bluuebunny/crossref_metadata_2025_split huggingface dataset:
Polytene Chromosomal Maps of 11 Drosophila Species: The Order of Genomic Scaffolds Inferred From Genetic and Physical Maps
Authors: Schaeffer Stephen W , Bhutkar Arjun , McAllister Bryant F , Matsuda Muneo , Matzkin Luciano M , O'Grady Patrick M , Rohde Claudia , Valente Vera L S , Aguadé Montserrat , Anderson Wyatt W , Edwards Kevin , Garcia Ana C L , Goodman Josh , Hartigan James , Kataoka Eiko , Lapoint Richard T , Lozovsky Elena R , Machado Carlos A , Noor Mohamed A F , Papaceit Montserrat , Reed Laura K , Richards Stephen , Rieger Tania T , Russo Susan M , Sato Hajime , Segarra Carmen , Smith Douglas R , Smith Temple F , Strelets Victor , Tobari Yoshiko N , Tomimura Yoshihiko , Wasserman Marvin , Watts Thomas , Wilson Robert , Yoshida Kiyohito , Markow Therese A , Gelbart William M , Kaufman Thomas C 
Published: July 2008

AbstractThe sequencing of the 12 genomes of members of the genus Drosophila was taken as an opportunity to reevaluate the genetic and physical maps for 11 of the species, in part to aid in the mapping of assembled scaffolds. Here, we present an overview of the importance of cytogenetic maps to Drosophila biology and to the concepts of chromosomal evolution. Physical and genetic markers were used to anchor the genome assembly scaffolds to the polytene chromosomal maps for each species. In addition, a computational approach was used to anchor smaller scaffolds on the basis of the analysis of syntenic blocks. We present the chromosomal map data from each of the 11 sequenced non-Drosophila melanogaster species as a series of sections. Each section reviews the history of the polytene chromosome maps for each species, presents the new polytene chromosome maps, and anchors the genomic scaffolds to the cytological maps using genetic and physical markers. The mapping data agree with Muller's idea that the majority of Drosophila genes are syntenic. Despite the conservation of genes within homologous chromosome arms across species, the karyotypes of these species have changed through the fusion of chromosomal arms followed by subsequent rearrangement events.
Integration of Cytogenetic and Genetic Linkage Maps Unveils the Physical Architecture of Tomato Chromosome 2
Authors: Koo Dal-Hoe , Jo Sung-Hwan , Bang Jae-Wook , Park Hye-Mi , Lee Sanghyeob , Choi Doil 
Published: July 2008

Abstract
We report the integration of the linkage map of tomato chromosome 2 with a high-density bacterial artificial chromosome fluorescence in situ hybridization (BAC–FISH)-based cytogenetic map. The euchromatic block of chromosome 2 resides between 13 and 142 cM and has a physical length of 48.12 μm, with 1 μm equivalent to 540 kb. BAC–FISH resolved a pair of loci that were 3.7–3.9 Mb apart and were not resolved on the linkage map. Most of the regions had crossover densities close to the mean of ∼200 kb/cM. Relatively hot and cold spots of recombination were unevenly distributed along the chromosome. The distribution of centimorgan/micrometer values was similar to the previously reported recombination nodule distribution along the pachytene chromosome. FISH-based physical maps will play an important role in advanced genomics research for tomato, including map-based cloning of agronomically important traits and whole-genome sequencing.
Complex Network of Wnt Signaling Regulates Neuronal Migrations DuringCaenorhabditis elegansDevelopment
Authors: Zinovyeva Anna Y , Yamamoto Yuko , Sawa Hitoshi , Forrester Wayne C 
Published: July 2008

AbstractMembers of the Wnt family of secreted glycoproteins regulate many developmental processes, including cell migration. We and others have previously shown that the Wnts egl-20, cwn-1, and cwn-2 are required for cell migration and axon guidance. However, the roles in cell migration of all of the Caenorhabditis elegans Wnt genes and their candidate receptors have not been explored fully. We have extended our analysis to include all C. elegans Wnts and six candidate Wnt receptors: four Frizzleds, the sole Ryk family receptor LIN-18, and the Ror receptor tyrosine kinase CAM-1. We show that three of the Wnts, CWN-1, CWN-2, and EGL-20, play major roles in directing cell migrations and that all five Wnts direct specific cell migrations either by acting redundantly or by antagonizing each other's function. We report that all four Frizzleds function to direct Q-descendant cell migrations, but only a subset of the putative Wnt receptors function in directing migrations of other cells. Finally, we find striking differences between the phenotypes of the Wnt quintuple and Frizzled quadruple mutants.
Lentiviral-Mediated HoxB4 Expression in Human Embryonic Stem Cells Initiates Early Hematopoiesis in a Dose-Dependent Manner but Does Not Promote Myeloid Differentiation
Authors: Unger Christian , Kärner Elerin , Treschow Alexandra , Stellan Birgitta , Felldin Ulrika , Concha Hernan , Wendel Mikael , Hovatta Outi , Aints Alar , Ährlund-Richter Lars , Dilber M. Sirac 
Published: July 2008

Abstract
The variation of HoxB4 expression levels might be a key regulatory mechanism in the differentiation of human embryonic stem cell (hESC)-derived hematopoietic stem cells (HSCs). In this study, hESCs ectopically expressing high and low levels of HoxB4 were obtained using lentiviral gene transfer. Quantification throughout differentiation revealed a steady increase in transcription levels from our constructs. The effects of the two expression levels of HoxB4 were compared regarding the differentiation potential into HSCs. High levels of HoxB4 expression correlated to an improved yield of cells expressing CD34, CD38, the stem cell leukemia gene, and vascular epithelium-cadherin. However, no improvement in myeloid cell maturation was observed, as determined by colony formation assays. In contrast, hESCs with low HoxB4 levels did not show any elevated hematopoietic development. In addition, we found that the total population of HoxB4-expressing cells, on both levels, decreased in developing embryoid bodies. Notably, a high HoxB4 expression in hESCs also seemed to interfere with the formation of germ layers after xenografting into immunodeficient mice. These data suggest that HoxB4-induced effects on hESC-derived HSCs are concentration-dependent during in vitro development and reduce proliferation of other cell types in vitro and in vivo. The application of the transcription factor HoxB4 during early hematopoiesis from hESCs might provide new means for regenerative medicine, allowing efficient differentiation and engraftment of genetically modified hESC clones. Our study highlights the importance of HoxB4 dosage and points to the need for experimental systems allowing controlled gene expression.
Disclosure of potential conflicts of interest is found at the end of this article.
An Induction Gene Trap Screen in Neural Stem Cells Reveals an Instructive Function of the Niche and Identifies the Splicing Regulator Sam68 as a Tenascin-C-Regulated Target Gene
Authors: Moritz Sören , Lehmann Stefanie , Faissner Andreas , von Holst Alexander 
Published: July 2008

Abstract
Neural stem cells (NSCs) reside in a niche that abounds in extracellular matrix (ECM) molecules. The ECM glycoprotein tenascin-C (Tnc) that occurs in more than 25 isoforms represents a major constituent of the privileged NSC milieu. To understand its role for NSCs, the induction gene trap technology was successfully applied to mouse embryonic NSCs, and a library of more than 500 NSC lines with independent gene trap vector integrations was established. Our pilot screen identified Sam68 as a target of Tnc signaling in NSCs. The Tnc-mediated downregulation of Sam68, which we found expressed at low levels in the niche along with Tnc, was independently confirmed on the protein level. Sam68 is a multifunctional RNA-binding protein, and its potential significance for cultured NSCs was studied by overexpression. Increased Sam68 levels caused a marked reduction in NSC cell proliferation. In addition, Sam68 is a signal-dependent regulator of alternative splicing, and its overexpression selectively increased the larger Tnc isoforms, whereas a mutated phosphorylation-deficient Sam68 variant did not. This emphasizes the importance of Sam68 for NSC biology and implicates an instructive rather than a purely permissive role for Tnc in the neural stem cell niche.
Disclosure of potential conflicts of interest is found at the end of this article.
Therapeutic Potential of Mesenchymal Stem Cells Producing Interferon-α in a Mouse Melanoma Lung Metastasis Model
Authors: Ren Changchun , Kumar Sanjay , Chanda Diptiman , Chen Jian , Mountz John D. , Ponnazhagan Selvarangan 
Published: July 2008

Abstract
Adult stem cells represent a potential source for cell-based therapy of cancer. The present study evaluated the potential of bone marrow-derived mesenchymal stem cells (MSC), genetically modified to express interferon (IFN)-α, for the treatment of lung metastasis in an immunocompetent mouse model of metastatic melanoma. A recombinant adeno-associated virus (rAAV) 6 vector encoding IFN-α was used to transduce mouse bone marrow-derived MSC ex vivo. Expression and bioactivity of the transgenic protein from rAAV-transduced MSC were confirmed prior to in vivo studies. A lung metastasis model of melanoma was developed by i.v. injection of B16F10 cells into 8-week-old C57BL/6 mice. Ten days later, MSC transduced with rAAV-IFN-α or green fluorescent protein were intravenously injected. One cohort of mice was sacrificed to determine the effects of the therapy at an earlier time point, and another cohort was observed for long-term survival. Results indicated that systemic administration of MSC producing IFN-α reduced the growth of B16F10 melanoma cells and significantly prolonged survival. Immunohistochemistry analysis of the tumors from MSC-IFN-α-treated animals indicated an increase in apoptosis and a decrease in proliferation and blood vasculature. These data demonstrate the potential of adult MSC constitutively producing IFN-α to reduce the growth of lung metastasis in melanoma.
Disclosure of potential conflicts of interest is found at the end of this article.
Neural Induction with Neurogenin1 Increases the Therapeutic Effects of Mesenchymal Stem Cells in the Ischemic Brain
Authors: Kim Sung-Soo , Yoo Seung-Wan , Park Tae-Seok , Ahn Seung-Cheol , Jeong Han-Seong , Kim Ji-Won , Chang Da-Young , Cho Kyung-Gi , Kim Seung U. , Huh Youngbuhm , Lee Jong-Eun , Lee Soo-Yeol , Lee Young-Don , Suh-Kim Haeyoung 
Published: July 2008

Abstract
Mesenchymal stem cells (MSCs) have been shown to ameliorate a variety of neurological dysfunctions. This effect is believed to be mediated by their paracrine functions, since these cells rarely differentiate into neuronal cells. It is of clinical interest whether neural induction of MSCs is beneficial for the replacement therapy of neurological diseases. Here we report that expression of Neurogenin1 (Ngn1), a proneural gene that directs neuronal differentiation of progenitor cells during development, is sufficient to convert the mesodermal cell fate of MSCs into a neuronal one. Ngn1-expressing MSCs expressed neuron-specific proteins, including NeuroD and voltage-gated Ca2+ and Na+ channels that were absent in parental MSCs. Most importantly, transplantation of Ngn1-expressing MSCs in the animal stroke model dramatically improved motor functions compared with the parental MSCs. MSCs with Ngn1 populated the ischemic brain, where they expressed mature neuronal markers, including microtubule associated protein 2, neurofilament 200, and vesicular glutamate transporter 2, and functionally connected to host neurons. MSCs with and without Ngn1 were indistinguishable in reducing the numbers of Iba1+, ED1+ inflammatory cells, and terminal deoxynucleotidyl transferase dUTP nick-end labeling+ apoptotic cells and in increasing the numbers of proliferating Ki67+ cells. The data indicate that in addition to the intrinsic paracrine functions of MSCs, motor dysfunctions were remarkably improved by MSCs able to transdifferentiate into neuronal cells. Thus, neural induction of MSCs is advantageous for the treatment of neurological dysfunctions.
Disclosure of potential conflicts of interest is found at the end of this article.
Chemoattractive Activity of Sonic Hedgehog in the Adult Subventricular Zone Modulates the Number of Neural Precursors Reaching the Olfactory Bulb
Authors: Angot Elodie , Loulier Karine , Nguyen-Ba-Charvet Kim T. , Gadeau Alain-Pierre , Ruat Martial , Traiffort Elisabeth 
Published: July 2008

Abstract
The adult subventricular zone (SVZ) supports neural stem cell self-renewal and differentiation and continually gives rise to new neurons throughout adult life. The mechanisms orienting the migration of neuroblasts from the SVZ to the olfactory bulb (OB) via the rostral migratory stream (RMS) have been extensively studied, but factors controlling neuroblast exit from the SVZ remain poorly explored. The morphogen Sonic Hedgehog (Shh) displays proliferative and survival activities toward neural stem cells and is an axonal chemoattractant implicated in guidance of commissural axons during development. We identify here the presence of Shh protein in SVZ extracts and in the cerebrospinal fluid of adult mice, and we demonstrate that migrating neuroblasts in the SVZ and RMS express the Shh receptor Patched. We show that Shh displays a chemoattractive activity in vitro on SVZ-derived neuronal progenitors, an effect blocked by Cur61414, a Smoothened antagonist. Interestingly, Shh-expressing cells grafted above the RMS of adult mice exert a chemoattractive activity on migrating neuroblasts in vivo, thus inducing their accumulation and deviation from their normal migratory pathway. Furthermore, the adenoviral transfer of Shh into the lateral ventricle or the blocking of Shh present in the SVZ of adult mice using its physiological antagonist Hedgehog interacting protein or neutralizing Shh antibodies provides in vivo evidence that Shh can retain SVZ-derived neuroblasts. The ability to modulate the number of neuroblasts leaving the SVZ and reaching the OB through the chemoattractive activity of Shh suggests a novel degree of plasticity in cell migration of this adult stem cell niche.
Disclosure of potential conflicts of interest is found at the end of this article.
Does subcellular distribution in plants dictate the trophic bioavailability of cadmium to Porcellio dilatatus (crustacea, isopoda)?
Authors: Monteiro Marta S , Santos Conceição , Soares Amadeu M. V. M , Mann Reinier M 
Published: July 2008

Abstract
The present study examined how subcellular partitioning of Cd in plants with different strategies to store and detoxify Cd may affect trophic transfer of Cd to the isopod Porcellio dilatatus. The plant species used were Lactuca sativa, a horticultural metal accumulator species; Thlaspi caerulescens, a herbaceous hyperaccumulator species; and the nonaccumulator, T. arvense. Taking into account that differences in subcellular distribution of Cd in plants might have an important role in the bioavailability of Cd to a consumer, a differential centrifugation technique was adopted to separate plant leaf tissues into four different fractions: cell debris, organelles, heat-denatured proteins, and heat-stable proteins (metallothionein-like proteins). Plants were grown in replicate hydroponic systems and were exposed for 7 d to 100 μM Cd spiked with 109Cd. After a 14-d feeding trial, net assimilation of Cd in isopods following consumption of T. caerulescens and T. arvense leaves reached 16.0 ± 2.33 and 21.9 ± 1.94 μg/g animal, respectively. Cadmium assimilation efficiencies were significantly lower in isopods fed T. caerulescens (10.0 ± 0.92%) than in those fed T. arvense (15.0 ± 1.03%). In further experiments, Cd assimilation efficiencies were determined among isopods provided with purified subcellular fractions of the three plants. On the basis of our results, Cd bound to heat-stable proteins was the least bioavailable to isopods (14.4–19.6%), while Cd bound to heat-denatured proteins was the most trophically available to isopods (34.4–52.8%). Assimilation efficiencies were comparable in isopods fed purified subcellular fractions from different plants, further indicating the importance of subcellular Cd distribution in the assimilation. These results point to the ecological relevance of the subcellular Cd distribution in plants, which directly influence the trophic transfer of Cd to the animal consumer.
Scale for Contraversive Pushing: Cutoff Scores for Diagnosing “Pusher Behavior” and Construct Validity
Authors: Baccini Marco , Paci Matteo , Nannetti Luca , Biricolti Claudia , Rinaldi Lucio A 
Published: July 2008

Background and PurposeConsiderable disagreement exists among researchers with regard to the prevalence, pathophysiology, and treatment of “pusher behavior” (PB), partly because of different testing procedures. This study was primarily aimed at establishing cutoff scores for and the construct validity of the Scale for Contraversive Pushing (SCP). The prevalence of PB in people with right- and left-brain lesions also was investigated.Subjects and MethodsThe study subjects were 105 consecutive patients with recent stroke. Two methods were used to diagnose PB: clinical examination and SCP score with 3 different cutoff points—an SCP total score of greater than 0 (Crit_1), subscores in each section of the scale of greater than 0 (Crit_2), and subscores in each section of the scale of ≥1 (Crit_3). Clinical and SCP diagnoses were independently made by different examiners. The Cohen κ coefficient was used to determine the agreement between clinical and SCP diagnoses. The construct validity of the SCP was estimated by calculation of Spearman rank correlation coefficients for SCP and balance, mobility, and functional scores.ResultsThe agreement between clinical and SCP diagnoses was low (κ=.212) when Crit_1 was used. Crit_2 led to the highest agreement with the clinical diagnosis (κ=.933). However, only Crit_3, although globally less accurate (κ=.754), ensured no false-positive results. The construct validity of the SCP was demonstrated by significant (P&lt;.001) moderate to high correlations with mobility (rho=.595), functional (rho=.632), and balance (rho=.666) scores. The prevalence of PB was not influenced by the side of the lesion. A limitation of the study was that the reliability of the clinical examination method was not investigated.Discussion and ConclusionThe results support the validity of the SCP and suggest the need to choose different SCP cutoff criteria (Crit_2 or Crit_3) according to the aim of the evaluation.
Iron(II) Metallomesogens Exhibiting Coupled Spin State and Liquid Crystal Phase Transitions near Room Temperature
Authors: Seredyuk Maksym , Gaspar Ana B. , Ksenofontov Vadim , Galyametdinov Yury , Kusz Joachim , Gütlich Philipp 
Published: July 2008

AbstractReaction of the ligand 2,2,2‐tris(2‐aza‐3‐((5‐akloxy)(6‐methyl)(2‐pyridyl))prop‐2‐enyl)ethane (Cn‐tameMe) with Fe(X)2 · sH2O salts afforded a series of spin crossover metallomesogens with general formula [Fe(Cn‐tame)](X)2 · sH2O (s ≥ 0), with n = 6, 10, 12, 14, 16, 17, 18, or 20 and X = ClO4− or BF4−. Single crystal X‐ray measurements have been performed on the [Fe(C6‐tameMe)](ClO4)2 (C6‐1) derivative at 100 K. The complex C6‐1 crystallizes in the triclinic system and adopts the Pbca space group. The iron(II) ion is in a distorted octahedral environment shaped by three imine and three pyridine nitrogen atoms of the Cn‐tameMe ligand. The average Fe–Nim and Fe–Npy bond distance is 1.918(2) Å and 2.084(2) Å, respectively, which are characteristic for the Fe(II) ion in the LS state. Neighbor molecules are packed in a head‐to‐head fashion forming a layered microsegregated structure. Ionic layer is composed of cationic spin crossover head‐groups and perchlorate anions, whereas alkyl tails are arranged into a non‐polar hydrocarbon layer. The complex [Fe(C18‐tameMe)](ClO4)2 (C18‐1) and the series [Fe(Cn‐tameMe)](BF4)2 (n = 10, 12, 14, 16, 17, 18, 20) (Cn‐2) series show thermally driven spin crossover and mesomorphism above 300 K. The thermotropic behavior of compounds Cn‐2 depends on the chain length defined by n. A common structural feature among all homologues of the series is a similar layered structure and adoption on melting of a smectic mesophase at ca. 350–375 K. Formation of the mesophase is due to the melting of the alkyl chains rather than a rearrangement of the ionic bilayers composed of polar SCO cations and BF4− or ClO4− anions. This gives rise to a mesophase with molten alkyl chains but with restricted movement through the ionic layer. Compounds Cn‐2 show thermochromic properties, they are dark violet in the LS state (T < 275 K, Cr) and become red in the HS state (T > 275 K, Cr, SX). These bi‐functional materials combine spin state change and mesomorphic behavior in a narrow interval of temperatures, 300–375 K.
Novel Strategies for the Deposition of COOH Functionalized Conducting Copolymer Films and the Assembly of Inorganic Nanoparticles on Conducting Polymer Platforms
Authors: Vaddiraju Sreeram , Seneca Kris , Gleason Karen K. 
Published: July 2008

AbstractA method for the preparation of COOH functionalized conducting copolymer films; toward the ultimate goal of developing resistance‐based sensing platforms, is presented. The method involved vapor phase copolymerization of pyrrole with a monomer containing the COOH functionality, thiophene‐3‐acetic acid (TAA). This copolymerization strategy aided in avoiding the need to employ brittle poly(thiophene‐3‐acetic acid) (PTAA) films in sensing applications. In this strategy, variation in the gas phase feed ratio of pyrrole to TAA allowed for the variation of the composition of the copolymer film and further allowed for the variation of both the conductivity and the amount of COOH functionality in the films. Further, the effect of covalent attachment of silver on the conductivity of the copolymer films is performed and presented. This covalent attachment of silver served the dual purpose of verifying the presence of active COOH groups on the surface, and also allowed for the quantification of the change in conductivity as a result of such attachment. Use of the conjugated ring containing 4‐aminothiophenol as the linker material enhanced the conductivities of the films. In contrast, employing cysteamine to link silver nanoparticles to the copolymer films did not result in any enhancement in the conductivities. An enhancement in the conductivities, ranging from 2 to 1000 times, is observed on covalent attachment of silver nanoparticles to the copolymer films using 4‐aminothiophenol as the linker material. This increase depended on the amount of TAA in the films and increased with increasing concentrations of TAA in the films. These results clearly indicate the use of these copolymer films in resistance‐based sensing. Further, this covalent attachment could be used as a novel strategy to integrate other inorganic nanomaterials on conducting polymer platforms.
Study of downward gas jets into a liquid
Authors: Emami Ahad , Briens Cedric 
Published: July 2008

AbstractGas jet penetration is an important factor in gas distributor design for two‐ and three‐phase reactors. The penetration length of downward nonreacting gas jets was measured in liquid by optical method and for gas jet velocities at subsonic conditions. The effects on jet penetration of nozzle diameter, gas density, gas jet velocity, liquid viscosity, and liquid surface tension were examined. A generalized correlation to predict the penetration depth of downward gas jets was obtained. Also a simple model, using a shell momentum balance and assuming downward gas jet as a downward cone with constant angle, was introduced and validated with experimental data. Bubble size calculated based on gas jet fluctuation frequency and validated by high‐speed videos. © 2008 American Institute of Chemical Engineers AIChE J, 2008