1,721,280 research outputs found
R Code and Output Supporting: Modeling individual variability in habitat selection and movement using integrated step-selection analyses
No full textSee the uploaded readme file.
Update 2025-04-25: Since initial publication, the mixedSSA R package referenced in this DRUM repository has been updated, and we have identified a mistake in one of the equations in the appendix. We have contacted the journal and submitted an erratum, and they have also requested that we update the associated supporting documents. Three files have been added to address this update (Update_delta_method.html, Update_delta_method.R, and helper_functions.R).This repository contains data and R code (along with associated output from running the code) supporting all results reported in: Chatterjee, Nilanjan; Wolfson, David; Kim, Dongmin; Vélez, Juliana; Freeman, Smith; Bacheler, Nathan; Shertzer, Kyle; Taylor, J.; Fieberg, John 2024. Modelling individual variability in habitat selection and movement using integrated step-selection analysis. Methods in Ecology and Evolution. The code demonstrates how to model the individual variation in habitat selection and movement parameters using integrated step-selection analysis.JF and NC were supported by National Aeronautics and Space Administration award 80NSSC21K1182 and JF received partial salary support from the Minnesota Agricultural Experimental Station.Chatterjee, Nilanjan; Wolfson, David; Kim, Dongmin; Velez, Juliana; Freeman, Smith; Bacheler, Nathan; Shertzer, Kyle; Taylor, Chris; Fieberg, John. (2024). R Code and Output Supporting: Modeling individual variability in habitat selection and movement using integrated step-selection analyses. Retrieved from the Data Repository for the University of Minnesota (DRUM), https://doi.org/10.13020/27hq-zx30
Exhumation of the UHP Tso Morari eclogite as a diapir rising through the mantle wedge
No full textUltrahigh-pressure (UHP) rocks such as the coesite-bearing eclogites, occurring as boudins within felsic gneisses of the Tso Morari dome in northwestern Himalayas, originated through subduction of the northern continental margin of India during its early Eocene collision with the Kohistan–Ladakh arc. These rocks are believed to be exhumed through a low-viscosity channel along the top surface of the subducting slab. However, details of the exhumation mechanism are poorly known. We present new constraints on the P–T evolution of hydrous and carbonate-rich samples of the Tso Morari eclogite between 2.2–2.3 GPa/400–425 °C and ~0.4 GPa/450 °C using thermobarometry and calculated P–T– M[subscript CO[subscript 2]] phase equilibria. Our results indicate that the eclogites were strongly heated at high pressures from 400–425 °C at 2.2–2.3 GPa to 670–720 °C at 1.8–1.9 GPa during the early stages of exhumation. Diffusion modeling of Ca variation across the core–rim interface of garnet indicates that the heating stage lasted only <0.1 Myr, in accordance with geochronological constraints and fast exhumation rates. Our P–T path is at odds with exhumation of the eclogites along a subduction channel as model calculations indicate that the intermediate P–T conditions of 1.8–1.9 GPa/670–720 °C are not achieved along the subducting slab. Instead, the constrained P–T conditions are consistent with heating within the mantle wedge overlying the subducting slab. Therefore, we conclude that the Tso Morari eclogites were possibly exhumed as part of a low-density, felsic diapir rising through the mantle wedge. Based on low viscosity values (1.7 × 10[superscript 19]–5.0 × 10[superscript 19] Pa s) of mantle wedges associated with modern subduction zones, the calculated exhumation rate for the Tso Morari eclogite is extremely fast (29–147 mm/yr) and at par with that constrained for other northwestern Himalayan UHP rocks.National Science Foundation (U.S.) (NSF EAR 0910644
Origin of the Powai ankaramite, and the composition, P–T conditions of equilibration and evolution of the primary magmas of the Deccan tholeiites
No full textThe Powai ankaramite flow from Mumbai, western Deccan Traps, contains abundant crystals of augite (En[subscript 59–47]Fs[subscript 10–14]Wo[subscript 27–42], 22–40 modal %, 3–5 mm) and olivine (Fo[subscript 84–74], 11–16 modal %, 1–2 mm), and minor plagioclase (An[subscript 71], ~0.5 mm) embedded in a fine-grained matrix. Minor orthopyroxene (En[subscript 79–77]Fs[subscript 16–19]Wo[subscript 5–4]) with irregular and embayed margins is mantled by thick augite overgrowth rims. The Fe–Mg distribution between the large crystals and bulk rock shows disequilibrium, indicating that the ankaramite is a cumulate rock. The ankaramite probably formed by the intrusion of tholeiitic melt into a cumulate pile with olivine, augite, and orthopyroxene left by the crystallization of earlier magmas, resulting in orthopyroxene dissolution and subsequent precipitation of augite. Olivine-hosted melt inclusions and melts represented by the ankaramite groundmass and some associated tholeiitic dikes are multiply saturated with olivine + plagioclase + clinopyroxene at ≤6 kb according to phase equilibrium constraints. Calculations involving incremental addition of equilibrium phases to these melts and to the common aphyric tholeiites of the voluminous Ambenali and Mahabaleshwar Formations show that their primary magmas (wt% SiO[subscript 2]: 48–50, MgO: 9.8–11.8, and FeO: 7.2–7.9, and Mg# 70–74) last equilibrated with spinel lherzolite at ~8–13 kb (~30–49 km depths) and ~1268–1332 °C, and trace element considerations indicate ≤15 % batch melting of mantle. These tholeiitic primary magmas then underwent olivine gabbro fractionation in upper crustal magma chambers at depths ≤23 km. The minimum depth of equilibration of the primary magmas is shallower than the present-day Moho in the Mumbai area based on seismological data, indicating localized mantle upwelling and lower crustal interactions previously inferred from the Nd–Sr isotopic ratios and other geochemical characteristics of the ankaramite and associated tholeiites
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Multilocus approaches to the detection of disease susceptibility regions: methods and applications
Full text linkThis thesis focuses on multilocus methods designed to detect single nucleotide polymorphisms (SNPs) that are associated with disease using case-control data. I study multilocus methods that allow for interaction in the regression model because epistasis is thought to be pervasive in the etiology of common human diseases. In contrast, the single-SNP models widely used in genome wide association studies (GWAS) are thought to oversimplify the underlying biology. I consider both pairwise interactions between individual SNPs and modular interactions between sets of biologically similar SNPs. Modular epistasis may be more representative of disease processes and its incorporation into regression analyses yields more parsimonious models. My methodological work focuses on strategies to increase power to detect susceptibility SNPs in the presence of genetic interaction. I emphasize the effect of gene-gene independence constraints and explore methods to relax them. I review several existing methods for interaction analyses and present their first empirical evaluation in a GWAS setting. I introduce the innovative retrospective Tukey score test (RTS) that investigates modular epistasis. Simulation studies suggest it offers a more powerful alternative to existing methods. I present diverse applications of these methods, using data from a multi-stage GWAS on prostate cancer (PRCA). My applied work is designed to generate hypotheses about the functionality of established susceptibility regions for PRCA by identifying SNPs that affect disease risk through interactions with them. Comparison of results across methods illustrates the impact of incorporating different forms of epistasis on inference about disease association. The top findings from these analyses are well supported by molecular studies. The results unite several susceptibility regions through overlapping biological pathways known to be disrupted in PRCA, motivating replication study
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Genetic susceptibility to chronic inflammatory intestinal diseases and risk of pancreatic ductal adenocarcinoma: a pathway-based analysis of genome-wide association studies
Full text linkBackground: Chronic inflammation is known to play a role in pancreatic carcinogenesis. Registry-based epidemiologic studies suggest associations between chronic inflammatory intestinal diseases and pancreatic ductal adenocarcinoma (PDAC).
Methods: We examined the association between genomic regions (20 kb upstream and 20 kb downstream) surrounding germline variants for Crohn’s disease, ulcerative colitis, inflammatory bowel disease (Crohn’s disease and ulcerative colitis combined) and celiac disease identified in published genome-wide association studies (GWAS) and PDAC risk in 8384 cases and 11955 controls of European descent using summary statistic GWAS data from the Pancreatic Cancer Cohort Consortium (PanScan) and the Pancreatic Cancer Case Control Consortium (PanC4). We employed the summary adaptive rank truncated product (sARTP) method to test the overall association of the combined genomic regions for each respective disease.
Results: Categorization of the genomic regions for ulcerative colitis, Crohn’s disease, and inflammatory bowel disease were associated with PDAC at P-values < 0.05 (0.0030, 0.037, and 0.0018, respectively). After excluding the regions around the previously identified GWAS loci for PDAC (500 kb upstream and 500 kb downstream), only the inflammatory bowel disease genomic regions remained borderline significantly associated with PDAC (P-value = 0.047). The top genes contributing to the inflammatory bowel disease association after excluding the regions around known PDAC GWAS signals were ACTR2 and LINC00339 (P-value < 0.001). Genomic regions for celiac disease were not associated with PDAC (P-value=0.31).
Conclusions: Our results from a large consortium provide modest support for the hypothesis that genomic regions surrounding germline risk variants for gastrointestinal inflammatory diseases (based on published GWAS loci) are associated with PDAC
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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