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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. Relativistic perturbations in the wavelength and direction of observed stars may be used to infer spacecraft velocity which, in turn, may be used for navigation. This work develops the mathematics governing such an approach and explores its efficacy for autonomous navigation. Measurement of stellar spectral shift due to the relativistic Doppler effect is found to be ineffective in practice. Instead, measurement of the change in inter-star angle due to stellar aberration appears to be the most promising technique for navigation by the relativistic perturbation of starlight.
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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. For this purpose, enhanced green fluorescent protein (eGFP) is fused to the COOH-terminus of cdb3, and the binding of Hb to the NH2-terminus of cdb3-eGFP is quantitated by Hb-mediated quenching of cdb3-eGFP fluorescence. As expected, the intensity of cdb3-eGFP fluorescence decreases only slightly following addition of oxyHb. However, upon deoxygenation of the same Hb-cdb3 solution, the fluorescence decreases dramatically (i.e. confirming that deoxyHb exhibits much greater affinity for cdb3 than oxyHb). Using this fluorescence quenching method, we not only confirm previously established characteristics of the Hb-cdb3 interaction, but also establish an assay that can be exploited to screen for inhibitors of the sickle Hb-cdb3 interaction that accelerates sickle Hb polymerization.
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Proteína 1 de Intercambio de Anión de Eritrocito/metabolismo , Hemoglobinas/metabolismo , Proteína 1 de Intercambio de Anión de Eritrocito/química , Sitios de Unión , Bioensayo , Membrana Eritrocítica/metabolismo , Eritrocitos/metabolismo , Fluorescencia , Hemoglobinas/química , Humanos , Imagen Óptica , Unión Proteica , Estructura Terciaria de ProteínaRESUMEN
OBJECTIVES: Thrombocytosis is an uncommon hematologic abnormality that is associated with various physiologic, metabolic, inflammatory and neoplastic conditions in people and dogs. Thrombocytosis is not a well-described abnormality in cats. The objective of this study was to classify thrombocytosis in cats based on underlying disease processes and severity, and to compare this with a control population of cats. METHODS: A retrospective study was conducted by reviewing the medical records of cats with increased (>600 × 103/µl; thrombocytosis group) and normal (200-600 × 103/µl; 2:1 age-matched control group) platelet counts between 2011 and 2018. Platelet counts were estimated based on blood smear assessment in all cats. Cats were classified by the severity (mild, moderate or marked) of thrombocytosis. Diagnoses were recorded for all cases, and were classified broadly into either neoplasia, endocrine or inflammatory disease. RESULTS: In total, 158 cats were identified with thrombocytosis, with 315 cats in the control group. Non-neoplastic inflammatory disease was the most common diagnosis in both groups (54.4% in cats with thrombocytosis and 56.2% in controls; P = 0.77); however, gastrointestinal diseases were more common in cats with thrombocytosis (75.6%) when compared with controls (34.5%; P <0.0001). Neoplasia was diagnosed more frequently in cats with thrombocytosis (44.3%) compared with the control group (25.4%; P <0.0001). Round cell tumor was the most common neoplasia diagnosis in both groups, but gastrointestinal and multicentric lymphoma were diagnosed more frequently in cats with thrombocytosis compared with control cats. No association between the severity of thrombocytosis and etiology was identified. CONCLUSIONS AND RELEVANCE: Thrombocytosis in cats is more commonly associated with gastrointestinal, hepatobiliary or immune-mediated diseases when compared with a control population. Neoplasia, especially multicentric and gastrointestinal lymphoma, was more commonly diagnosed in cats with thrombocytosis when compared with control cats.
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Enfermedades de los Gatos , Enfermedades de los Perros , Sarcoma , Trombocitosis , Gatos , Animales , Perros , Estudios Retrospectivos , Trombocitosis/epidemiología , Trombocitosis/veterinaria , Trombocitosis/complicaciones , Recuento de Plaquetas/veterinaria , Sarcoma/veterinaria , Enfermedades de los Gatos/diagnóstico , Enfermedades de los Gatos/epidemiología , Enfermedades de los Gatos/etiologíaRESUMEN
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. Baseline C-reactive protein (CRP) concentrations were measured in banked sera from 91 dogs with chemotherapy-treated DLBCL using a commercially available laboratory assay. Associations between baseline serum CRP concentrations and other variables of potential prognostic significance with progression-free survival (PFS) were tested using Cox proportional hazards modeling. In the final multivariable model, only a complete (rather than partial) remission to chemotherapy (Hazard ratio [HR] 0.02; 95% confidence intervals [CI] 0.01-0.07; P < 0.001) and serum CRP concentration > 1.0 mg/dL (HR, 1.73; 95% CI, 1.02-2.92; P = 0.042) were significantly associated with PFS. The median PFS for dogs with CRP concentration ≤ 1.0 mg/dL (within the test reference interval) was 315 days, while that for dogs with CRP concentration > 1.0 mg/dL was 232 days (P = 0.06). These results suggest that baseline serum CRP concentration is independently associated with progression-free survival in dogs with DLBCL, making it a potentially useful prognostic biomarker for dogs with this cancer.
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It is often necessary to identify a pattern of observed craters in a single image of the lunar surface and without any prior knowledge of the camera's location. This so-called "lost-in-space" crater identification problem is common in both crater-based terrain relative navigation (TRN) and in automatic registration of scientific imagery. Past work on crater identification has largely been based on heuristic schemes, with poor performance outside of a narrowly defined operating regime (e.g., nadir pointing images, small search areas). This work provides the first mathematically rigorous treatment of the general crater identification problem. It is shown when it is (and when it is not) possible to recognize a pattern of elliptical crater rims in an image formed by perspective projection. For the cases when it is possible to recognize a pattern, descriptors are developed using invariant theory that provably capture all of the viewpoint invariant information. These descriptors may be pre-computed for known crater patterns and placed in a searchable index for fast recognition. New techniques are also developed for computing pose from crater rim observations and for evaluating crater rim correspondences. These techniques are demonstrated on both 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. The flow cytometric assay was evaluated for specificity with increasing concentrations of DCFH-DA and hydrogen peroxide, and a polynomial regression line was applied to determine optimal concentrations. For precision, samples were analyzed 5 consecutive times for determination of intra- and interassay variability. Stability of samples stored at 4°C for up to 48 hours after blood collection was determined with flow cytometric analysis. Coefficient of variation (CV) was considered acceptable at 20%. Baseline measurements were used to determine an expected range of median fluorescence intensity for unstimulated erythrocytes incubated with DCFH-DA. RESULTS: Erythrocytes were successfully isolated, and stimulated samples demonstrated higher median fluorescence intensity, compared with unstimulated samples. The intra-assay CV was 11.9% and 8.9% and interassay CV was 11.9% and 9.1% for unstimulated and stimulated samples, respectively. Unstimulated samples were stable for up to 24 hours, whereas stimulated samples were stable for up to 48 hours. CONCLUSIONS AND CLINICAL RELEVANCE: Flow cytometry for the measurement of reactive oxygen species in the erythrocytes of healthy dogs by use of DCFH-DA had acceptable specificity, precision, and stability. Flow cytometry is a promising technique for evaluating intraerythrocytic oxidative stress for healthy dogs.
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Eritrocitos , Peróxido de Hidrógeno , Animales , Perros , Citometría de Flujo/veterinaria , Fluoresceínas , Especies Reactivas de OxígenoRESUMEN
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. While the subpixel methods are often necessary for applications requiring best-possible accuracy, they are often susceptible to noise, use iterative methods, or require pre-processing. This work investigates a unified framework for subpixel edge and streak localization using Zernike moments with ramp-based and wedge-based signal models. The method described here is found to outperform the current state-of-the-art for digital images with common signal-to-noise ratios. Performance is demonstrated on both synthetic and real images.
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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. HYPOTHESIS: Anemic dogs will have oxidative stress when compared to healthy dogs. ANIMALS: Forty-seven dogs with anemia (10 with hemolytic anemia) and 70 healthy control dogs. METHODS: Prospective, cross-sectional study. Anemic dogs were identified from the patient population, and medical records were reviewed to classify the anemia as hemolytic or nonhemolytic. Flow cytometry was used to detect reactive oxygen species (ROS) in erythrocyte isolates. Reduced glutathione (GSH) concentrations were measured in both plasma and hemolysate samples, and vitamin E was measured in serum. RESULTS: Anemic dogs (both hemolytic and nonhemolytic) had significantly lower median RBC hemolysate GSH concentrations (3.1 µM [0.4-30.8]) when compared to healthy dogs (7.0 µM [0.5-29.7]; P = .03). Dogs with hemolytic anemia had significantly higher median plasma GSH (7.6 µM [0.4-17.8]) when compared to dogs with nonhemolytic anemia (1.6 µM [0.01-7.1]; P = .04) and healthy dogs (2.8 µM [0.1-29.9]; P < .0001). Reactive oxygen species were detectable in all samples, but there was no difference in ROS or vitamin E between groups. CONCLUSIONS AND CLINICAL IMPORTANCE: Oxidative stress is present in anemic dogs. Derangements in biomarkers of oxidative stress are different in dogs with hemolytic anemia and nonhemolytic anemia.
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Anemia Hemolítica , Anemia , Enfermedades de los Perros , Anemia/veterinaria , Anemia Hemolítica/veterinaria , Animales , Estudios Transversales , Perros , Eritrocitos , Glutatión , Estrés Oxidativo , Estudios Prospectivos , Especies Reactivas de Oxígeno , Vitamina ERESUMEN
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. METHODS: CSF samples were collected from 26 dogs. Samples were divided into four aliquots. One aliquot was analyzed immediately (control). The remaining three aliquots were mixed with either saline, fetal calf serum, or Vetstarch before storage at 4°C. Nucleated cell differentials, protein concentrations, and cell morphology scores were analyzed 48 hours later. A cell morphology score of 1 indicated no cellular degeneration; a score of 4 indicated severe degeneration. RESULTS: Samples stored in serum, saline, and Vetstarch exhibited poorer mean (±SD) morphology scores (2.4 ± 0.7, 2.6 ± 0.8, and 2.7 ± 0.9, respectively) compared with controls (1.9 ± 0.4). Samples stored in saline and Vetstarch demonstrated higher percentages of unrecognizable cells, with a median of 28 (range 0-100) and 27 (0-100), respectively; samples stored in serum had a median of 14 (range 0-67) unrecognizable. Microprotein levels of samples stored in Vetstarch were dependent on the method of protein analysis. Serum significantly increased microprotein levels. CONCLUSIONS: Vetstarch does not reduce time-dependent cellular degeneration compared with the saline diluent or serum and is, therefore, not recommended as a stabilizing agent for canine cerebrospinal fluid.
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Líquido Cefalorraquídeo/citología , Perros/líquido cefalorraquídeo , Excipientes , Derivados de Hidroxietil Almidón , Sustitutos del Plasma , Manejo de Especímenes/veterinaria , Animales , Recuento de Células/veterinaria , Femenino , MasculinoRESUMEN
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 (2.28 mmol/L and 1.8 mg/dL, respectively). Physical examination revealed a mammary mass that was cytologically described as a suspected mammary carcinoma, which was later confirmed by histologic evaluation. On surgical removal of the mass, calcium initially decreased rapidly, and within a few days was within the RI, further supporting a diagnosis of hypercalcemia of malignancy in a heifer. However, attempts to confirm this using hormone profiles (parathyroid hormone [PTH], parathyroid hormone-related protein [PTHrp], and calcitriol) were inconclusive due to the lack of validated assays and RIs for cattle. Immunohistochemical staining for PTHrP showed scattered cytoplasmic staining among the neoplastic cells, suggesting PTHrP production by these cells.
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Neoplasias de la Mama/veterinaria , Hormonas y Agentes Reguladores de Calcio/metabolismo , Calcio/metabolismo , Enfermedades de los Bovinos/diagnóstico , Hipercalcemia/veterinaria , Hormona Paratiroidea/metabolismo , Animales , Neoplasias de la Mama/diagnóstico , Neoplasias de la Mama/patología , Bovinos , Enfermedades de los Bovinos/patología , Femenino , Hipercalcemia/diagnóstico , Hipercalcemia/patología , Inmunohistoquímica/veterinariaRESUMEN
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. Postoperatively, the horse developed obstructive ileus due to adhesion formation, which required a second laparotomy. During and after surgery, the abdomen was lavaged with sodium carboxymethylcellulose (CMC). One week after the second surgery, evaluation of peritoneal fluid revealed an inflammatory exudate, with many macrophages containing amorphous to granular, pink to magenta phagocytosed material. Extracellular aggregates of the material were also observed. The material was consistent with CMC. To our knowledge, this report is the first to demonstrate the phagocytosis of CMC by peritoneal fluid macrophages.
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Líquido Ascítico/citología , Cólico/veterinaria , Enfermedades de los Caballos/patología , Animales , Carboximetilcelulosa de Sodio , Cólico/patología , Cólico/cirugía , Enfermedades de los Caballos/cirugía , Caballos , Lipoma/patología , Lipoma/cirugía , Lipoma/veterinaria , Macrófagos/fisiología , Masculino , Fagocitosis/fisiologíaRESUMEN
Two male North American elk from a commercial herd were evaluated because of a sudden onset of lethargy, anorexia, and voiding of red urine. These 2 elk were kept in the same pen as 4 other male elk that had died during the preceding 2 months. Laboratory analyses revealed anemia and intraerythrocytic parasites, later confirmed as Babesia odocoilei (a protozoal hemoparasite of cervids). Of the 240 elk remaining in the herd, 59 were screened for B odocoilei by microscopic evaluation of blood smears, protozoal culture of blood, and immunofluorescent antibody testing of serum. Of those 59 elk, 34 (58%) were infected with B odocoilei. Babesia odocoilei infection in elk can be fatal and should be considered in cases of sudden death or acute hemolytic anemia. Familiarity with the disease in elk is essential for practitioners because of the increasing popularity of commercial elk farming.
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Animales Salvajes/parasitología , Babesia/aislamiento & purificación , Babesiosis/veterinaria , Ciervos/parasitología , Animales , Antiprotozoarios/uso terapéutico , Babesiosis/tratamiento farmacológico , Babesiosis/epidemiología , Babesiosis/parasitología , Brotes de Enfermedades/prevención & control , Brotes de Enfermedades/veterinaria , Reservorios de Enfermedades/veterinaria , Eritrocitos/parasitología , Masculino , Parasitemia/tratamiento farmacológico , Parasitemia/epidemiología , Parasitemia/parasitología , Parasitemia/veterinaria , Control de Ácaros y GarrapatasAsunto(s)
Antinematodos/uso terapéutico , Filariasis/veterinaria , Filarioidea/aislamiento & purificación , Levamisol/uso terapéutico , Lagartos/parasitología , Animales , Recolección de Muestras de Sangre/veterinaria , Resultado Fatal , Femenino , Filariasis/diagnóstico , Filariasis/tratamiento farmacológico , Lagartos/sangre , Masculino , Microfilarias/aislamiento & purificación , Piel/parasitologíaRESUMEN
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<0.01). In contrast, adiponectin increased IL10 expression (P<0.05) and augmented (P<0.05) the induction of this cytokine by lipopolysaccharide (LPS). Mechanistically, the attenuation of proinflammatory cytokine production by adiponectin was associated with an attenuation of the translocation of NFkappaB to the nucleus. Either adiponectin or inhibition of ERK1/2 with U0126 diminished the induction of IL6 by LPS (P<0.05), but the combination of adiponectin and the inhibitor did not further reduce IL6 production. In contrast, the inhibitory actions of adiponectin and a p38 MAPK inhibitor (SB203580) were additive (P<0.05). These data indicate that the anti-inflammatory actions of adiponectin include suppression of IL6 and induction of IL10. In addition, we provide evidence that some of the anti-inflammatory actions of adiponectin are mediated in part by suppression of NFkappaB signaling and ERK1/2 activity.