286 research outputs found
Drumlins in North Dakota
The term \u27\u27drumlin is of Gaelic origin being derived from druim, a word for a mound or rounded hill, and has been used in glaciological literature since 1866. But with the increased study of subglacial ·shear features the terminology has become very inconsistent. The glacially formed longitudinal ridges found in northeastern North Dakota can be referred to as either drumlins or drumlinized ground moraine depending on their size, shape, composition, and interpreted origin.
Most of the drumlins observed in North Dakota are cored with glacial outwash deposits but exceptions do exist. Drumlins cored with Pierre shale occur north of Langdon, North Dakota, and till-cored drumlin ridges are present .south of Devils Lake, North Dakota. Longitudinal ridges that are generally less than 5 feet in height and .made up entirely of till are present in many locations in northeastern North Dakota.
Based on limited field observations, a study of drumlin literature, and an application of several principles of soil mechanics, a model for the formation of drumlins cored with sand and gravel has been developed. Internal pore-water pressure, effective stress (intergranular stress on the sediment), load pressure of the overlying ice, and permeability of the sediment are taken into consideration. Shear strength of the sediment is a function of effective stress. High pore-water pressure reduces the strength of the material.
If outwash from a previous ice advance contained channelized sand and gravel deposits (great permeability--rapid discharge capacity) surrounded by sediment with a large amount of silt and clay (slight permeability--slow discharge capacity) shear strength would be an important factor in erosion occurring during a second advance. A sand and gravel body with a greater effective stress would survive a shear stress that would erode the surrounding material. The sand-and-gravel-cored drumlin ridges could be the remnants of an advance where shearing forces eroded the surrounding sediment
Suppression of Urinary Voiding âon Demandâ by High-Frequency Stimulation of the S1 Sacral Nerve Root in Anesthetized Rats
Recurrences in Driven Quantum Systems
We consider an initially bound quantum particle subject to an external
time-dependent field. When the external field is large, the particle shows a
tendency to repeatedly return to its initial state, irrespective of whether the
frequency of the field is sufficient for escape from the well. These
recurrences, which are absent in a classical calculation, arise from the system
evolving primarily like a free particle in the external field.Comment: 10 pages in RevTeX format, with three PS files appende
Increased interaction of F508del-CFTR with K8/K18 cytokeratin network by direct binding of K8 to NBD1
Aspirin and some other nonsteroidal anti-inflammatory drugs inhibit cystic fibrosis transmembrane conductance regulator protein gene expression in T-84 cells.
Cystic fibrosis (CF) is caused by mutations in the CF gene, which encodes CF transmembrane conductance regulator protein (CFTR), a transmembrane protein that acts as a cAMP-regulated chloride channel The disease is characterized by inflammation but the relationship between inflammation, abnormal transepithelial ion transport, and the clinical manifestations of CF are uncertain. The present study was undertaken to determine whether three nonsteroidal anti-inflammatory drugs (NSAIDs) (aspirin, ibuprofen, and indomethacin) modulate CFTR gene expression in T-84 cells. Treatment with NSAIDs reduced CFTR transcripts, and decreased cAMP-stimulated anion fluxes, an index of CFTR function. However, the two phenomena occurred at different concentrations of both drugs. The results indicate that NSAIDs can regulate both CFTR gene expression and the function of CFTR-related chloride transport, and suggest that NSAIDs act via multiple transduction pathways
Suppression of Urinary Voiding by Conditional High Frequency Stimulation of the Pelvic Nerve in Conscious Rats:Pelvic nerve stimulation suppresses urinary voiding
Female Wistar rats were instrumented to record bladder pressure and to stimulate the left pelvic nerve. Repeated voids were induced by continuous infusion of saline into the bladder (11.2 ml/h) via a T-piece in the line to the bladder catheter. In each animal tested (n = 6) high frequency pelvic nerve stimulation (1â3 kHz, 1â2 mA sinusoidal waveform for 60 s) applied within 2 s of the onset of a sharp rise in bladder pressure signaling an imminent void was able to inhibit micturition. Voiding was modulated in three ways: (1) Suppression of voiding (four rats, n = 13 trials). No fluid output or a very small volume of fluid expelled (<15% of the volume expected based on the mean of the previous 2 or 3 voids). Voiding suppressed for the entirety of the stimulation period (60 s) and resumed within 37 s of stopping stimulation. (2) Void deferred (four rats, n = 6 trials). The imminent void was suppressed (no fluid expelled) but a void occurred later in the stimulation period (12â44 s, mean 24.5 ± 5.2 s after the onset of the stimulation). (3) Reduction in voided volume (five rats, n = 20 trials). Voiding took place but the volume of fluid voided was 15â80% (range 21.8â77.8%, mean 45.3 ± 3.6%) of the volume expected from the mean of the preceding two or three voids. Spontaneous voiding resumed within 5 min of stopping stimulation. Stimulation during the filling phase in between voids had no effect. The experiments demonstrate that conditional high frequency stimulation of the pelvic nerve started at the onset of an imminent void can inhibit voiding. The effect was rapidly reversible and was not accompanied by any adverse behavioral side effects
Eicosanoid Release Is Increased by Membrane Destabilization and CFTR Inhibition in Calu-3 Cells
The antiinflammatory protein annexin-1 (ANXA1) and the adaptor S100A10 (p11), inhibit cytosolic phospholipase A2 (cPLA2α) by direct interaction. Since the latter is responsible for the cleavage of arachidonic acid at membrane phospholipids, all three proteins modulate eicosanoid production. We have previously shown the association of ANXA1 expression with that of CFTR, the multifactorial protein mutated in cystic fibrosis. This could in part account for the abnormal inflammatory status characteristic of this disease. We postulated that CFTR participates in the regulation of eicosanoid release by direct interaction with a complex containing ANXA1, p11 and cPLA2α. We first analyzed by plasmon surface resonance the in vitro binding of CFTR to the three proteins. A significant interaction between p11 and the NBD1 domain of CFTR was found. We observed in Calu-3 cells a rapid and partial redistribution of all four proteins in detergent resistant membranes (DRM) induced by TNF-α. This was concomitant with increased IL-8 synthesis and cPLA2α activation, ultimately resulting in eicosanoid (PGE2 and LTB4) overproduction. DRM destabilizing agent methyl-ÎČ-cyclodextrin induced further cPLA2α activation and eicosanoid release, but inhibited IL-8 synthesis. We tested in parallel the effect of short exposure of cells to CFTR inhibitors Inh172 and Gly-101. Both inhibitors induced a rapid increase in eicosanoid production. Longer exposure to Inh172 did not increase further eicosanoid release, but inhibited TNF-α-induced relocalization to DRM. These results show that (i) CFTR may form a complex with cPLA2α and ANXA1 via interaction with p11, (ii) CFTR inhibition and DRM disruption induce eicosanoid synthesis, and (iii) suggest that the putative cPLA2/ANXA1/p11/CFTR complex may participate in the modulation of the TNF-α-induced production of eicosanoids, pointing to the importance of membrane composition and CFTR function in the regulation of inflammation mediator synthesis
Anthocyanins, phenols, and antioxidant activity in blackberry juice with plant extracts addition during heating
In this work the influence of addition of different plant extracts (olive leaf, green tea, pine bark PE 95%, pine bark PE 5:1, red wine PE 30%, red wine PE 4:1, and bioflavonoids) to blackberry juice during heating (at 30, 50, 70 and 90 °C) on the anthocyanin and phenol contents, polymeric colour, and antioxidant activity was investigated. Also, reaction rate constant, half-lives of degradation, and activation energy were calculated. Control sample was juice without addition of extracts. The highest anthocyanin content at 30 °C was in samples with the addition of olive leaf and green tea. At 90 °C the highest anthocyanin content was measured in samples with the addition of extract of red wine and bioflavonoides. Samples supplemented with the extracts had much higher antioxidant activity in comparison to the control sample. Results showed that at 90 °C the sample with green tea supplementation had the lowest reaction rate constant and the highest half-life. Activation energy ranged from 29 to 44 kJ molâ1
Anthocyanins, phenols, and antioxidant activity in blackberry juice with plant extracts addition during heating
Lovastatin Protects against Experimental Plague in Mice
Background: Plague is an ectoparasite-borne deadly infection caused by Yersinia pestis, a bacterium classified among the group A bioterrorism agents. Thousands of deaths are reported every year in some African countries. Tetracyclines and cotrimoxazole are used in the secondary prophylaxis of plague in the case of potential exposure to Y. pestis, but cotrimoxazole-resistant isolates have been reported. There is a need for additional prophylactic measures. We aimed to study the effectiveness of lovastatin, a cholesterol-lowering drug known to alleviate the symptoms of sepsis, for plague prophylaxis in an experimental model. Methodology: Lovastatin dissolved in Endolipide was intraperitoneally administered to mice (20 mg/kg) every day for 6 days prior to a Y. pestis Orientalis biotype challenge. Non-challenged, lovastatin-treated and challenged, untreated mice were also used as control groups in the study. Body weight, physical behavior and death were recorded both prior to infection and for 10 days post-infection. Samples of the blood, lungs and spleen were collected from dead mice for direct microbiological examination, histopathology and culture. The potential antibiotic effect of lovastatin was tested on blood agar plates. Conclusions/Significance: Lovastatin had no in-vitro antibiotic effect against Y. pestis. The difference in the mortality between control mice (11/15; 73.5%) and lovastatin-treated mice (3/15; 20%) was significant (P,0.004; Mantel-Haensze
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