Publications by authors named "Kevin Roberts"

Article Synopsis
  • Latin America's genetic diversity offers a unique opportunity to study Alzheimer's disease (AD) and frontotemporal dementia (FTD), with a focus on identifying related genetic variations.
  • The study involved 2,162 participants from six countries who underwent extensive genomic sequencing and analysis to detect genetic factors linked to these dementias.
  • Results highlighted a mix of American, African, and European ancestries, discovered 17 pathogenic variants, and revealed specific genetic variations tied to AD and FTD inheritance patterns in affected families.
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The particulate properties of α-lactose monohydrate (αLMH), an excipient and carrier for pharmaceuticals, is important for the design, formulation and performance of a wide range of drug products. Here an integrated multi-scale workflow provides a detailed molecular and inter-molecular (synthonic) analysis of its crystal morphology, surface chemistry and surface energy. Predicted morphologies are validated in 3D through X-ray diffraction (XCT) contrast tomography.

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Global warming threatens wild bees and their interaction with plants. While earlier studies have highlighted the negative effects of elevated temperatures on bee-plant interactions, we still lack knowledge about how they impact the foraging behaviours that are central to bee pollination activities. To address this knowledge gap, we investigated how ambient temperature affected the foraging behaviours of the bumblebee .

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  • This study focuses on using a morphological approach to measure how quickly facetted crystals grow in a solution, specifically looking at the β-form of l-glutamic acid.
  • The growth rates of various faces of the crystal were determined through image processing and were found to align with previous research using different methods.
  • The research also recorded a transformation in crystal shape from a needle-like appearance to a more tabular form, while providing a new method to estimate changes in solution supersaturation during the growth process.
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  • Azoles, mainly used for treating recurrent vulvovaginal candidiasis (RVVC), have seen a notable increase in non-yeast infections and azole-resistant cases over a three-year study period in Leeds, UK.* -
  • A total of 5461 vaginal samples were analyzed, revealing that while the proportion of traditional yeast infections declined, non-candida yeast (NCAY) infections rose significantly, especially from 2.8% to 6.8% for one specific NCAY species.* -
  • There was a marked increase in fluconazole-resistant strains, making treatment challenging, with a shift in primary care protocols potentially contributing to this rise in resistance and NCAY prevalence.*
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Winter diapause in insects is commonly terminated through cold exposure, which, like vernalization in plants, prevents development before spring arrives. Currently, quantitative understanding of the temperature dependence of diapause termination is limited, likely because diapause phenotypes are generally cryptic to human eyes. We introduce a methodology to tackle this challenge.

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Article Synopsis
  • - The study explores how different solvents affect the crystallization and polymorphic forms of ritonavir, a drug used for treating AIDS, finding that rapid cooling leads to the unstable form I in certain solvents while ethanol favors the stable form II.
  • - Isothermal crystallization experiments indicate that higher solubility in specific solvents reduces the driving force required for nucleation, confirming a consistent pattern with theoretical predictions on solvation behavior.
  • - Molecular dynamics simulations reveal that solvent choice impacts conformational interactions in the solution phase, which may hinder nucleation and interfere with the formation of stable hydrogen bonds necessary for producing form II of the drug.
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In their simulation study, Garcia-Costoya et al. (2023) conclude that evolutionary constraints might aid populations facing climate change. However, we are concerned that this conclusion is largely a consequence of the simulated temperature variation being too small, and, most importantly, that uneven limitations to standing variation disadvantage unconstrained populations.

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Precision measurement of the growth rate of individual single crystal facets () represents an important component in the design of industrial crystallization processes. Current approaches for crystal growth measurement using optical microscopy are labor intensive and prone to error. An automated process using state-of-the-art computer vision and machine learning to segment and measure the crystal images is presented.

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Over the past decades, increasing environmental temperatures have been identified as one of the causes of major insect population declines and biodiversity loss. However, it is unclear how these rising temperatures affect endoheterothermic insects, like bumblebees, that have evolved thermoregulatory capacities to exploit cold and temperate habitats. To investigate this, we measured head, thoracic, and abdominal temperature of bumblebee (Bombus terrestris) workers across a range of temperatures (24 °C-32 °C) during three distinct behaviors.

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Organisms inhabiting highly seasonal environments must cope with a wide range of environmentally induced challenges. Many seasonal challenges require extensive physiological modification to survive. In winter, to survive extreme cold and limited resources, insects commonly enter diapause, which is an endogenously derived dormant state associated with minimized cellular processes and low energetic expenditure.

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Kelp and other habitat-forming seaweeds in the intertidal zone are exposed to a suite of environmental factors, including temperature and hydrodynamic forces, that can influence their growth, survival, and ecological function. Relatively little is known about the interactive effect of temperature and hydrodynamic forces on kelp, especially the effect of cold stress on biomechanical resistance to hydrodynamic forces. We used the intertidal kelp Egregia menziesii to investigate how freezing in air during a low tide changes the kelp's resistance to breaking from hydrodynamic forces.

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Phenotypic plasticity is produced and maintained by processes regulating the transcriptome. While differential gene expression is among the most important of these processes, relatively little is known about other sources of transcriptional variation. Previous work suggests that alternative splicing plays an extensive and functionally unique role in transcriptional plasticity, though plastically spliced genes may be more constrained than the remainder of expressed genes.

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Insects have the capacity to significantly modify their metabolic rate according to environmental conditions and physiological requirement. Consequently, the respiratory patterns can range from continuous gas exchange (CGE) to discontinuous gas exchange (DGE). In the latter, spiracles are kept closed during much of the time, and gas exchange occurs only during short periods when spiracles are opened.

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In seasonal environments, many animals, including insects, enter dormancy, where they are limited to a fixed energy budget. The inability to replenish energetic stores during these periods suggests insects should be constrained by pre-dormancy energy stores. Over the last century, the community of researchers working on survival during dormancy has operated under the strong assumption that energy limitation is a key fitness trait driving the evolution of seasonal strategies.

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Grid-based systematic search methods are used to investigate molecule-molecule, molecule-surface, and surface-surface contributions to interparticle interactions in order to identify the crystal faces that most strongly affect particle behavior during powder blend formulation and delivery processes. The model system comprises terbutaline sulfate (TBS) as an active pharmaceutical ingredient (API) and α-form lactose monohydrate (LMH). A combination of systematic molecular modeling and X-ray computed tomography (XCT) is used to determine not only the adhesive and cohesive interparticle energies but, also the agglomeration behavior during manufacturing and de-agglomeration behavior during delivery after inhalation.

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Detailed atomistic interactions of 1,1,1,2-tetrafluoroethane (HFA-134a) liquid were presented in a data format, namely, DL_ANALYSER Notation for Atomic Interactions (DANAI), that annotates precisely the nature of interactions that is discoverable and searchable without having to resolve to diagrammatic illustrations. The datasets were obtained from raw atomic trajectory files of HFA-134a pure liquid models produced by using DL_POLY molecular dynamics software package. The trajectory datafiles contain expressions of atomic species in a natural chemical sense, and hence, provide localized key interactions, 'at a glance', of the liquid model on otherwise a typically disordered system consists of complex network of intermolecular interactions.

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Predator populations are imperiled globally, due in part to changing habitat and trophic interactions. Theoretical and laboratory studies suggest that heterogeneous landscapes containing prey refuges acting as source habitats can benefit both predator and prey populations, although the importance of heterogeneity in natural systems is uncertain. Here, we tested the hypothesis that landscape heterogeneity mediates predator-prey interactions between the California spotted owl (Strix occidentalis occidentalis)-a mature forest species-and one of its principal prey, the dusky-footed woodrat (Neotoma fuscipes)-a younger forest species-to the benefit of both.

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Article Synopsis
  • The study investigates how different solvents (isopropanol, ethanol, methanol, toluene, and acetonitrile) affect the solubility, crystallizability, and nucleation of tolfenamic acid (TFA) through experimental studies and intermolecular modeling.
  • Isopropanol shows the highest solubility for TFA, with strong solvent-solute interactions leading to greater than ideal solubility, while the crystallizability order varies across solvents, being lowest in isopropanol and highest in acetonitrile.
  • Nucleation occurs progressively in all solvents, with isopropanol exhibiting higher interfacial tension and larger critical nucleus radius, resulting in a lower nucleation rate
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  • Systemic Lupus Erythematosus (SLE) is an autoimmune disease that is more severe in individuals of African American ancestry compared to those of European American ancestry, highlighting the influence of genetics on the disease's clinical course.
  • The research involved analyzing DNA methylation patterns in SLE patients and controls to uncover differences linked to ancestry and the presence of Lupus Nephritis (LN).
  • A total of 51 differentially methylated positions were identified, primarily associated with genes involved in type I interferon signaling, indicating a potential genetic mechanism affecting SLE severity across different ancestries.
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Fine chemicals produced via batch crystallization with properties dependent on the crystal size distribution require precise control of supersaturation, which drives the evolution of crystal size over time. Model predictive control (MPC) of supersaturation using a mechanistic model to represent the behavior of a crystallization process requires less experimental time and resources compared with fully empirical model-based control methods. Experimental characterization of the hexamine-ethanol crystallization system was performed in order to collect the parameters required to build a one-dimensional (1D) population balance model (PBM) in gPROMS FormulatedProducts software (Siemens-PSE Ltd.

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The data presented in this article relates to the crystallisation of 8 single n-alkanes, CH - CH in representative diesel solvents dodecane and toluene, as well as a mixture of these 8-alkanes with a composition representative of real diesel fuel in the same solvents. For the single alkane systems, the data was collected over a range of 5 concentrations ranging from 0.09 - 0.

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The pharmaceutical compound entacapone (()-2-cyano-3-(3,4-dihydroxy-5-nitrophenyl)-,-diethylprop-2-enamide) is important in the treatment of Parkinson's disease, exhibiting interesting polymorphic behavior upon crystallization from solution. It consistently produces its stable form A with a uniform crystal size distribution on the surface of an Au(111) template while concomitantly forming its metastable form D within the same bulk solution. Molecular modeling using empirical atomistic force-fields reveals more complex molecular and intermolecular structures for form D compared to form A, with the crystal chemistry of both polymorphs being dominated by van der Waals and π-π stacking interactions with lower contributions (ca.

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Article Synopsis
  • Many organisms, like montane leaf beetles, enter dormancy during winter to conserve energy and resources by lowering their metabolic rates.
  • Spring emergence from dormancy involves a quick shift in gene expression, where beetles increase digestion and nutrient processing while reducing reliance on stored fats, with females prioritizing reproductive processes earlier than males.
  • Experimental manipulation of snow cover shows that winter conditions significantly influence the timing of these processes, possibly exacerbating the negative impacts of reduced snow cover in mountainous regions like the Sierra Nevada.
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