracy in the case without error correction, and predicting successful self-reproduction in the case with error correction.
The infant mortality conundrum in Uruguay during the first half of the twentieth century: an analysis according to causes of death
Authors: BIRN ANNE-EMANUELLE , CABELLA WANDA , POLLERO RAQUEL 
Published: January 2011

Around 1900 infant mortality rates (IMR) in Uruguay were among the world's lowest. By 1910, however, the IMR began a decades-long stagnation, while other countries experienced ongoing improvements. This article examines the conundrum of Uruguay's infant mortality stagnation, highlighting the leading causes of death – diarrhoeal and respiratory diseases – and their relation to social, economic and political conditions.Drawing on an array of demographic, medical eyewitness and social sources, we explore why, despite Uruguay's precocious social welfare investments, its IMR stagnated and what enabled its eventual decline circa 1940. We conclude that a confluence of public health, medical and social factors enabled disease-specific improvements, but only after political pressure for large-scale redistribution of wealth was translated into extensive welfare state measures.
Expression of enzymes involved in the synthesis of prostaglandin E2 in bovine in vitro-produced embryos
Authors: Saint-Dizier Marie , Grimard Bénédicte , Guyader-Joly Catherine , Humblot Patrice , Ponter Andrew A. 
Published: January 2011

SummaryProstaglandin E2 (PGE2) may play a major role in embryo development and the establishment of pregnancy in cattle. The biosynthesis of PGE2 implies the sequential transformation of arachidonic acid to PGH2 by cyclooxygenases (COXs), then the conversion of PGH2 to PGE2 by prostaglandin E synthases (PGESs). Quantitative RT-PCR was used to examine the expression of COX-1, COX-2, microsomal PGES-1 (mPGES-1), microsomal PGES-2 (mPGES-2) and cytosolic PGES (cPGES) mRNAs in day 7 in vitro-produced (IVP) embryos from oocytes collected by ovum pick-up in Holstein heifers. Transcripts for COX-2 and mPGES-1 were detected in all embryos, whereas transcripts for COX-1 and mPGES-2 were not detected and cPGESs were at the limit of detection in 40% of embryos. Levels of COX-2 and mPGES-1 mRNAs were significantly higher in blastocysts and expanded blastocysts than in morulae and early blastocysts. Furthermore, excellent-quality embryos (grade 1) displayed higher levels of both COX-2 and mPGES-1 than did embryos of good and medium qualities (grades 2–3). Our results suggest that bovine IVP embryos at the morula and blastocyst stages use exclusively the COX-2/mPGES-1 pathway for PGE2 biosynthesis, and that PGE2 is potentially involved in blastocyst expansion and developmental competence.
Partisan Vision Biases Determination of Voter Intent
Authors: Ubel Peter A. , Zikmund-Fisher Brian J. 
Published: January 2011

AbstractIn close, disputed elections, outcomes can depend on determinations of voter intent for ballots that have been filled out improperly. We surveyed 899 adult Minnesotans during a time when the state's U.S. Senate election was still disputed and presented them with ambiguous ballots similar to ballots under dispute in the same election. We randomized participants to three experimental groups, across which we varied the names on the ballot. We found that participants' judgments of voter intent were strongly biased by their voting preferences (p < .002 in all four ballots).