174 research outputs found

    Assessing Contemporary Human Activity at Sites in the Anasazi Archeological District, San Juan National Forest: A Quantitative Approach

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    Table of Contents Introduction.............................................................................1 Approach and Method.........................................................................1 Results.....................................................................................................7 Discussion..........................................................................................14 End Notes..........................................................................................17 References Cited ............................................................................1

    Repeating adrenal vein sampling when neither aldosterone/cortisol ratio exceeds peripheral yields a high incidence of aldosterone-producing adenoma

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    Objectives:In primary aldosteronism, adrenal vein sampling (AVS) suggests unilateral aldosterone-producing adenoma (APA) when the aldosterone/cortisol (A/F) ratio is less than or equal to peripheral on one side and at least two times peripheral on the other. When A/F ratios are lower bilaterally than peripheral despite adequate samples (adrenal venous cortisol 3 times peripheral), we recommend repeat AVS. This study aimed to determine the frequency of this occurrence and outcomes in such cases.Methods:We performed a retrospective observational study of all cases of primary aldosteronism undergoing initial AVS over a 34-year period.Results:Initial AVS in 1397 patients returned satisfactory and discriminatory results in 1066 (76.3%) but 37 patients (2.6%) had adequate samples but bilateral A/F ratios no higher than peripheral. Of the 22 of these 37 who agreed to repeat AVS, 10 demonstrated unilateral aldosterone production, and eight of these had unilateral adrenalectomy disclosing APAs and resulting in cure (3) or improvement (5) in hypertension. Eight had bilateral aldosterone production. Four studies were inconclusive. Patients with initial unsatisfactory AVS because of bilaterally low A/F ratios had significantly (P=0.023) more unilateral disease [10 of 18 satisfactory repeat studies (55.6%) vs. 326 of 1066 satisfactory initial studies (30.6%)] and a significantly higher (67.6 vs. 49.9%, P=0.034) percentage of males.Conclusion:As the incidence of APAs was high in a subgroup with low A/F bilaterally on initial AVS, these patients should be offered repeat AVS. This might reflect both a greater dependence of aldosterone production on adrenocorticotrophic hormone (ACTH) in APAs and the pulsatile nature of ACTH secretion

    Single-frame transmission and phase imaging using off-axis holography with undetected photons

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    Imaging with undetected photons relies upon nonlinear interferometry to extract the spatial image from an infrared probe beam and reveal it in the interference pattern of an easier‑to‑detect visible beam. Typically, the transmission and phase images are extracted using phase‑shifting techniques and combining interferograms from multiple frames. Here we show that off‑axis digital holography enables reconstruction of both transmission and phase images at the infrared wavelength from a single interferogram, and hence a single frame, recorded in the visible. This eliminates the need for phase stepping and multiple acquisitions, thereby greatly reducing total measurement time for imaging with long acquisition times at low flux or enabling video‑rate imaging at higher flux. With this single‑frame acquisition technique, we are able to reconstruct transmission images of an object in the infrared beam with a signal‑to‑noise ratio of 3.680 ± 0.004 at 10 frames per second, and record a dynamic scene in the infrared beam at 33 frames per second

    A Review of the Occurrence of Bats (Chiroptera) on Islands in the North East Atlantic and on North Sea Installations

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    The bats recorded from Iceland, the Faroe Islands, the Shetland Islands, the Orkney Islands, and North Sea installations are reviewed to the end of 2012. In total 12 species have been positively identified, while a considerable proportion of all records are sightings of unidentified bats. Eight of the species are European in origin and four originate from the New World. The largest number of species (8) has been recorded in Iceland, but the greatest number of individuals (180) has been found in Orkney. The bat invasion on the Faroe Islands in 2010 is without precedence, when 70 observations of a minimum of 45 individuals were noted. Most bat observations in the study area occurred in the autumn, with fewer in the spring. Most observations were of single animals, but there were also sightings of up to 12 individuals. There has been a marked increase in bat records in the past three decades. We discuss whether this is a real increase, or due to improved communications, increased public awareness, increased shipping, changes in weather patterns and/or the effects of climate change. All factors appear to be involved.© Museum and Institute of Zoology PAS. The attached document is the author(’s’) final accepted/submitted version of the journal article. You are advised to consult the publisher’s version if you wish to cite from it

    Three-dimensional reconstruction of synapses and dendritic spines in the rat and ground squirrel hippocampus: New structural-functional paradigms for synaptic function

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    Published data are reviewed along with our own data on synaptic plasticity and rearrangements of synaptic organelles in the central nervous system. Contemporary laser scanning and confocal microscopy techniques are discussed, along with the use of serial ultrathin sections for in vivo and in vitro studies of dendritic spines, including those addressing relationships between morphological changes and the efficiency of synaptic transmission, especially in conditions of the long-term potentiation model. Different categories of dendritic spines and postsynaptic densities are analyzed, as are the roles of filopodia in originating spines. The role of serial ultrathin sections for unbiased quantitative stereological analysis and three-dimensional reconstruction is assessed. The authors data on the formation of more than two synapses on single mushroom spines on neurons in hippocampal field CA1 are discussed. Analysis of these data provides evidence for new paradigms in both the organization and functioning of synapses

    Aneuploidy and prognosis of non-small-cell lung cancer: a meta-analysis of published data

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    In lung cancer, DNA content abnormalities have been described as a heterogeneous spectrum of impaired tumour cell DNA histogram patterns. They are merged into the common term of aneuploidy and probably reflect a high genotypic instability. In non-small-cell lung cancer, the negative effect of aneuploidy has been a subject of controversy inasmuch as studies aimed at determining the survival–DNA content relationship have reported conflicting results. We made a meta-analysis of published studies aimed at determining the prognostic effect of aneuploidy in surgically resected non-small-cell lung cancer. 35 trials have been identified in the literature. A comprehensive collection of data has been constructed taking into account the following parameters: quality of specimen, DNA content assessment method, aneuploidy definition, histology and stage grouping, quality of surgical resection and demographic characteristics of the analysed population. Among the 4033 assessable patients, 2626 suffered from non-small-cell lung cancer with aneuploid DNA content (overall frequency of aneuploidy: 0.65; 95% CI: (0.64–0.67)). The DerSimonian and Laird method was used to estimate the size effects and the Peto and Yusuf method was used in order to generate the odds ratios (OR) of reduction in risk of death for patients affected by a nearly diploid (non-aneuploid) non-small-cell lung cancer. Survivals following surgical resection, from 1 to 5 years, were chosen as the end-points of our meta-analysis. Patients suffering from a nearly diploid tumour benefited from a significant reduction in risk of death at 1, 2, 3 and 4 years with respective OR: 0.51, 0.51, 0.45 and 0.67 (P< 10−4for each end-point). 5 years after resection, the reduction of death was of lesser magnitude: OR: 0.87 (P = 0.08). The test for overall statistical heterogeneity was conventionally significant (P< 0.01) for all 5 end-points, however. None of the recorded characteristics of the studies could explain this phenomenon precluding a subset analysis. Therefore, the DerSimonian and Laird method was applied inasmuch as this method allows a correction for heterogeneity. This method demonstrated an increase in survival at 1, 2, 3, 4 and 5 years for patients with diploid tumours with respective size effects of 0.11, 0.15, 0.20, 0.20 and 0.21 (value taking into account the correction for heterogeneity;P< 10−4for each end-point). Patients who benefit from a surgical resection for non-small-cell lung cancer with aneuploid DNA content prove to have a higher risk of death. This negative prognostic factor decreases the probability of survival by 11% at one year, a negative effect deteriorating up to 21% at 5 years following surgery. © 2001 Cancer Research Campaign http://www.bjcancer.co
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