Publications by authors named "Christian John"

Plant phenological dynamics have been well studied in relation to abiotic conditions and climate change, but comparatively poorly studied in relation to herbivory. In contrast, plant abundance dynamics have been well studied in relation to abiotic conditions and herbivory, but poorly studied in relation to phenology. Consequently, the contribution of herbivory to plant phenological dynamics and therefrom to plant abundance dynamics remains obscure.

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This paper documents the results from the highly successful Lunar flashlight Optical Navigation Experiment with a Star tracker (LONEStar). Launched in December 2022, Lunar Flashlight (LF) was a NASA-funded technology demonstration mission. After a propulsion system anomaly prevented capture in lunar orbit, LF was ejected from the Earth-Moon system and into heliocentric space.

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Climate change reduces snowpack, advances snowmelt phenology, drives summer warming, alters growing season precipitation regimes, and consequently modifies vegetation phenology in mountain systems. Elevational migrants track spatial variation in seasonal plant growth by moving between ranges at different elevations during spring, so climate-driven vegetation change may disrupt historic benefits of migration. Elevational migrants can furthermore cope with short-term environmental variability by undertaking brief vertical movements to refugia when sudden adverse conditions arise.

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Iatrogenic venous compression syndrome is defined by extrinsic vein compression due to medical hardware, particularly relevant after joint replacement surgeries. Inserting medical hardware can lead to immediate risks such as deep vein thrombosis and pulmonary embolisms due to local tissue inflammation. The long-term issues include venous insufficiency due to chronic vessel irritation, subsequently causing intimal proliferation and thickening.

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Article Synopsis
  • - The study aimed to classify thrombocytosis (high platelet counts) in cats based on various diseases and severity, comparing it to a control group of cats with normal platelet levels.
  • - Researchers analyzed medical records from 2011 to 2018, identifying 158 cats with thrombocytosis and 315 control cats, with non-neoplastic inflammatory disease being the most common diagnosis in both groups.
  • - Thrombocytosis was linked to higher incidences of gastrointestinal diseases and neoplasia in cats, particularly gastrointestinal and multicentric lymphoma, but no correlation was found between the severity of thrombocytosis and its underlying causes.
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Biodiversity is declining globally in response to multiple human stressors, including climate forcing. Nonetheless, local diversity trends are inconsistent in some taxa, obscuring contributions of local processes to global patterns. Arctic tundra diversity, including plants, fungi, and lichens, declined during a 15-year experiment that combined warming with exclusion of large herbivores known to influence tundra vegetation composition.

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Prognostic factors for dogs with diffuse large B-cell lymphoma (DLBCL) are poorly characterized. Prior reports suggest that dogs with a systemic inflammatory response at the time of lymphoma diagnosis experience inferior survival times. However, no specific biomarkers of inflammation have been identified as prognostic indicators in dogs with DLBCL.

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Assumptions about factors such as climate in shaping species' realized and potential distributions underlie much of conservation planning and wildlife management. Climate and climatic change lead to shifts in species distributions through both direct and indirect ecological pressures. Distributional shifts may be particularly important if range overlap is altered between interacting species, or between species and protected areas.

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Gale crater, the field site for NASA's Mars Science Laboratory Curiosity rover, contains a diverse and extensive record of aeolian deposition and erosion. This study focuses on a series of regularly spaced, curvilinear, and sometimes branching bedrock ridges that occur within the Glen Torridon region on the lower northwest flank of Aeolis Mons, the central mound within Gale crater. During Curiosity's exploration of Glen Torridon between sols ∼2300-3080, the rover drove through this field of ridges, providing the opportunity for in situ observation of these features.

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Article Synopsis
  • The text addresses the challenge of identifying craters in lunar images without prior knowledge of camera location, which is called the "lost-in-space" crater identification problem.
  • Traditional methods have struggled outside specific conditions, prompting a need for a more rigorous mathematical approach to this problem.
  • The work presents new invariant descriptors for recognizing elliptical crater patterns and introduces techniques for computing camera pose and assessing crater correspondences, validated through synthetic and real images.
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Objective: To validate the use of a flow cytometric assay that uses 2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA) to measure reactive oxygen species in the erythrocytes of healthy dogs.

Animals: 50 healthy adult dogs.

Procedures: Erythrocytes were incubated with DCFH-DA or a vehicle control (dimethyl sulfoxide), then incubated with (stimulated) or without (unstimulated) hydrogen peroxide.

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Background: Red blood cells (RBC) are uniquely susceptible to oxidative injury. Oxidative stress is both a cause for, and effect, of anemia in people but this has been minimally documented in dogs.

Objective: To describe direct and indirect markers of oxidative stress in anemic dogs.

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Many modern sensing systems rely on the accurate extraction of measurement data from digital images. The localization of edges and streaks in digital images is an important example of this type of measurement, with these techniques appearing in many image processing pipelines. Several approaches attempt to solve this problem at both the pixel level and subpixel level.

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Background: A challenge of cerebrospinal fluid (CSF) analysis is the time-dependent degradation of nucleated cells, impeding accurate interpretation. CSF additives have been used to delay cell degradation; however, stabilizing agents, including serum, can alter microprotein levels.

Objectives: This study aimed to determine if the hydroxyethyl starch, Vetstarch, is effective at preserving nucleated cell morphology in CSF compared with the saline diluent or serum without altering microprotein levels.

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Future space exploration missions require increased autonomy. This is especially true for navigation, where continued reliance on Earth-based resources is often a limiting factor in mission design and selection. In response to the need for autonomous navigation, this work introduces the StarNAV framework that may allow a spacecraft to autonomously navigate anywhere in the Solar System (or beyond) using only passive observations of naturally occurring starlight.

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Mammary carcinoma is rare in cattle with only a handful of cases found in the literature, and none have reported an associated hypercalcemia. An 8-year-old Holstein-Friesian heifer was presented to the Purdue University Veterinary Teaching Hospital's Large Animal Hospital with a 3-month history of lethargy. Laboratory abnormalities included ionized hypercalcemia and hypophosphatemia (2.

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To generate bright water-window (WW) soft x rays (2.3-4.4 nm), gold slab targets were irradiated with laser pulses (1064 nm, 7 ns, 1 J).

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Oncogenic Ras causes proliferation followed by premature senescence in primary cells, an initial barrier to tumor development. The role of endoplasmic reticulum (ER) stress and the unfolded protein response (UPR) in regulating these two cellular outcomes is poorly understood. During ER stress, the inositol requiring enzyme 1α (IRE1α) endoribonuclease (RNase), a key mediator of the UPR, cleaves mRNA to generate a potent transcription factor adaptive toward ER stress.

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Oxygen tension has emerged as a potent regulator of multiple erythrocyte properties, including glucose metabolism, cell volume, ATP release, and cytoskeletal organization. Because hemoglobin (Hb)(1) binds to the cytoplasmic domain of band 3 (cdb3) in an oxygen dependent manner, with deoxyHb exhibiting significantly greater affinity for cdb3 than oxyHb, the deoxyHb-cdb3 interaction has been hypothesized to constitute the molecular switch for all O2-controlled erythrocyte processes. In this study, we describe a rapid and accurate method for quantitating the interaction of deoxyHb binding to cdb3.

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Stimulation of the aryl hydrocarbon receptor (AHR) by xenobiotics is known to affect epidermal differentiation and skin barrier formation. The physiological role of endogenous AHR signaling in keratinocyte differentiation is not known. We used murine and human skin models to address the hypothesis that AHR activation is required for normal keratinocyte differentiation.

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The partial pressure of oxygen constitutes an important factor in the regulation of human erythrocyte physiology, including control of cell volume, membrane structure, and glucose metabolism. Because band 3 is thought to be involved in all three processes and because binding of hemoglobin (Hb) to the cytoplasmic domain of band 3 (cdb3) is strongly oxygen-dependent, the possibility that the reversible association of deoxyhemoglobin (deoxyHb) with cdb3 might constitute an O(2)-dependent sensor that mediates O(2)-regulated changes in erythrocyte properties arises. While several lines of evidence support this hypothesis, a major opposing argument lies in the fact that the deoxyHb binding sequence on human cdb3 is not conserved.

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A 16-year-old castrated male Arabian horse was presented to the Purdue University Veterinary Teaching Hospital with a 4-hour history of colic. Initial examinations provided strong evidence for small intestinal obstruction. Abdominal surgery revealed a strangulating lipoma, and 25 feet of small intestine were resected.

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Na(18)F, an early bone scintigraphy agent, is poised to reenter mainstream clinical imaging with the present generations of stand-alone PET and PET/CT hybrid scanners. (18)F PET scans promise improved imaging quality for both benign and malignant bone disease, with significantly improved sensitivity and specificity over conventional planar and SPECT bone scans. In this article, basic acquisition information will be presented along with examples of studies related to oncology, sports medicine, and general orthopedics.

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Adiponectin, an adipocyte-derived hormone, attenuates the production of TNFalpha by activated human macrophages. In the present study, we used porcine blood-derived macrophages to test the hypothesis that the anti-inflammatory action of adiponectin includes suppression of IL6 and an induction of IL10. Adiponectin suppressed both TNFalpha and IL6 production in macrophages activated with lipopolysaccharide (P<0.

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