4,546 research outputs found
Vector quantizer designs for joint compression and terrain categorization of multispectral imagery
Two vector quantizer designs for compression of multispectral imagery and their impact on terrain categorization performance are evaluated. The mean-squared error (MSE) and classification performance of the two quantizers are compared, and it is shown that a simple two-stage design minimizing MSE subject to a constraint on classification performance has a significantly better classification performance than a standard MSE-based tree-structured vector quantizer followed by maximum likelihood classification. This improvement in classification performance is obtained with minimal loss in MSE performance. The results show that it is advantageous to tailor compression algorithm designs to the required data exploitation tasks. Applications of joint compression/classification include compression for the archival or transmission of Landsat imagery that is later used for land utility surveys and/or radiometric analysis
Geology of the Peterborough and Concord Quadrangles, New Hampshire
Guidebook for field trips in southwestern New Hampshire, southeastern Vermont, and north-central Massachusetts: New England Intercollegiate Geological Conference, 80th annual meeting, October 14, 15 and 16, 1988, Keene, New Hampshire: Trip C-
Screening for urinary tract colonisation prior to corticosteroid administration in acute multiple sclerosis relapses: Validation of an updated algorithm
INTRODUCTION: To evaluate an updated algorithm in the detection of urinary tract infection (UTI) prior to high-dose corticosteroid treatment in acute relapses in multiple sclerosis (MS). This updated algorithm aimed to decrease the unnecessary use of antibiotics, whilst maintaining accuracy and safety. METHODS: Prospective cohort study of 471 consecutive patients with MS relapses in a hospital-based outpatient acute relapse clinic. 172 patients met exclusion criteria, leaving 299 patients for analysis. Patients underwent urine dipstick and were treated for UTI if 2 or more of: nitrites, leukocyte esterase and cloudy urine were positive. Patients with confirmed acute MS relapse were treated with high dose intravenous or oral methylprednisolone. RESULTS: Significant bacteriuria (>105âŻcolony forming units/mL) was present in 33 (11%, 95% CI 8-15) patients. The algorithm sensitivity and specificity was 24% and 94% respectively; the negative predictive value was 91%. The overall accuracy of the algorithm was 87%. No adverse sequelae were identified in 25 patients who received high dose methylprednisolone in the presence of an untreated UTI. CONCLUSION: With an improved specificity, this updated algorithm addresses previous issues concerning the unnecessary prescription of antibiotics, whilst improving accuracy and maintaining safety
The isolation of upper management
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/30694/1/0000339.pd
Folding and Hydrodynamics of a DNA i-Motif from the c-MYC Promoter Determined by Fluorescent Cytidine Analogs
AbstractThe four-stranded i-motif (iM) conformation of cytosine-rich DNA has importance to a wide variety of biochemical systems that range from their use in nanomaterials to potential roles in oncogene regulation. The iM structure is formed at slightly acidic pH, where hemiprotonation of cytosine results in a stable C-C+ basepair. Here, we performed fundamental studies to examine iM formation from a C-rich strand from the promoter of the human c-MYC gene. We used a number of biophysical techniques to characterize both the hydrodynamic properties and folding kinetics of a folded iM. Our hydrodynamic studies using fluorescence anisotropy decay and analytical ultracentrifugation show that the iM structure has a compact size in solution and displays the rigidity of a double strand. By studying the rates of circular dichroism spectral changes and quenching of fluorescent cytidine analogs, we also established a mechanism for the folding of a random coil oligo into the iM. In the course of determining this folding pathway, we established that the fluorescent dC analogs tC° and PdC can be used to monitor individual residues of an iM structure and to determine the pKa of an iM. We established that the C-C+ hydrogen bonding of certain bases initiates the folding of the iM structure. We also showed that substitutions in the loop regions of iMs give a distinctly different kinetic signature during folding compared with bases that are intercalated. Our data reveal that the iM passes through a distinct intermediate form between the unfolded and folded forms. Taken together, our results lay the foundation for using fluorescent dC analogs to follow structural changes during iM formation. Our technique may also be useful for examining folding and structural changes in more complex iMs
Ulcerative Colitis Physician Team-Work in the Treatment
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68011/2/10.1177_000992286400300203.pd
Co-Eruptive Tremor from Bogoslof Volcano: Seismic Wavefield Composition at Regional Distances
We analyze seismic tremor recorded during eruptive activity over the course of the 2016â2017 eruption of Bogoslof volcano, Alaska. Only regional recordings of the tremor wavefield exist for Bogoslof, making it a challenge to place the recordings in context with other eruptions that are normally captured by local seismic data. We apply a technique of time-frequency polarization analysis to three-component seismic data to reveal the wavefield composition of Bogoslof eruption tremor.We find that at regional distances, the tremor is dominated by P-waves in the band from 1.5 to 10 Hz. Using this information, along with an enriched Bogoslof earthquake catalog, we obtain estimates of average reduced displacement (DR) for eruption tremor during 25 of the 70 Bogoslof events. DR reaches as high as approximately 40 cm2 for two of the major events, similar to other VEI~3 eruptions in Alaska. Overall, average reduced displacement displays a weak correlation to plume height during the first half of the 9-month-long eruption sequence, with a few notable exceptions. The two events with the highest DR values also generated measurable eruption tremor at very-long-periods (VLP) between 0.05 and 0.15 Hz
Reviews: Act Naturally
Bethany Easton, Lecturer in Project Management, University of Cumbria, reviews the book 'Act Naturally: The Beatles on Film' by Steve Matteo (Lanham, MD: Rowman and Littlefield, 2023 ISBN: 9781493059010, 350 pp.).
With an impressive and ever-expanding number of films on the Beatles, it is only natural that authors are producing texts that examine this particular element of the groupâs history. Steve Matteo delves into this area in Act Naturally: The Beatles on Film, in which he explores the Beatlesâ various escapades in the film world, from A Hard Dayâs Night (dir. Richard Lester, 1964) to Peter Jacksonâs (2021) The Beatles: Get Back. Matteo details his aim from the outset: to offer Beatles fans an engaging but informative text exploring the Beatles on film through a mix of images, description and fact. Each chapter details exact dates, locations and events: "April 7th featured shooting the pub cellar sequence where Ringo is confronted by Raja the Bengal tiger, who turns into a pussycat whenever he hears the fourth movement of Beethovenâs Ninth Symphony, commonly known as âOde to Joyâ. (138)". Although Matteo self-describes as not being âa film scholarâ (vi), his work indicates the contrary, as he presents his meticulously researched findings throughout. This level of detail goes beyond solely exploring the Beatles. There is an enormous amount of historical cinematic context that preceded and surrounded the groupâs film work, including the ânew British film wave: realist films, social problem films, and what came to be known as âkitchen sinkâ filmsâ (11). As the author notes, âThis book is as much a celebration of the films of the Beatles, as it is a championing of the British films of the 1960s in generalâ (vi)
Dose-escalation study of a second-generation non-ansamycin HSP90 inhibitor, onalespib (AT13387), in combination with imatinib in patients with metastatic gastrointestinal stromal tumour
AbstractBackgroundGastrointestinal stromal tumours (GIST) treated with the tyrosine kinase inhibitor (TKI) imatinib can become resistant when additional mutations in the receptor tyrosine kinases KIT or PDGFRA block imatinib activity. Mutated KIT requires the molecular chaperone heat-shock protein 90 (HSP90) to maintain stability and activity. Onalespib (AT13387) is a potent non-ansamycin HSP90 inhibitor. We hypothesised that the combination of onalespib and imatinib may be safe and effective in managing TKI-resistant GIST.Patients and methodsIn this dose-escalation study, we evaluated the safety and efficacy of combination once-weekly intravenous onalespib for 3 weeks and daily oral imatinib in 28-d cycles. Twenty-six patients with TKI-resistant GIST were enrolled into four sequential dose cohorts of onalespib (dose range, 150â220Â mg/m2) and imatinib 400Â mg. The relationship between tumour mutational status (KIT/PDGFRA) and efficacy of treatment was explored.ResultsCommon onalespib-related adverse events were diarrhoea (58%), nausea (50%), injection site events (46%), vomiting (39%), fatigue (27%), and muscle spasms (23%). Overall, 81% of patients reported more than one onalespib-related gastrointestinal disorder. Nine patients (35%) had a best response of stable disease, including two patients who had KIT mutations known to be associated with resistance to imatinib and sunitinib. Disease control at 4 months was achieved in five patients (19%), and median progression-free survival was 112 d (95% confidence interval 43â165). One patient with PDGFRA-mutant GIST had a partial response for more than 376 d.ConclusionThe combination of onalespib plus imatinib was well tolerated but exhibited limited antitumour activity as dosed in this TKI-resistant GIST patient population.Trial registration ID: clinicaltrials.gov: NCT0129420
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