3,291 research outputs found

    NEW AND UPDATED RECORDS FOR AMPHIBIANS AND REPTILES IN MINNESOTA, USA

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    Following the publication of the revised edition of “Amphibians and Reptiles in Minnesota” by Moriarty and Hall (2014), we accessioned several new or updated records at the Bell Museum of Natural History (JFBM). Records include digital photographs (accession number preceded by “P”) and audio recordings (accession number preceded by “AUD”). In addition, a subset of these observations were accessioned in www.HerpMapper.org. HerpMapper accession numbers are preceded by “HM” and can be viewed online. Benjamin Lowe verified species determinations. Latitude and longitude coordinates are based on datum WGS 84

    Spatial Graphs with Local Knots

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    It is shown that for any locally knotted edge of a 3-connected graph in S3S^3, there is a ball that contains all of the local knots of that edge and is unique up to an isotopy setwise fixing the graph. This result is applied to the study of topological symmetry groups of graphs embedded in S3S^3.Comment: 20 pages, 3 figures; in v. 2 the proof of Theorem 1 has been clarified, and other minor revisions have been mad

    Experimental and computational characterization of a modified GEC cell for dusty plasma experiments

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    A self-consistent fluid model developed for simulations of micro- gravity dusty plasma experiments has for the first time been used to model asymmetric dusty plasma experiments in a modified GEC reference cell with gravity. The numerical results are directly compared with experimental data and the experimentally determined dependence of global discharge parameters on the applied driving potential and neutral gas pressure is found to be well matched by the model. The local profiles important for dust particle transport are studied and compared with experimentally determined profiles. The radial forces in the midplane are presented for the different discharge settings. The differences between the results obtained in the modified GEC cell and the results first reported for the original GEC reference cell are pointed out

    Epidural Hematoma Following Cervical Spine Surgery.

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    STUDY DESIGN: A multicentered retrospective case series. OBJECTIVE: To determine the incidence and circumstances surrounding the development of a symptomatic postoperative epidural hematoma in the cervical spine. METHODS: Patients who underwent cervical spine surgery between January 1, 2005, and December 31, 2011, at 23 institutions were reviewed, and all patients who developed an epidural hematoma were identified. RESULTS: A total of 16 582 cervical spine surgeries were identified, and 15 patients developed a postoperative epidural hematoma, for a total incidence of 0.090%. Substantial variation between institutions was noted, with 11 sites reporting no epidural hematomas, and 1 site reporting an incidence of 0.76%. All patients initially presented with a neurologic deficit. Nine patients had complete resolution of the neurologic deficit after hematoma evacuation; however 2 of the 3 patients (66%) who had a delay in the diagnosis of the epidural hematoma had residual neurologic deficits compared to only 4 of the 12 patients (33%) who had no delay in the diagnosis or treatment (P = .53). Additionally, the patients who experienced a postoperative epidural hematoma did not experience any significant improvement in health-related quality-of-life metrics as a result of the index procedure at final follow-up evaluation. CONCLUSION: This is the largest series to date to analyze the incidence of an epidural hematoma following cervical spine surgery, and this study suggest that an epidural hematoma occurs in approximately 1 out of 1000 cervical spine surgeries. Prompt diagnosis and treatment may improve the chance of making a complete neurologic recovery, but patients who develop this complication do not show improvements in the health-related quality-of-life measurements

    C5 Palsy After Cervical Spine Surgery: A Multicenter Retrospective Review of 59 Cases.

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    STUDY DESIGN: A multicenter, retrospective review of C5 palsy after cervical spine surgery. OBJECTIVE: Postoperative C5 palsy is a known complication of cervical decompressive spinal surgery. The goal of this study was to review the incidence, patient characteristics, and outcome of C5 palsy in patients undergoing cervical spine surgery. METHODS: We conducted a multicenter, retrospective review of 13 946 patients across 21 centers who received cervical spine surgery (levels C2 to C7) between January 1, 2005, and December 31, 2011, inclusive. P values were calculated using 2-sample t test for continuous variables and χ(2) tests or Fisher exact tests for categorical variables. RESULTS: Of the 13 946 cases reviewed, 59 patients experienced a postoperative C5 palsy. The incidence rate across the 21 sites ranged from 0% to 2.5%. At most recent follow-up, 32 patients reported complete resolution of symptoms (54.2%), 15 had symptoms resolve with residual effects (25.4%), 10 patients did not recover (17.0%), and 2 were lost to follow-up (3.4%). CONCLUSION: C5 palsy occurred in all surgical approaches and across a variety of diagnoses. The majority of patients had full recovery or recovery with residual effects. This study represents the largest series of North American patients reviewed to date

    High-Resolution Mass Spectrometric Characterization of Molecules on Biochar from Pyrolysis and Gasification of Switchgrass

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    Organic molecules entrapped in biochar during pyrolysis and gasification of switchgrass have been studied using high-resolution mass spectrometry. Two solvent systems, toluene and a mixture of water/methanol, were used to extract hydrophobic aromatic compounds and hydrophilic polar compounds, respectively. Laser desorption ionization and atmospheric pressure photoionization were used for toluene extracts, while electrospray ionization was used for water/methanol extracts, followed by orbitrap mass spectrometric data acquisition. Molecular compounds previously known in bio-oils were observed for fast pyrolysis biochar, with phenolic and carbohydrate-derived compounds originating from the pyrolysis of lignin and holocellulose, respectively. In contrast, polycyclic aromatic hydrocarbons (PAHs) with various ring sizes were observed for gasification biochar and also for slow pyrolysis biochar in low abundance

    Circulating αKlotho influences phosphate handling by controlling FGF23 production

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    The FGF23 coreceptor αKlotho (αKL) is expressed as a membrane-bound protein (mKL) that forms heteromeric complexes with FGF receptors (FGFRs) to initiate intracellular signaling. It also circulates as an endoproteolytic cleavage product of mKL (cKL). Previously, a patient with increased plasma cKL as the result of a translocation [t(9;13)] in the αKLOTHO (KL) gene presented with rickets and a complex endocrine profile, including paradoxically elevated plasma FGF23, despite hypophosphatemia. The goal of this study was to test whether cKL regulates phosphate handling through control of FGF23 expression. To increase cKL levels, mice were treated with an adeno-associated virus producing cKL. The treated groups exhibited dose-dependent hypophosphatemia and hypocalcemia, with markedly elevated FGF23 (38 to 456 fold). The animals also manifested fractures, reduced bone mineral content, expanded growth plates, and severe osteomalacia, with highly increased bone Fgf23 mRNA (>150 fold). cKL activity in vitro was specific for interactions with FGF23 and was FGFR dependent. These results demonstrate that cKL potently stimulates FGF23 production in vivo, which phenocopies the KL translocation patient and metabolic bone syndromes associated with elevated FGF23. These findings have important implications for the regulation of αKL and FGF23 in disorders of phosphate handling and biomineralization

    Relationship between the magnitude of intraocular pressure during an episode of acute elevation and retinal damage four weeks later in rats

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    PURPOSE: To determine relationship between the magnitude of intraocular pressure (IOP) during a fixed-duration episode of acute elevation and the loss of retinal function and structure 4 weeks later in rats. METHODS: Unilateral elevation of IOP (105 minutes) was achieved manometrically in adult Brown Norway rats (9 groups; n = 4 to 8 each, 10-100 mm Hg and sham control). Full-field ERGs were recorded simultaneously from treated and control eyes 4 weeks after IOP elevation. Scotopic ERG stimuli were white flashes (-6.04 to 2.72 log cd.s.m(-2)). Photopic ERGs were recorded (1.22 to 2.72 log cd.s.m(-2)) after 15 min of light adaptation (150 cd/m(2)). Relative amplitude (treated/control, %) of ERG components versus IOP was described with a cummulative normal function. Retinal ganglion cell (RGC) layer density was determined post mortem by histology. RESULTS: All ERG components failed to recover completely normal amplitudes by 4 weeks after the insult if IOP was 70 mmHg or greater during the episode. There was no ERG recovery at all if IOP was 100 mmHg. Outer retinal (photoreceptor) function demonstrated the least sensitivity to prior acute IOP elevation. ERG components reflecting inner retinal function were correlated with post mortem RGC layer density. CONCLUSIONS: Retinal function recovers after IOP normalization, such that it requires a level of acute IOP elevation approximately 10 mmHg higher to cause a pattern of permanent dysfunction similar to that observed during the acute event. There is a 'threshold' for permanent retinal functional loss in the rat at an IOP between 60 and 70 mmHg if sustained for 105 minutes or more
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