AI-Informed Approaches to Keyword Generation, Text Summarization, and Document Clustering for Improved Resource Discovery

Academic and cultural institutions are grappling with problems of how to organize, label, and search disparate bodies of texts. As aggregators, preservers, and disseminators of substantial repositories of digital texts, research libraries are naturally situated at the heart of these problems. This chapter explores how unsupervised machine learning may be used to capture and simplify the complexity and nuances of text. Traditional approaches to improving discoverability and accessibility of text through metadata and controlled vocabularies have time-tested strengths. As the volume of digital data explodes, the obstacles and limitations of traditional approaches become more pronounced, and machine learning “show(s) the potential to create efficiencies that smooth the path to access, enhancing description and expanding forms of discovery along the way.”1 In light of the need for new approaches to metadata generation to facilitate discovery, the authors look at Doc2Vec and topic modelling with Latent Dirichlet Allocation (LDA) to explore their utility as assistive tools for authors, librarians, and readers. The authors apply the two approaches to a corpus of electronic theses and dissertations (ETDs) completed at Ohio universities and colleges

Holocene evolution of a coastal barrier complex, Pendine Sands.

This study uses a multidisciplinary approach to elucidate the formation and evolution of a large coastal sand barrier complex in South Wales during the Holocene. Foraminifera, pollen, and geophysicale videncei s usedt o interprett he geometry,l ithology and stratigraphicarl elationships between deposits within the back-barrier area. Heavy mineral analysis and XRDA provide information on potential sediment sources. Geophysical surveys show that the western portion of the barrier at Pendine Sands rests on a ridge of Pleistocene glacigenic sediment. This study shows that the barrier formed during the early Holocene (ca. 8,000 to 7,000 years BP) in response to the drowning of the antecedent topography by rapidly rising relative sea-levels; lithostratigraphic and biostratigraphic evidence from cores recovered within the back-barrier area show that the high energy surf zone did not overstep the gravel ridge and rework the fossil cliffline behind the western portion of the barrier. Sediment reworked from glaci-fluvio deposits in Carmarthen Bay was supplied to the prograding dune system by strong westerly and southwesterly winds and longshore drift. Between ca. 6,200 and 5,700 years BP and between ca. 4,500 and 3,500 years BP the barrier underwent two phases of long-term stability. These periods of barrier progradation and stabilisation were punctuated by relatively short phases of erosion, instability and barrier breakdown. Periods of barrier stability were probably triggered by regressive phases in relative sea-level change, which promoted spit development, whereas the intervening instability and breakdown was probably caused by an increase in storm frequency. The response of this system to increased storm activity was primarily controlled by local topographic and sedimentological factors. The ridge beneath the western portion of the barrier prevented the total breakdown and or landward migration of the barrier dunes. Consequently, the back-barrier sediments deposited behind the barrier were preserved whereas the tidal inlet sequencese asto f the gravel ridge were reworked by wave action and tidal scour. Reclamation of the back-barrier area during the 17th and 19th centuries has had a significant effect on the configuration of the coastline at Pendine Sands. The construction of seawall defences stabilised the barrier dunes and promoted rapid accretion along the seaward side of the barrier dunes and at the distal end of the spit. The large expanse of sandflats which are exposed in Carmarthen Bay at low tide, and the frequency of strong westerly and southwesterly winds, were critical factors in the formation and development of the barrier dunes at Pendine Sands. The significance of antecedent topography indicates that the formation and evolution of this particular barrier should not be considered as typical of regional barrier development

Gene expression profiling in whole blood identifies distinct biological pathways associated with obesity

<p>Abstract</p> <p>Background</p> <p>Obesity is reaching epidemic proportions and represents a significant risk factor for cardiovascular disease, diabetes, and cancer.</p> <p>Methods</p> <p>To explore the relationship between increased body mass and gene expression in blood, we conducted whole-genome expression profiling of whole blood from seventeen obese and seventeen well matched lean subjects. Gene expression data was analyzed at the individual gene and pathway level and a preliminary assessment of the predictive value of blood gene expression profiles in obesity was carried out.</p> <p>Results</p> <p>Principal components analysis of whole-blood gene expression data from obese and lean subjects led to efficient separation of the two cohorts. Pathway analysis by gene-set enrichment demonstrated increased transcript levels for genes belonging to the "ribosome", "apoptosis" and "oxidative phosphorylation" pathways in the obese cohort, consistent with an altered metabolic state including increased protein synthesis, enhanced cell death from proinflammatory or lipotoxic stimuli, and increased energy demands. A subset of pathway-specific genes acted as efficient predictors of obese or lean class membership when used in Naive Bayes or logistic regression based classifiers.</p> <p>Conclusion</p> <p>This study provides a comprehensive characterization of the whole blood transcriptome in obesity and demonstrates that the investigation of gene expression profiles from whole blood can inform and illustrate the biological processes related to regulation of body mass. Additionally, the ability of pathway-related gene expression to predict class membership suggests the feasibility of a similar approach for identifying clinically useful blood-based predictors of weight loss success following dietary or surgical interventions.</p

The Fold Illusion: The Origins and Implications of Ogives on Silicic Lavas

Folds on the surfaces of mafic lavas are among the most readily recognized geological structures and are used as first-order criteria for identifying ancient lavas on Earth and other planetary bodies. However, the presence of surface-folds on the surface of silicic lavas is contested in this study and we challenge the widely accepted interpretation that silicic lava surfaces contain folds using examples from the western United States and Sardinia, Italy. We interpret the ridges and troughs on their upper surfaces, typically referred to as ‘ogives’ or ‘pressure ridges’, as fracture-bound structures rather than folds. We report on the absence of large-scale, buckle-style folds and note instead the ubiquitous presence of multiple generations and scales of tensile fractures comparable to crevasses in glaciers and formed in ways similar to already recognized crease structures. We report viscosity data and results of stress analyses that preclude folding (ductile deformation in compression) of the upper surface of silicic lavas at timescales of emplacement (weeks to months). Therefore, analysis of fold geometry (wavelength, amplitude, etc.) is erroneous, and instead the signal produced reflects the strength and thickness of the brittle upper surface stretching over a ductile interior. The presence of ogives on the surfaces of lavas on other planetary bodies may help to elucidate their rheological properties and crustal thicknesses, but relating to their tensile strength, not viscosity

An intron variant of the GLI family zinc finger 3 (GLI3) gene differentiates resistance training-induced muscle fiber hypertrophy in younger men

We examined the association between genotype and resistance training-induced changes (12 wk) in dual x-ray energy absorptiometry (DXA)-derived lean soft tissue mass (LSTM) as well as muscle fiber cross-sectional area (fCSA; vastus lateralis; n = 109; age = 22 ± 2 y, BMI = 24.7 ± 3.1 kg/m2). Over 315 000 genetic polymorphisms were interrogated from muscle using DNA microarrays. First, a targeted investigation was performed where single nucleotide polymorphisms (SNP) identified from a systematic literature review were related to changes in LSTM and fCSA. Next, genome-wide association (GWA) studies were performed to reveal associations between novel SNP targets with pre- to post-training change scores in mean fCSA and LSTM. Our targeted investigation revealed no genotype-by-time interactions for 12 common polymorphisms regarding the change in mean fCSA or change in LSTM. Our first GWA study indicated no SNP were associated with the change in LSTM. However, the second GWA study indicated two SNP exceeded the significance level with the change in mean fCSA (P = 6.9 × 10–7 for rs4675569, 1.7 × 10–6 for rs10263647). While the former target is not annotated (chr2:205936846 (GRCh38.p12)), the latter target (chr7:41971865 (GRCh38.p12)) is an intron variant of the GLI Family Zinc Finger 3 (GLI3) gene. Follow-up analyses indicated fCSA increases were greater in the T/C and C/C GLI3 genotypes than the T/T GLI3 genotype (P \u3c.05). Data from the Auburn cohort also revealed participants with the T/C and C/C genotypes exhibited increases in satellite cell number with training (P \u3c.05), whereas T/T participants did not. Additionally, those with the T/C and C/C genotypes achieved myonuclear addition in response to training (P \u3c.05), whereas the T/T participants did not. In summary, this is the first GWA study to examine how polymorphisms associate with the change in hypertrophy measures following resistance training. Future studies are needed to determine if the GLI3 variant differentiates hypertrophic responses to resistance training given the potential link between this gene and satellite cell physiology

Effects of High-Volume Versus High-Load Resistance Training on Skeletal Muscle Growth and Molecular Adaptations

We evaluated the effects of higher-load (HL) versus (lower-load) higher-volume (HV) resistance training on skeletal muscle hypertrophy, strength, and muscle-level molecular adaptations. Trained men (n = 15, age: 23 ± 3 years; training experience: 7 ± 3 years) performed unilateral lower-body training for 6 weeks (3× weekly), where single legs were randomly assigned to HV and HL paradigms. Vastus lateralis (VL) biopsies were obtained prior to study initiation (PRE) as well as 3 days (POST) and 10 days following the last training bout (POSTPR). Body composition and strength tests were performed at each testing session, and biochemical assays were performed on muscle tissue after study completion. Two-way within-subject repeated measures ANOVAs were performed on most dependent variables, and tracer data were compared using dependent samples t-tests. A significant interaction existed for VL muscle cross-sectional area (assessed via magnetic resonance imaging; interaction p = 0.046), where HV increased this metric from PRE to POST (+3.2%, p = 0.018) whereas HL training did not (−0.1%, p = 0.475). Additionally, HL increased leg extensor strength more so than HV training (interaction p = 0.032; HV \u3c HL at POST and POSTPR, p \u3c 0.025 for each). Six-week integrated non-myofibrillar protein synthesis (iNon-MyoPS) rates were also higher in the HV versus HL condition, while no difference between conditions existed for iMyoPS rates. No interactions existed for other strength, VL morphology variables, or the relative abundances of major muscle proteins. Compared to HL training, 6 weeks of HV training in previously trained men optimizes VL hypertrophy in lieu of enhanced iNon-MyoPS rates, and this warrants future research

Tetrameric Structure of Centromeric Nucleosomes in Interphase Drosophila Cells

Centromeres, the specialized chromatin structures that are responsible for equal segregation of chromosomes at mitosis, are epigenetically maintained by a centromere-specific histone H3 variant (CenH3). However, the mechanistic basis for centromere maintenance is unknown. We investigated biochemical properties of CenH3 nucleosomes from Drosophila melanogaster cells. Cross-linking of CenH3 nucleosomes identifies heterotypic tetramers containing one copy of CenH3, H2A, H2B, and H4 each. Interphase CenH3 particles display a stable association of approximately 120 DNA base pairs. Purified centromeric nucleosomal arrays have typical “beads-on-a-string” appearance by electron microscopy but appear to resist condensation under physiological conditions. Atomic force microscopy reveals that native CenH3-containing nucleosomes are only half as high as canonical octameric nucleosomes are, confirming that the tetrameric structure detected by cross-linking comprises the entire interphase nucleosome particle. This demonstration of stable half-nucleosomes in vivo provides a possible basis for the instability of centromeric nucleosomes that are deposited in euchromatic regions, which might help maintain centromere identity

Holocene evolution of a coastal barrier complex, Pendine Sands.

This study uses a multidisciplinary approach to elucidate the formation and evolution of a large coastal sand barrier complex in South Wales during the Holocene. Foraminifera, pollen, and geophysicale videncei s usedt o interprett he geometry,l ithology and stratigraphicarl elationships between deposits within the back-barrier area. Heavy mineral analysis and XRDA provide information on potential sediment sources. Geophysical surveys show that the western portion of the barrier at Pendine Sands rests on a ridge of Pleistocene glacigenic sediment. This study shows that the barrier formed during the early Holocene (ca. 8,000 to 7,000 years BP) in response to the drowning of the antecedent topography by rapidly rising relative sea-levels; lithostratigraphic and biostratigraphic evidence from cores recovered within the back-barrier area show that the high energy surf zone did not overstep the gravel ridge and rework the fossil cliffline behind the western portion of the barrier. Sediment reworked from glaci-fluvio deposits in Carmarthen Bay was supplied to the prograding dune system by strong westerly and southwesterly winds and longshore drift. Between ca. 6,200 and 5,700 years BP and between ca. 4,500 and 3,500 years BP the barrier underwent two phases of long-term stability. These periods of barrier progradation and stabilisation were punctuated by relatively short phases of erosion, instability and barrier breakdown. Periods of barrier stability were probably triggered by regressive phases in relative sea-level change, which promoted spit development, whereas the intervening instability and breakdown was probably caused by an increase in storm frequency. The response of this system to increased storm activity was primarily controlled by local topographic and sedimentological factors. The ridge beneath the western portion of the barrier prevented the total breakdown and or landward migration of the barrier dunes. Consequently, the back-barrier sediments deposited behind the barrier were preserved whereas the tidal inlet sequencese asto f the gravel ridge were reworked by wave action and tidal scour. Reclamation of the back-barrier area during the 17th and 19th centuries has had a significant effect on the configuration of the coastline at Pendine Sands. The construction of seawall defences stabilised the barrier dunes and promoted rapid accretion along the seaward side of the barrier dunes and at the distal end of the spit. The large expanse of sandflats which are exposed in Carmarthen Bay at low tide, and the frequency of strong westerly and southwesterly winds, were critical factors in the formation and development of the barrier dunes at Pendine Sands. The significance of antecedent topography indicates that the formation and evolution of this particular barrier should not be considered as typical of regional barrier development

Children &amp; Climate Change Vulnerability Indices: A Scoping Review Protocol

Study protocol for a scoping review summarizing what climate change vulnerability indices looking at the impact on child health, specifically, have been reported in the current scientific literature