bluuebunny/crossref_metadata_2025_split huggingface dataset:
T2-Weighted 4D Magnetic Resonance Imaging for Application in Magnetic Resonance–Guided Radiotherapy Treatment Planning
Authors: Freedman Joshua N. , Collins David J. , Bainbridge Hannah , Rank Christopher M. , Nill Simeon , Kachelrieß Marc , Oelfke Uwe , Leach Martin O. , Wetscherek Andreas 
Published: April 2017

Objectives
The aim of this study was to develop and verify a method to obtain good temporal resolution T2-weighted 4-dimensional (4D-T2w) magnetic resonance imaging (MRI) by using motion information from T1-weighted 4D (4D-T1w) MRI, to support treatment planning in MR-guided radiotherapy.

Materials and Methods
Ten patients with primary non–small cell lung cancer were scanned at 1.5 T axially with a volumetric T2-weighted turbo spin echo sequence gated to exhalation and a volumetric T1-weighted stack-of-stars spoiled gradient echo sequence with golden angle spacing acquired in free breathing. From the latter, 20 respiratory phases were reconstructed using the recently developed 4D joint MoCo-HDTV algorithm based on the self-gating signal obtained from the k-space center. Motion vector fields describing the respiratory cycle were obtained by deformable image registration between the respiratory phases and projected onto the T2-weighted image volume. The resulting 4D-T2w volumes were verified against the 4D-T1w volumes: an edge-detection method was used to measure the diaphragm positions; the locations of anatomical landmarks delineated by a radiation oncologist were compared and normalized mutual information was calculated to evaluate volumetric image similarity.

Results
High-resolution 4D-T2w MRI was obtained. Respiratory motion was preserved on calculated 4D-T2w MRI, with median diaphragm positions being consistent with less than 6.6 mm (2 voxels) for all patients and less than 3.3 mm (1 voxel) for 9 of 10 patients. Geometrical positions were coherent between 4D-T1w and 4D-T2w MRI as Euclidean distances between all corresponding anatomical landmarks agreed to within 7.6 mm (Euclidean distance of 2 voxels) and were below 3.8 mm (Euclidean distance of 1 voxel) for 355 of 470 pairs of anatomical landmarks. Volumetric image similarity was commensurate between 4D-T1w and 4D-T2w MRI, as mean percentage differences in normalized mutual information (calculated over all respiratory phases and patients), between corresponding respiratory phases of 4D-T1w and 4D-T2w MRI and the tie-phase of 4D-T1w and 3-dimensional T2w MRI, were consistent to 0.41% ± 0.37%. Four-dimensional T2w MRI displayed tumor extent, structure, and position more clearly than corresponding 4D-T1w MRI, especially when mobile tumor sites were adjacent to organs at risk.

Conclusions
A methodology to obtain 4D-T2w MRI that retrospectively applies the motion information from 4D-T1w MRI to 3-dimensional T2w MRI was developed and verified. Four-dimensional T2w MRI can assist clinicians in delineating mobile lesions that are difficult to define on 4D-T1w MRI, because of poor tumor-tissue contrast.
Shortwave Infrared Fluorescence Imaging with the Clinically Approved Near-Infrared Dye Indocyanine Green
Authors: Carr Jessica A. , Franke Daniel , Caram Justin R. , Perkinson Collin F. , Askoxylakis Vasileios , Datta Meenal , Fukumura Dai , Jain Rakesh K. , Bawendi Moungi G. , Bruns Oliver T. 
Published: April 2017

AbstractFluorescence imaging is a method of real-time molecular trackingin vivothat has enabled many clinical technologies. Imaging in the shortwave infrared region (SWIR, 1-2 μm) promises higher contrast, sensitivity, and penetration depths compared to conventional visible and near-infrared (NIR) fluorescence imaging. However, adoption of SWIR imaging in clinical settings has been limited, due in part to the absence of FDA-approved fluorophores with peak emission in the SWIR. Here, we show that commercially available NIR dyes, including the FDA-approved contrast agent indocyanine green (ICG), exhibit optical properties suitable forin vivoSWIR fluorescence imaging. Despite the fact that their emission reaches a maximum in the NIR, these dyes can be imaged non-invasivelyin vivoin the SWIR spectral region, even beyond 1500 nm. We demonstrate real-time fluorescence angiography at wavelengths beyond 1300 nm using ICG at clinically relevant doses. Furthermore, we show tumortargeted SWIR imaging with trastuzumab labeled with IRDye 800CW, a NIR dye currently being tested in multiple phase II clinical trials. Our findings suggest that high-contrast SWIR fluorescence imaging can be implemented alongside existing imaging modalities by switching the detection of conventional NIR fluorescence systems from silicon-based NIR cameras to emerging indium gallium arsenide (InGaAs) SWIR cameras. Using ICG in particular opens the possibility of translating SWIR fluorescence imaging to human clinical applications.
A biological source of marine sedimentary iron oxides
Authors: Beam Jacob P. , Scott Jarrod J. , McAllister Sean M. , Chan Clara S. , McManus James , Meysman Filip J. R. , Emerson David 
Published: April 2017

AbstractThe biogeochemical cycle of iron is intricately linked to numerous element cycles. Although reductive biological processes that bridge the iron cycle to other element cycles are established, little is known about microbial oxidative processes on iron cycling in sedimentary environments—resulting in the formation of iron oxides. Here, we show that a major source of sedimentary iron oxides originates from the metabolic activity of iron-oxidizing bacteria from the class Zetaproteobacteria, stimulated by burrowing animals in coastal sediments. Zetaproteobacteria were estimated to be a global total of 1026cells in coastal, bioturbated sediments and would equate to an annual production of approximately 7.9 x 1015grams of sedimentary iron oxides—twenty-five times larger than the annual flux of iron oxides by rivers. These data suggest that iron-oxidizing Zetaproteobacteria are keystone organisms in marine sedimentary environments given their low numerical abundance; yet exert a profound impact via the production of iron oxides.
Meffil: efficient normalisation and analysis of very large DNA methylation samples
Authors: Min Josine , Hemani Gibran , Smith George Davey , Relton Caroline , Suderman Matthew 
Published: April 2017

AbstractBackgroundTechnological advances in high throughput DNA methylation microarrays have allowed dramatic growth of a new branch of epigenetic epidemiology. DNA methylation datasets are growing ever larger in terms of the number of samples profiled, the extent of genome coverage, and the number of studies being meta-analysed. Novel computational solutions are required to efficiently handle these data.MethodsWe have developedmeffil, an R package designed to quality control, normalize and perform epigenome-wide association studies (EWAS) efficiently on large samples of Illumina Infinium HumanMethylation450 and MethylationEPIC BeadChip microarrays. We testedmeffilby applying it to 6000 450k microarrays generated from blood collected for two different datasets, Accessible Resource for Integrative Epigenomic Studies (ARIES) and The Genetics of Overweight Young Adults (GOYA) study.ResultsA complete reimplementation of functional normalization minimizes computational memory requirements to 5% of that required by other R packages, without increasing running time. Incorporating fixed and random effects alongside functional normalization, and automated estimation of functional normalisation parameters reduces technical variation in DNA methylation levels, thus reducing false positive associations and improving power. We also demonstrate that the ability to normalize datasets distributed across physically different locations without sharing any biologically-based individual-level data may reduce heterogeneity in meta-analyses of epigenome-wide association studies. However, we show that when batch is perfectly confounded with cases and controls functional normalization is unable to prevent spurious associations.Conclusionsmeffilis available online (https://github.com/perishky/meffil/) along with tutorials covering typical use cases.
Single-cell analysis of clonal dynamics in direct lineage reprogramming: a combinatorial indexing method for lineage tracing
Authors: Biddy Brent A. , Waye Sarah E. , Sun Tao , Morris Samantha A. 
Published: April 2017

SummarySingle-cell technologies are offering unprecedented insight into complex biology, revealing the behavior of rare cell populations that are typically masked in bulk population analyses. The application of these methodologies to cell fate reprogramming holds particular promise as the manipulation of cell identity is typically inefficient, generating heterogeneous cell populations. One current limitation of single-cell approaches is that lineage relationships are lost as a result of cell processing, restricting interpretations of the data collected. Here, we present a single-cell resolution lineage-tracing approach based on the combinatorial indexing of cells, ‘CellTagging’. Application of this method, in concert with high-throughput single-cell RNA-sequencing, reveals the transcriptional dynamics of direct reprogramming from fibroblasts to induced endoderm progenitors. These analyses demonstrate that while many cells initiate reprogramming, complete silencing of fibroblast identity and transition to a progenitor-like state represents a rare event. Clonal analyses uncover a remarkable degree of heterogeneity arising from individual cells. Overall, very few cells fully reprogram to generate expanded populations with a low degree of clonal diversity. Extended culture of these engineered cells reveals an instability of the reprogrammed state and reversion to a fibroblast-like phenotype. Together, these results demonstrate the utility of our lineage-tracing approach to reveal dynamics of lineage reprogramming, and will be of broad utility in many cell biological applications.
Bacterial biofilm formation on soil fungi: a widespread ability under controls
Authors: Guennoc Cora Miquel , Rose Christophe , Labbé Jessy , Deveau Aurélie 
Published: April 2017

AbstractIn natural environments, bacteria preferentially live in biofilms that they build on abiotic surfaces but also on living tissues. Although fungi form extensive networks of hyphae within soils and thus could provide immense surfaces for bacteria to build biofilms and to proliferate, the extent on such phenomenon and the consequences for the fitness of both microorganisms is poorly known in soils. Here, we analyzed the process of formation of biofilms by various bacteria on hyphae of soil fungi in anin vitrosetting using confocal and electron microscopy. We showed that the ability to form biofilms on fungal hyphae is widely shared among soil bacteria. In contrast, some fungi, mainly belonging to the Ascomycete class, did not allow for the formation of bacterial biofilms on their surfaces. The formation of biofilms was also strongly modulated by the presence of tree roots and by the development of the ectomycorrhizal symbiosis, suggesting that biofilm formation does not occur randomly in soil but that it is highly regulated by several biotic factors. Finally, our study led to the unexpected finding that networks of filaments made of extracellular DNA were used to build the skeleton of biofilms by a large array of bacteria.
Rapid whole brain imaging of neural activity in freely behaving larval zebrafish (Danio rerio)
Authors: Cong Lin , Wang Zeguan , Chai Yuming , Hang Wei , Shang Chunfeng , Yang Wenbin , Bai Lu , Du Jiulin , Wang Kai , Wen Quan 
Published: April 2017

AbstractThe internal brain dynamics that link sensation and action are arguably better studied during natural animal behaviors. Here we report on a novel volume imaging and 3D tracking technique that monitors whole brain neural activity in freely swimming larval zebrafish (Danio rerio). We demonstrated the capability of our system through functional imaging of neural activity during visually evoked and prey capture behaviors in larval zebrafish.
Altered expression of a unique set of genes reveals complex etiology of Schizophrenia
Authors: Kumar Ashutosh , Singh Himanshu Narayan , Pareek Vikas , Raza Khursheed , Kumar Pavan , Faiq Muneeb A. , Mochan Sankat , Dantham Subrahamanyam , Upadhyaya Ashish Datt 
Published: April 2017

AbstractPurposeThe etiology of schizophrenia is extensively debated, and multiple factors have been contended to be involved. A panoramic view of the contributing factors in a genome-wide study can be an effective strategy to provide a comprehensive understanding of its causality.Materials and MethodsGSE53987 dataset downloaded from GEO-database, which comprised mRNA expression data of post-mortem brain tissue across three regions from control and age-matched subjects of schizophrenia (N= Hippocampus (HIP): C-15, T-18, Prefrontal cortex (PFC): C-15, T-19, Associative striatum (STR): C-18, T-18). Bio-conductor-affy-package used to compute mRNA expression, and further t-test applied to investigate differential gene expression. The analysis of the derived genes performed using PANTHER Classification System and NCBI database.ResultsA set of 40 genes showed significantly altered (p<0.01) expression across all three brain regions. The analyses unraveled genes implicated in biological processes and events, and molecular pathways relating basic neuronal functions.ConclusionsThe deviant expression of genes maintaining basic cell machinery explains compromised neuronal processing in SCZ.AbbreviationsSchizophrenia (SCZ), Hippocampus (HIP), Associative striatum (STR), Prefrontal cortex (PFC)
Fast and simple analysis of MiSeq amplicon sequencing data with MetaAmp
Authors: Dong Xiaoli , Kleiner Manuel , Sharp Christine E. , Thorson Erin , Li Carmen , Liu Dan , Strous Marc 
Published: April 2017

AbstractMicrobial community profiling by barcoded 16S rRNA gene amplicon sequencing currently has many applications in microbial ecology. The low costs of the parallel sequencing of multiplexed samples, combined with the relative ease of data processing and interpretation (compared to shotgun metagenomes) have made this an entry-level approach. Here we present the MetaAmp pipeline for processing of SSU rRNA gene and other non-coding or protein-coding amplicon sequencing data by investigators that are inexperienced with bioinformatics procedures. It accepts single-end or paired-end sequences in fasta or fastq format from various sequencing platforms. It includes read quality control, and merging of forward and reverse reads of paired-end reads. It makes use of UPARSE, Mothur, and the SILVA database for clustering, removal of chimeric reads, taxonomic classification and generation of diversity metrics. The pipeline has been validated with a mock community of known composition. MetaAmp provides a convenient web interface as well as command line interface. It is freely available at:http://ebg.ucalgary.ca/metaamp. Since its launch two years ago, MetaAmp has been used >2,800 times, by many users worldwide.
Genomic and chromatin features shaping meiotic double-strand break formation and repair in mice
Authors: Yamada Shintaro , Kim Seoyoung , Tischfield Sam E. , Lange Julian , Jasin Maria , Keeney Scott 
Published: April 2017

AbstractThe SPO11-generated DNA double-strand breaks (DSBs) that initiate meiotic recombination occur non-randomly across genomes, but mechanisms shaping their distribution and repair remain incompletely understood. Here, we expand on recent studies of nucleotide-resolution DSB maps in mouse spermatocytes. We find that trimethylation of histone H3 lysine 36 around DSB hotspots is highly correlated, both spatially and quantitatively, with trimethylation of H3 lysine 4, consistent with coordinated formation and action of both PRDM9-dependent histone modifications. In contrast, the DSB-responsive kinase ATM contributes independently of PRDM9 to controlling hotspot activity, and combined action of ATM and PRDM9 can explain nearly two-thirds of the variation in DSB frequency between hotspots. DSBs were modestly underrepresented in most repetitive sequences such as segmental duplications and transposons. Nonetheless, numerous DSBs form within repetitive sequences in each meiosis and some classes of repeats are preferentially targeted. Implications of these findings are discussed for evolution of PRDM9 and its role in hybrid strain sterility in mice. Finally, we document the relationship between mouse strain-specific DNA sequence variants within PRDM9 recognition motifs and attendant differences in recombination outcomes. Our results provide further insights into the complex web of factors that influence meiotic recombination patterns.
PHRED-1 is a divergent neurexin-1 homolog that organizes muscle fibers and patterns organs during regeneration
Authors: Adler Carolyn E. , Alvarado Alejandro Sánchez 
Published: April 2017

AbstractRegeneration of body parts requires the replacement of multiple cell types. To dissect this complex process, we utilized planarian flatworms that are capable of regenerating any tissue after amputation. An RNAi screen for genes involved in regeneration of the pharynx identified a novel gene, Pharynx regeneration defective-1 (PHRED-1) as essential for normal pharynx regeneration. PHRED-1 is a predicted transmembrane protein containing EGF, Laminin G, and WD40 domains, is expressed in muscle, and has predicted homologs restricted to other lophotrochozoan species. Knockdown of PHRED-1 causes abnormal regeneration of muscle fibers in both the pharynx and body wall muscle. In addition to defects in muscle regeneration, knockdown of PHRED-1 or the bHLH transcription factor MyoD also causes defects in muscle and intestinal regeneration. Together, our data demonstrate that muscle plays a key role in restoring the structural integrity of closely associated organs, and in planarians it may form a scaffold that facilitates normal intestinal branching.Graphical AbstractHighlights-PHRED-1 is a predicted transmembrane protein that contains Laminin G, EGF and WD40 domains-PHRED-1 is required for normal muscle patterning during regeneration-phred-1is expressed in muscle cells-Muscle forms an essential scaffold for regeneration
How convincing is a matching Y-chromosome profile?
Authors: Andersen Mikkel M , Balding David J 
Published: April 2017

AbstractThe introduction of forensic autosomal DNA profiles was controversial, but the problems were successfully addressed, and DNA profiling has gone on to revolutionise forensic science. Y-chromosome profiles are valuable when there is a mixture of male-source and female-source DNA, and interest centres on the identity of the male source(s) of the DNA. The problem of evaluating evidential weight is even more challenging for Y profiles than for autosomal profiles. Numerous approaches have been proposed, but they fail to deal adequately with the fact that men with matching Y-profiles are re-lated in extended patrilineal clans, many of which may not be represented in available databases. This problem has been exacerbated by recent profiling kits with high mutation rates. Because the relevant population is difficult to define, yet the number of matching relatives is fixed as population size varies, it is typically infeasible to derive population-based match probabilities relevant to a specific crime. We propose a conceptually simple solution, based on a simulation model and software to approximate the distribution of the number of males with a matching Y profile. We show that this distribution is robust to different values for the variance in reproductive success and the population growth rate. We also use importance sampling reweighting to derive the distribution of the number of matching males conditional on a database frequency, finding that this conditioning typically has only a modest impact. We illustrate the use of our approach to quantify the value of Y profile evidence for a court in a way that is both scientifically valid and easily comprehensible by a judge or juror.
High-resolution mapping of heteroduplex DNA formed during UV-induced and spontaneous mitotic recombination events in yeast
Authors: Yin Yi , Dominska Margaret , Yim Eunice , Petes Thomas D. 
Published: April 2017

AbstractDouble-stranded DNA breaks (DSBs) can be generated by both endogenous and exogenous agents. In diploid yeast strains, such breaks are usually repaired by homologous recombination (HR), and a number of different HR pathways have been described. An early step for all HR pathways is formation of a heteroduplex, in which a single-strand from the broken DNA molecule pairs with a strand derived from an intact DNA molecule. If the two strands of DNA are not identical, within the heteroduplex DNA (hetDNA), there will be mismatches. In a wild-type strain, these mismatches are removed by the mismatch repair (MMR) system. In strains lacking MMR, the mismatches persist and can be detected by a variety of genetic and physical techniques. Most previous studies involving hetDNA formed during mitotic recombination have been restricted to a single locus with DSBs induced at a defined position by a site-specific endonuclease. In addition, in most of these studies, recombination between repeated genes was examined; in such studies, the sequence homologies were usually less than 5 kb. In the present study, we present a global mapping of hetDNA formed in a UV-treated MMR-defectivemlh1strain. Although about two-thirds of the recombination events were associated with hetDNA with a continuous array of unrepaired mismatches, in about one-third of the events, we found regions of unrepaired mismatches flanking regions without mismatches. We suggest that these discontinuous hetDNAs involve template switching during repair synthesis, repair of a double-stranded DNA gap, and/or Mlh1-independent MMR. Many of our observed events are not explicable by the simplest form of the double-strand break repair (DSBR) model of recombination. We also studied hetDNA associated with spontaneous recombination events selected on chromosomes IV and V in a wild-type strain. The interval on chromosome IV contained a hotspot for spontaneous crossovers generated by an inverted pair of transposable elements (HS4). We showed that HS4-induced recombination events are associated with the formation of very large (>30 kb) double-stranded DNA gaps.