653 research outputs found

    Tractor Hacking

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    Tractor hacking arose from tractor owners\u27 desire for full control over the tractors they purchase. Tractor manufacturers set strict security on the electrical components of their tractors, making it difficult for tractor owners to diagnose and monitor their tractors on their own. The UltraBlue Tractor Hacking project is a solution to this problem, allowing tractor owners to perform diagnostics and monitor the equipment they purchased without having to go through dealerships. From talking to farmers, we found that they valued a diagnostic tool that allows for clearing and resetting Diagnostic Trouble Codes (DTCs), viewing diagnostic data pertaining to a specific fault that was detected by an electronic control unit (ECU) in the tractor, and obtaining a repair plan from the diagnostics data. This project is an attempt to provide tractor owners and technicians the hardware and software necessary to diagnose, monitor, and repair their equipment without the need for manufacturer technicians and repair services. Our product is a device that utilizes the SAE J1939 standard to implement diagnostic and monitoring functionalities on tractors that conform to the SAE J1939 standard. Both the hardware and software have gone through rigorous testing and validation to ensure that we are following the standards set by SAE J1939. After that was completed, we tested our device on John Deere tractors to test the effectiveness of our implementation of a diagnostic tool. However, the results of these tests led us to conclude that not all John Deere tractors conform to the SAE J1939 standard

    Missouri mail-in record farms 1964 to 1973 : investments, productions, costs and returns

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    Cover title

    Missouri hog farmers : factors affecting production decisions

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    Cover title.Includes bibliographical references (page 19)

    Functional visual sensitivity to ultraviolet wavelengths in the Pileated Woodpecker (\u3ci\u3eDryocopus pileatus\u3c/i\u3e), and its influence on foraging substrate selection

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    Most diurnal birds are presumed visually sensitive to near ultraviolet (UV)wavelengths, however, controlled behavioral studies investigating UV sensitivity remain few. Although woodpeckers are important as primary cavity excavators and nuisance animals, published work on their visual systems is limited. We developed a novel foraging-based behavioral assay designed to test UV sensitivity in the Pileated Woodpecker (Dryocopus pileatus). We acclimated 21 wild-caught woodpeckers to foraging for frozen mealworms within 1.2 m sections of peeled cedar (Thuja spp.) poles.We then tested the functional significance of UV cues by placing frozen mealworms behind UV-reflective covers, UV-absorptive covers, or decayed red pine substrates within the same 1.2 m poles in independent experiments. Behavioral responses were greater toward both UV-reflective and UV-absorptive substrates in three experiments. Study subjects therefore reliably differentiated and attended to two distinct UV conditions of a foraging substrate. Cue-naïve subjects showed a preference for UV-absorptive substrates, suggesting that woodpeckers may be pre-disposed to foraging from such substrates. Behavioral responses were greater toward decayed pine substrates (UV-reflective) than sound pine substrates suggesting that decayed pine can be a useful foraging cue. The finding that cue-naïve subjects selected UV-absorbing foraging substrates has implications for ecological interactions of woodpeckers with fungi.Woodpeckers transport fungal spores, and communication methods analogous to those of plant-pollinator mutualisms (i.e. UV-absorbing patterns) may have evolved to support woodpecker-fungus mutualisms

    Visual cues for woodpeckers: light reflectance of decayed wood varies by decay fungus

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    The appearance of wood substrates is likely relevant to bird species with life histories that require regular interactions with wood for food and shelter. Woodpeckers detect decayed wood for cavity placement or foraging, and some species may be capable of detecting trees decayed by specific fungi; however, a mechanism allowing for such specificity remains unidentified.We hypothesized that decay fungi associated with woodpecker cavity sites alter the substrate reflectance in a species-specific manner that is visually discriminable by woodpeckers. We grew 10 species of wood decay fungi from pure cultures on sterile wood substrates of 3 tree species. We then measured the relative reflectance spectra of decayed and control wood wafers and compared them using the receptor noise-limited (RNL) color discrimination model. The RNL model has been used in studies of feather coloration, egg shells, flowers, and fruit to model how the colors of objects appear to birds. Our analyses indicated 6 of 10 decayed substrate/control comparisons were above the threshold of discrimination (i.e., indicating differences discriminable by avian viewers), and 12 of 13 decayed substrate comparisons were also above threshold for a hypothetical woodpecker. We conclude that woodpeckers should be capable of visually detecting decayed wood on trees where bark is absent, and they should also be able to detect visually species-specific differences in wood substrates decayed by fungi used in this study. Our results provide evidence for a visual mechanism by which woodpeckers could identify and select substrates decayed by specific fungi, which has implications for understanding ecologically important woodpecker–fungus interactions. El aspecto de los sustratos de madera posiblemente sea relevante para especies de aves que tienen historias de vida que dependen de interacciones regulares con la madera para alimentaci´on y resguardo. Los pa´jaros carpinteros detectan la madera degradada para establecer sus cavidades o para forrajear, y algunas especies podr´ıan ser capaces de detectar a´rboles que son degradadas por alg´un hongo en particular. Sin embargo, a´un no se identifica un mecanismo que permita identificar tal especificidad. Nuestra hip´otesis es que los hongos xil ´ofagos asociados a sitios con cavidades para carpinteros alteran la reflectancia del sustrato en una manera espec´ıfica a especie que es visualmente discernible para los carpinteros. Cultivamos 10 especies de hongos xil ´ofagos a partir de cultivos puros en sustratos est´eriles de madera de tres especies de a´rboles. A continuaci´on, medimos el espectro de reflectancia de la madera de la madera degradada y trozos de madera control, y las comparamos entre s´ı usando el modelo de discriminaci´on de color del receptor de ruido limitado (RNL, por sus siglas en ingl´es). El modelo RNL ha sido utilizado en estudios de coloraci´on de plumas, cascar´on de huevo, flores y frutos para modelar c´omo perciben las aves el color de los objetos. Nuestros ana´lisis indican que 6 de 10 comparaciones sustrato/control estuvieron por encima del umbral de discriminaci´on (e.g., indicando diferencias discernibles por observadores aviares) y que las comparaciones de 12 de los 13 sustratos degradados estuvieron por encima del umbral para un carpintero hipot´etico. Concluimos que los carpinteros deben ser capaces de detectar visualmente la madera degradada en a´rboles donde la corteza esta´ ausente y tambi´en deben detectar visualmente diferencias espec´ıficas a especie en los sustratos de madera degradada por los hongos utilizados en este estudio. Nuestros resultados proveen evidencia de un mecanismo visual por medio del cual los pa´jaros carpinteros pueden identificar y seleccionar los sustratos degradados por hongos espec´ıficos, lo cual tiene implicaciones en nuestro entendimiento de las importantes interacciones entre carpinteros y hongos

    Late Silurian plutons in Yucatan

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    This is the published version. Copyright 1996 American Geophysical Union. All Rights Reserved.U-Pb measurements of zircons from two composite plutons in the Maya Mountains of the Yucatan Block (Belize) give Late Silurian ages. Zircons from one of the five compositional phases of the Mountain Pine Ridge pluton yield an age of 418±3.6 Ma. A second compositional phase gives a minimum age of 404 Ma, and zircons from a third phase, although plagued with high common Pb, yield ages consistent with the other two. Zircons from one compositional phase of the Hummingbird-Mullins River pluton indicate an age of about 410–420 Ma. These data demonstrate that two of the three Maya Mountains plutons residing among the strata of the Late Pennsylvanian through Permian Santa Rosa Group are older than that sedimentation. Although the third pluton was not dated, both the similarity of sedimentary facies patterns adjacent to it to those adjacent to one of the plutons dated as Late Silurian and a published single Rb-Sr age of 428 ± 41 Ma suggest this third pluton also was emergent during Santa Rosa deposition. Thus the new U/Pb dates and other data suggest that all three Maya Mountains plutons pre-date Late Carboniferous sedimentation and that none intrude the Santa Rosa Group. Although very uniform ages of about 230 Ma amongst all plutons, derived from abundant earlier dating by the K-Ar system, led to the conclusion that intrusion mostly had occurred in the Late Triassic, the U-Pb ages (obtained from the same sites as the K-Ar dates) demonstrate that the K-Ar ages do not derive from a Late Triassic intrusive episode. The K-Ar dates probably are a signature of the rifting associated with Pangean breakup and formation of the Gulf of Mexico. In a reconstructed Pangea, the position of the Maya Mountains Late Silurian plutons suggests that the Late Silurian Acadian-Caledonian orogen of eastern North America extended through the region of the future Gulf of Mexico. Finally, the U-Pb ages of the Maya Mountains plutons are the same as those of a group of shocked zircons found in the Chicxulub impact structure and its fallout layer. The presence of these ages in both locations suggests that the Maya Mountains exposures may be representative of the basement of the Yucatan Block, hence of the basement impacted by the Chicxulub object

    Chronic hindlimb ischemia impairs functional vasodilation and vascular reactivity in mouse feed arteries

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    Vasodilation of lower leg arterioles is impaired in animal models of chronic peripheral ischemia. In addition to arterioles, feed arteries are a critical component of the vascular resistance network, accounting for as much as 50% of the pressure drop across the arterial circulation. Despite the critical importance of feed arteries in blood flow control, the impact of ischemia on feed artery vascular reactivity is unknown. At 14 days following unilateral resection of the femoral–saphenous artery–vein pair, functional vasodilation of the profunda femoris artery was severely impaired, 11 ± 9 versus 152 ± 22%. Although endothelial and smooth muscle-dependent vasodilation were both impaired in ischemic arteries compared to control arteries (Ach: 40 ± 14 versus 81 ± 11%, SNP: 43 ± 12 versus and 85 ± 11%), the responses to acetylcholine and sodium nitroprusside were similar, implicating impaired smooth muscle-dependent vasodilation. Conversely, vasoconstriction responses to norepinephrine were not different between ischemic and control arteries, −68 ± 3 versus −66 ± 3%, indicating that smooth muscle cells were functional following the ischemic insult. Finally, maximal dilation responses to acetylcholine, ex vivo, were significantly impaired in the ischemic artery compared to control, 71 ± 9 versus 97 ± 2%, despite a similar generation of myogenic tone to the same intravascular pressure (80 mmHg). These data indicate that ischemia impairs feed artery vasodilation by impairing the responsiveness of the vascular wall to vasodilating stimuli. Future studies to examine the mechanistic basis for the impact of ischemia on vascular reactivity or treatment strategies to improve vascular reactivity following ischemia could provide the foundation for an alternative therapeutic paradigm for peripheral arterial occlusive disease

    Alterations in functional connectivity for language in prematurely born adolescents

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    Recent data suggest recovery of language systems but persistent structural abnormalities in the prematurely born. We tested the hypothesis that subjects who were born prematurely develop alternative networks for processing language. Subjects who were born prematurely (n = 22; 600–1250 g birth weight), without neonatal brain injury on neonatal cranial ultrasound, and 26 term control subjects were examined with a functional magnetic resonance imaging (fMRI) semantic association task, the Wechsler Intelligence Scale for Children-III (WISC-III) and the Clinical Evaluation of Language Fundamentals (CELF). In-magnet task accuracy and response times were calculated, and fMRI data were evaluated for the effect of group on blood oxygen level dependent (BOLD) activation, the correlation between task accuracy and activation and the functional connectivity between regions activating to task. Although there were differences in verbal IQ and CELF scores between the preterm (PT) and term control groups, there were no significant differences for either accuracy or response time for the in-magnet task. Both groups activated classic semantic processing areas including the left superior and middle temporal gyri and inferior frontal gyrus, and there was no significant difference in activation patterns between groups. Clear differences between the groups were observed in the correlation between task accuracy and activation to task at P < 0.01, corrected for multiple comparisons. Left inferior frontal gyrus correlated with accuracy only for term controls and left sensory motor areas correlated with accuracy only for PT subjects. Left middle temporal gyri correlated with task accuracy for both groups. Connectivity analyses at P < 0.001 revealed the importance of a circuit between left middle temporal gyri and inferior frontal gyrus for both groups. In addition, the PT subjects evidenced greater connectivity between traditional language areas and sensory motor areas but significantly fewer correlated areas within the frontal lobes when compared to term controls. We conclude that at 12 years of age, children born prematurely and children born at term had no difference in performance on a simple lexical semantic processing task and activated similar areas. Connectivity analyses, however, suggested that PT subjects rely upon different neural pathways for lexical semantic processing when compared to term controls. Plasticity in network connections may provide the substrate for improving language skills in the prematurely born

    Ion microprobe determination of sulfur isotope variations in iron sulfides from the Post/ Betze sediment-hosted disseminated gold deposit, Nevada, USA

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    Secondary ion mass spectrometric analyses of ore samples from the Post/Betze sedimenthosted disseminated gold deposit were utilized to constrain elemental distribution of Au and As in iron sulfide phases. Most of the Au was deposited very early in the paragenetic sequence. Although Au and As are covariant in arsenian pyrite, Au apparently was depleted much more rapidly from the hydrothermal solutions than was As.Sensitive high-resolution ion microprobe (SHRIMP) sulfur isotope analyses of iron sulfides from the Post/Betze deposit vary widely from [delta]34S = -29 to 23[per mille sign] and provide important information on the origin of sulfur and constraints on depositional mechanisms. Ore solutions had high [delta]34S values and were most likely derived, at least in part, from thermochemical reduction of lower Paleozoic seawater-derived sulfate, possibly bedded barite. Late-stage ore fluids ([delta]34Ssulfide = -12 to -29[per mille sign]) are extremely depleted in 34S relative to main-stage ore fluids ([delta]34Ssulfide = 16-23[per mille sign]). Although such low [delta]34S values can be generated hypothetically from the original ore fluids by oxidation (possibly boiling), the stability of pyrite is compromised. Introduction of and mixing with Fe-rich fluids is necessary to deposit pyrite having low isotopic values.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/30896/1/0000565.pd
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