Publications by authors named "Bentz B"

Diapause regulates seasonal insect life cycles and may be highly variable within and among populations due to genetic and environmental variability. Both types of variation may influence how populations respond plastically or evolutionarily to changing climates. We assessed diapause variability in spruce beetle Dendroctonus rufipennis Kirby (Coleoptera: Curculionidae, Scolytinae), a major forest pest whose life cycle timing is regulated by both prepupal and adult diapauses.

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Insects live in a wide range of thermal environments and have evolved species- and location-specific physiological processes for survival in hot and cold extremes. Thermally driven dormancy strategies, development rates and thresholds are important for synchronizing cohorts within a population and to local climates and often vary among populations within a species. Mountain pine beetle (MPB), Dendroctonus ponderosae Hopkins (Coleoptera: Curculionidae, Scolytinae), is a widely distributed forest insect native to North America with clinal genetic differentiation in thermally dependent traits.

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Identifying dormancy traits is important for predicting insect population success, particularly in a changing climate that could disrupt evolved traits. The mountain pine beetle (Dendroctonus ponderosae Hopkins) is native to North America, is responsible for millions of acres of tree mortality, and is expanding northward in Canada. Research has identified thermal traits important to epidemic-phase ecology that vary among populations.

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Insects have major impacts on forest ecosystems, from herbivory and soil-nutrient cycling to killing trees at a large scale. Forest insects from temperate, tropical, and subtropical regions have evolved strategies to respond to seasonality; for example, by entering diapause, to mitigate adversity and to synchronize lifecycles with favorable periods. Here, we show that distinct functional groups of forest insects; that is, canopy dwellers, trunk-associated species, and soil/litter-inhabiting insects, express a variety of diapause strategies, but do not show systematic differences in diapause strategy depending on functional group.

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Article Synopsis
  • The study characterizes atmospheric aerosol analogs in a lab setting, focusing on how varying concentrations of NaCl in these aerosols affect their optical properties.
  • Light interactions with these aerosols lead to scattering and absorption, which can be analyzed using Mie theory and depend on droplet size and composition.
  • Experiments reveal that altering the NaCl concentration significantly influences both the physical and optical features of the aerosols, allowing for potential adjustments to their properties.
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Fogs, low lying clouds, and other highly scattering environments pose a challenge for many commercial and national security sensing systems. Current autonomous systems rely on optical sensors for navigation whose performance is degraded by highly scattering environments. In our previous simulation work, we have shown that polarized light can penetrate through a scattering environment such as fog.

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Introduction: Male breast cancer is rare and frequently diagnosed at later stages of disease with low survival rates. There is a lack of knowledge of how breast cancer impacts men's occupations.

Objectives: This study is aimed at understanding the lived experiences of men with breast cancer and their changes in occupation.

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Article Synopsis
  • Developed a predictive model for mountain pine beetle oviposition by integrating variations in oviposition rate and fecundity, along with a new method to assess time delay before oviposition.
  • The model utilizes hourly phloem temperature and adult MPB attack data to estimate the probability of oviposition during the MPB season.
  • An asymptotic approximation of the oviposition model was created for easier computation, and both the detailed model and its approximation were compared to existing models, evaluating their predictive effectiveness against previous observations.
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Plants resist herbivores and pathogens by using constitutive (baseline) and inducible (change in defense after an attack) defenses. Inducibility has long been predicted to trade off with constitutive defense, reflecting the economic use of resources. However, empirical evidence for such tradeoffs is variable, and we still lack understanding about when and where defense trade-offs occur.

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A computationally efficient radiative transport model is presented that predicts a camera measurement and accounts for the light reflected and blocked by an object in a scattering medium. The model is in good agreement with experimental data acquired at the Sandia National Laboratory Fog Chamber Facility (SNLFC). The model is applicable in computational imaging to detect, localize, and image objects hidden in scattering media.

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Article Synopsis
  • Climate warming has harmed forest health in the western U.S., particularly for ponderosa pine trees, as evidenced by increased drought-related mortality rates during the 2012-2015 California drought.
  • Researchers observed that over five decades, tree growth and carbon isotope patterns showed heightened sensitivity to drought indicators, suggesting these patterns may serve as early warning signs for potential forest mortality.
  • Management strategies like thinning trees or controlled burns may alleviate competition for water and reduce bark beetle infestations, which could help forests become more resilient to drought stress and mitigate future mortality risks.
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A key component in understanding plant-insect interactions is the nature of host defenses. Research on defense traits among Pinus species has focused on specialized metabolites and axial resin ducts, but the role of lignin in defense within diverse systems is unclear. We investigated lignin levels in the outer bark and phloem of P.

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Random scattering and absorption of light by tiny particles in aerosols, like fog, reduce situational awareness and cause unacceptable down-time for critical systems or operations. Computationally efficient light transport models are desired for computational imaging to improve remote sensing capabilities in degraded optical environments. To this end, we have developed a model based on a weak angular dependence approximation to the Boltzmann or radiative transfer equation that appears to be applicable in both the moderate and highly scattering regimes, thereby covering the applicability domain of both the small angle and diffusion approximations.

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Background: Multiple registries have reported that >40% of high-risk atrial fibrillation patients are not taking oral anticoagulants. The purpose of our study was to determine the presence or absence of active atrial fibrillation and CHADS-VASc (Congestive heart failure, Hypertension, Age ≥75 y, Diabetes mellitus, prior Stroke [or transient ischemic attack or thromboembolism], Vascular disease, Age 65-74 y, Sex category) risk factors to accurately identify high-risk atrial fibrillation (CHADS-VASc ≥2) patients requiring oral anticoagulants and the magnitude of the anticoagulant treatment gap.

Methods: We retrospectively adjudicated 6514 patients with atrial fibrillation documented by at least one of: billing diagnosis, electronic medical record encounter diagnosis, electronic medical record problem list, or electrocardiogram interpretation.

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Forests in the western United States are being subject to more frequent and severe drought events as the climate warms. The 2012-2015 California drought is a recent example, whereby drought stress was exacerbated by a landscape-scale outbreak of western pine beetle (Dendroctonus brevicomis) and resulted in widespread mortality of dominant canopy species including ponderosa pine (Pinus ponderosa). In this study, we compared pairs of large surviving and beetle-killed ponderosa pines following the California drought in the southern Sierra Nevadas to evaluate physiological characteristics related to survival.

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Article Synopsis
  • - The text discusses the ecological impacts of wildland fires, particularly focusing on how they affect tree mortality, which is important because trees support various biological services.
  • - Researchers created the Fire and Tree Mortality (FTM) database that includes detailed records from over 164,000 individual trees affected by prescribed fires and wildfires in the U.S. between 1981 and 2016.
  • - This database serves as a tool for assessing fire mortality models, improving pre- and post-fire decision-making, and identifying areas where further research is needed regarding fire-induced tree death.
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Imaging fluorescence through millimeters or centimeters of tissue has important in vivo applications, such as guiding surgery and studying the brain. Often, the important information is the location of one of more optical reporters, rather than the specifics of the local geometry, motivating the need for a localization method that provides this information. We present an optimization approach based on a diffusion model for the fast localization of fluorescent inhomogeneities in deep tissue with expanded beam illumination that simplifies the experiment and the reconstruction.

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A super-resolution optical imaging method is presented that relies on the distinct temporal information associated with each fluorescent optical reporter to determine its spatial position to high precision with measurements of heavily scattered light. This multiple-emitter localization approach uses a diffusion equation forward model in a cost function, and has the potential to achieve micron-scale spatial resolution through centimeters of tissue. Utilizing some degree of temporal separation for the reporter emissions, position and emission strength are determined using a computationally efficient time stripping multiresolution algorithm.

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The preference-performance hypothesis states that ovipositing phytophagous insects will select host plants that are well-suited for their offspring and avoid host plants that do not support offspring performance (survival, development and fitness). The mountain pine beetle (Dendroctonus ponderosae), a native insect herbivore in western North America, can successfully attack and reproduce in most species of Pinus throughout its native range. However, mountain pine beetles avoid attacking Great Basin bristlecone pine (Pinus longaeva), despite recent climate-driven increases in mountain pine beetle populations at the high elevations where Great Basin bristlecone pine grows.

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Dormancy strategies, including diapause and quiescence, enable insects to evade adverse conditions and ensure seasonally appropriate life stages. A mechanistic understanding of a species' dormancy is necessary to predict population response in a changing climate. Climate change is influencing distribution patterns and population success of many species, including Dendroctonus ponderosae Hopkins (Coleoptera: Curculionidae: Scolytinae), the most important mortality agent of pines in western North America.

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Genome evolution is predicted to be rapid following the establishment of new (neo) sex chromosomes, but it is not known if neo-sex chromosome evolution plays an important role in speciation. Here we combine extensive crossing experiments with population and functional genomic data to examine neo-XY chromosome evolution and incipient speciation in the mountain pine beetle. We find a broad continuum of intrinsic incompatibilities in hybrid males that increase in strength with geographic distance between reproductively isolated populations.

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Chromosomal rearrangement can be an important mechanism driving population differentiation and incipient speciation. In the mountain pine beetle (MPB, Dendroctonus ponderosae), deletions on the Y chromosome that are polymorphic among populations are associated with reproductive incompatibility. Here, we used RAD sequencing across the entire MPB range in western North America to reveal the extent of the phylogeographic differences between Y haplotypes compared to autosomal and X-linked loci.

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We summarize the status of semiochemical-based management of the major bark beetle species in western North America. The conifer forests of this region have a long history of profound impacts by phloem-feeding bark beetles, and species such as the mountain pine beetle (Dendroctonus ponderosae) and the spruce beetle (D. rufipennis) have recently undergone epic outbreaks linked to changing climate.

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Diffuse optical imaging through centimeters of tissue has emerged as a powerful tool in biomedical research. However, applications in the operating theater have been limited in part due to data set requirements and computational burden. We present an approach that uses a small number of optical source-detector pairs that allows for the fast localization of arteries in the roof of the mouth and has the potential to reduce complications during oral surgery.

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Diapause, a strategy to endure unfavourable conditions (e.g. cold winters) is commonly found in ectothermic organisms and is characterized by an arrest of development and reproduction, a reduction of metabolic rate, and an increased resistance to adversity.

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