4,210 research outputs found

    Aerosol single-scattering albedo and asymmetry parameter from MFRSR observations during the ARM Aerosol IOP 2003

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    International audienceMulti-filter Rotating Shadowband Radiometers (MFRSRs) provide routine measurements of the aerosol optical depth (?) at six wavelengths (0.415, 0.5, 0.615, 0.673, 0.870 and 0.94 ?m). The single-scattering albedo (?0) is typically estimated from the MFRSR measurements by assuming the asymmetry parameter (g). In most instances, however, it is not easy to set an appropriate value of g due to its strong temporal and spatial variability. Here, we introduce and validate an updated version of our retrieval technique that allows one to estimate simultaneously ?0 and g for different types of aerosol. We use the aerosol and radiative properties obtained during the Atmospheric Radiation Measurement (ARM) Program's Aerosol Intensive Operational Period (IOP) to validate our retrieval in two ways. First, the MFRSR-retrieved optical properties are compared with those obtained from independent surface, Aerosol Robotic Network (AERONET), and aircraft measurements. The MFRSR-retrieved optical properties are in reasonable agreement with these independent measurements. Second, we perform radiative closure experiments using the MFRSR-retrieved optical properties. The calculated broadband values of the direct and diffuse fluxes are comparable (~5 W/m2) to those obtained from measurements

    THE CHOICE OF A SURVIVING SIBLING AS ā€œSCAPEGOATā€ IN SOME CASES OF MATERNAL BEREAVEMENTā€”A CASE REPORT

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    ā€” This paper presents a description of a pathological variation of the mourning process in mothers who have suffered a narcissistically damaging psychological or actual loss of a child. A surviving sibling chosen as a displacement object for the mother's sense of guilt and self-hatred. The parent-child estrangement continues for years after the trauma with an extremity and severity that often necessitates court intervention. A case illustration is presented and a concluding suggestion that counseling by available professionals at the time of the bereavement would be both economical and effective in forestalling this variety of pathological family scapegoating.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73748/1/j.1469-7610.1975.tb00367.x.pd

    Beyond Outerplanarity

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    We study straight-line drawings of graphs where the vertices are placed in convex position in the plane, i.e., convex drawings. We consider two families of graph classes with nice convex drawings: outer kk-planar graphs, where each edge is crossed by at most kk other edges; and, outer kk-quasi-planar graphs where no kk edges can mutually cross. We show that the outer kk-planar graphs are (āŒŠ4k+1āŒ‹+1)(\lfloor\sqrt{4k+1}\rfloor+1)-degenerate, and consequently that every outer kk-planar graph can be (āŒŠ4k+1āŒ‹+2)(\lfloor\sqrt{4k+1}\rfloor+2)-colored, and this bound is tight. We further show that every outer kk-planar graph has a balanced separator of size O(k)O(k). This implies that every outer kk-planar graph has treewidth O(k)O(k). For fixed kk, these small balanced separators allow us to obtain a simple quasi-polynomial time algorithm to test whether a given graph is outer kk-planar, i.e., none of these recognition problems are NP-complete unless ETH fails. For the outer kk-quasi-planar graphs we prove that, unlike other beyond-planar graph classes, every edge-maximal nn-vertex outer kk-quasi planar graph has the same number of edges, namely 2(kāˆ’1)nāˆ’(2kāˆ’12)2(k-1)n - \binom{2k-1}{2}. We also construct planar 3-trees that are not outer 33-quasi-planar. Finally, we restrict outer kk-planar and outer kk-quasi-planar drawings to \emph{closed} drawings, where the vertex sequence on the boundary is a cycle in the graph. For each kk, we express closed outer kk-planarity and \emph{closed outer kk-quasi-planarity} in extended monadic second-order logic. Thus, closed outer kk-planarity is linear-time testable by Courcelle's Theorem.Comment: Appears in the Proceedings of the 25th International Symposium on Graph Drawing and Network Visualization (GD 2017

    The mechanism of twin thickening and the elastic strain state of TWIP steel nanotwins

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    A Twinning Induced Plasticity (TWIP) steel with a nominal composition of Fe-16.4Mn-0.9C-0.5Si-0.05Nb-0.05V was deformed to an engineering strain of 6\%. The strain around the deformation twins were mapped using the 4D-STEM technique. Strain mapping showed a large average elastic strain of approximately 6\% in the directions parallel and perpendicular to the twinning direction. However, the large average strain comprised of several hot spots of even larger strains of up to 12\%. These hot spots could be attributed to a high density of sessile Frank dislocations on the twin boundary and correspond to shear stresses of 1--1.5 GPa. The strain and therefore stress fields are significantly larger than other materials known to twin and are speculated to be responsible for the early thickness saturation of TWIP steel nanotwins. The ability to keep twins extremely thin helps improve grain fragmentation, \textit{i.e.} the dynamic Hall-Petch effect, and underpins the large elongations and strain hardening rates in TWIP steels

    Informing wetland management with waterfowl movement and sanctuary use responses to human-induced disturbance

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    Long-term environmental management to prevent waterfowl population declines is informed by ecology, movement behavior and habitat use patterns. Extrinsic factors, such as human-induced disturbance, can cause behavioral changes which may influence movement and resource needs, driving variation that affects management efficacy. To better understand the relationship between human-based disturbance and animal movement and habitat use, and their potential effects on management, we GPS tracked 15 dabbling ducks in California over ~4-weeks before, during and after the start of a recreational hunting season in October/November 2018. We recorded locations at 2-min intervals across three separate 24-h tracking phases: Phase 1) two weeks before the start of the hunting season (control (undisturbed) movement); Phase 2) the hunting season opening weekend; and Phase 3) a hunting weekend two weeks after opening weekend. We used GLMM models to analyze variation in movement and habitat use under hunting pressure compared with ā€˜normalā€™ observed patterns prior to commencement of hunting. We also compared responses to differing levels of disturbance related to the time of day (high - shooting/~daytime); moderate - non-lethal (~crepuscular); and low - night). During opening weekend flight (% time and distance) more than doubled during moderate and low disturbance and increased by ~50% during high disturbance compared with the pre-season weekend. Sanctuary use tripled during moderate and low disturbance and increased ~50% during high disturbance. Two weeks later flight decreased in all disturbance levels but was only less than the pre-season levels during high disturbance. In contrast, sanctuary use only decreased at night, although not to pre-season levels, while daytime doubled from ~45% to \u3e80%. Birds adjust rapidly to disturbance and our results have implications for energetics models that estimate population food requirements. Management would benefit from reassessing the juxtaposition of essential sanctuary and feeding habitats to optimize wetland management for waterfowl

    Myofascial urinary frequency syndrome is a novel syndrome of bothersome lower urinary tract symptoms associated with myofascial pelvic floor dysfunction

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    This study describes a novel, distinct phenotype of urinary symptoms named myofascial urinary frequency syndrome (MUFS) present in one-third of individuals presenting with urinary frequency. In addition to a characteristic symptom constellation suggestive of myofascial dysfunction, MUFS subjects exhibit persistency : a persistent feeling of needing to urinate regardless of urine volume. On examination, 97% of MUFS patients demonstrated pelvic floor hypertonicity with either global tenderness or myofascial trigger points, and 92% displayed evidence of impaired muscular relaxation, hallmarks of myofascial dysfunction. To confirm this symptom pattern was attributable to the pelvic floor musculature, we confirmed the presence of persistency in 68 patients with pelvic floor myofascial dysfunction established through comprehensive examination and electromyography and corroborated by improvement with pelvic floor myofascial release. These symptoms distinguish subjects with myofascial dysfunction from subjects with OAB, IC/BPS, and asymptomatic controls, confirming MUFS is a distinct LUTS symptom complex

    Divergence between genes but limited allelic polymorphism in two MHC class II A genes in Leachā€™s storm-petrels Oceanodroma leucorhoa

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    The major histocompatibility complex (MHC) is critical to host-pathogen interactions. Class II MHC is a heterodimer, with Ī± and Ī² subunits encoded by different genes. The peptide-binding groove is formed by the first domain of both subunits (Ī±1 and Ī²1), but studies of class II variation or natural selection focus primarily on the Ī² subunit and II B genes. We explored MHC II A in Leachā€™s storm-petrel, a seabird with two expressed, polymorphic II B genes. We found two II A genes, Ocle-DAA and Ocle-DBA, in contrast to the single II A gene in chicken and duck. In exon 2 which encodes the Ī±1 domain, the storm-petrel II A genes differed strongly from each other but showed little within-gene polymorphism in 30 individuals: just one Ocle-DAA allele, and three Ocle-DBA alleles differing from each other by single non-synonymous substitutions. In a comparable sample, the two II B genes had nine markedly diverged alleles each. Differences between the Ī±1 domains of Ocle-DAA and Ocle-DBA showed signatures of positive selection, but mainly at non-peptide-binding site (PBS) positions. In contrast, positive selection within and between the II B genes corresponded to putative PBS codons. Phylogenetic analysis of the conserved Ī±2 domain did not reveal deep or well-supported lineages of II A genes in birds, in contrast to the pronounced differentiation of DQA, DPA, and DRA isotypes in mammals. This uncertain homology complicates efforts to compare levels of functional variation and modes of evolution of II A genes across taxa
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