Measuring Quality in Chat Reference Consortia: A Comparative Analysis of Responses to Users’ Queries

Academic libraries have experienced growing demand for 24/7 accessto resources and services. Despite the challenges and costs of chatreference service and consortia, many libraries are finding the demandfor these services worth the cost. One key challenge is providing andmeasuring quality of service, particularly in a consortia setting. This studyexplores the quality of service provided in one academic library participatingin a 24/7 chat reference consortium, by assessing transcripts ofchat sessions using in-house reference quality standards. Findings pointto both similarities and differences between chat interactions of locallibrarians versus consortia staff

Monitoring Feeding Tube Placement

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141133/1/ncp0487.pd

The Fabry disease-associated lipid Lyso-Gb3 enhances voltage-gated calcium currents in sensory neurons and causes pain

Fabry disease is an X-linked lysosomal storage disorder characterised by accumulation of glycosphingolipids, and accompanied by clinical manifestations, such as cardiac disorders, renal failure, pain and peripheral neuropathy. Globotriaosylsphingosine (lyso-Gb3), a deacylated form of globotriaosylceramide (Gb3), has emerged as a marker of Fabry disease. We investigated the link between Gb3, lyso-Gb3 and pain. Plantar administration of lyso-Gb3 or Gb3 caused mechanical allodynia in healthy mice. In vitro application of 100nM lyso-Gb3 caused uptake of extracellular calcium in 10% of sensory neurons expressing nociceptor markers, rising to 40% of neurons at 1μM, a concentration that may occur in Fabry disease patients. Peak current densities of voltage-dependent Ca(2+) channels were substantially enhanced by application of 1μM lyso-Gb3. These studies suggest a direct role for lyso-Gb3 in the sensitisation of peripheral nociceptive neurons that may provide an opportunity for therapeutic intervention in the treatment of Fabry disease-associated pain

Comparing PyMorph and SDSS photometry. II. The differences are more than semantics and are not dominated by intracluster light

The Sloan Digital Sky Survey pipeline photometry underestimates the brightnesses of the most luminous galaxies. This is mainly because (i) the SDSS overestimates the sky background and (ii) single or two-component Sersic-based models better fit the surface brightness profile of galaxies, especially at high luminosities, than does the de Vaucouleurs model used by the SDSS pipeline. We use the PyMorph photometric reductions to isolate effect (ii) and show that it is the same in the full sample as in small group environments, and for satellites in the most massive clusters as well. None of these are expected to be significantly affected by intracluster light (ICL). We only see an additional effect for centrals in the most massive halos, but we argue that even this is not dominated by ICL. Hence, for the vast majority of galaxies, the differences between PyMorph and SDSS pipeline photometry cannot be ascribed to the semantics of whether or not one includes the ICL when describing the stellar mass of massive galaxies. Rather, they likely reflect differences in star formation or assembly histories. Failure to account for the SDSS underestimate has significantly biased most previous estimates of the SDSS luminosity and stellar mass functions, and therefore Halo Model estimates of the z ~ 0.1 relation between the mass of a halo and that of the galaxy at its center. We also show that when one studies correlations, at fixed group mass, with a quantity which was not used to define the groups, then selection effects appear. We show why such effects arise, and should not be mistaken for physical effects.Comment: 15 pages, 17 figures, accepted for publication in MNRAS. The PyMorph luminosities and stellar masses are available at https://www.physics.upenn.edu/~ameert/SDSS_PhotDec

The high mass end of the stellar mass function: Dependence on stellar population models and agreement between fits to the light profile

We quantify the systematic effects on the stellar mass function which arise from assumptions about the stellar population, as well as how one fits the light profiles of the most luminous galaxies at z ~ 0.1. When comparing results from the literature, we are careful to separate out these effects. Our analysis shows that while systematics in the estimated comoving number density which arise from different treatments of the stellar population remain of order < 0.5 dex, systematics in photometry are now about 0.1 dex, despite recent claims in the literature. Compared to these more recent analyses, previous work based on Sloan Digital Sky Survey (SDSS) pipeline photometry leads to underestimates of rho_*(> M_*) by factors of 3-10 in the mass range 10^11 - 10^11.6 M_Sun, but up to a factor of 100 at higher stellar masses. This impacts studies which match massive galaxies to dark matter halos. Although systematics which arise from different treatments of the stellar population remain of order < 0.5 dex, our finding that systematics in photometry now amount to only about 0.1 dex in the stellar mass density is a significant improvement with respect to a decade ago. Our results highlight the importance of using the same stellar population and photometric models whenever low and high redshift samples are compared.Comment: 18 pages, 17 figures, accepted for publication in MNRAS. The PyMorph luminosities and stellar masses are available at https://www.physics.upenn.edu/~ameert/SDSS_PhotDec

Configurational entropy of black hole quantum cores

Two types of information entropy are studied for the quantum states of a model for the matter core inside a black hole geometry. A detailed description is first given of the quantum mechanical picture leading to a spectrum of bound states for a collapsing ball of dust in general relativity with a non-trivial ground state. Information entropies are then computed, shedding new light on the stability of the ground state and the spectrum of higher excited states.Comment: 14 pages, 4 figures, improved versio

The Ghosts of Bindings Past: Micro-Computed X-Ray Tomography for the Study of Bookbinding

This essay describes the results of a new application of micro-computed X-ray tomography (µCT) to conduct nondestructive investigations of the binding structures of premodern books. This application addresses a twofold challenge in the study of historic bindings and their construction. Few premodern books survive in their original bindings. Moreover, until recently, when books were rebound, the original structures were rarely documented, and the remains were usually discarded. Where original bindings do remain in situ, much of their structure is, by design, hidden. Particulars of construction may be surmised; but without destructive disbinding, little can be proven. µCT enables an exploratory, multilinear approach to codicological investigations that makes bindings accessible in the form of tractable volumetric data

Heat flow at the Platanares, Honduras, geothermal site

Three boreholes, PLTG-1, PLTG-2 and PLTG-3, were drilled in the Platanares, Honduras geothermal system to evaluate the geothermal energy potential of the site. The maximum reservoir temperature was previously estimated at 225-240[deg]C using various types of chemical and isotopic geothermometry. Geothermal gradients of 139-239[deg]C/km, calculated from two segments of the temperature-depth profile for borehole PLTG-2, were used to project a minimum depth to the geothermal reservoir of 1.2-1.7 km. Borehole PLTG-1 exhibited an erratic temperature distribution attributed to fluid movement through a series of isolated horizontal and subhorizontal fractures. The maximum measured temperature in borehole PLTG-1 was 150.4[deg]C, and in PLTG-2 the maximum measured temperature was 104.3[deg]C. PLTG-3 was drilled after this study and the maximum recorded temperature of 165[deg]C is similar to the temperature encountered in PLTG-1.Heat flow values of 392 mWm-2 and 266 mWm-2 represent the first directly-measured heat flow values for Honduras and northen Central America. Radioactive heat generation, based on gamma-ray analyses of uranium, thorium and potassium in five core samples, is less than 2.0 [mu]Wm-3 and does not appear to be a major source of the high heat flow. Several authors have proposed a variety of extensional tectonic environments for western Honduras and these heat flow values, along with published estimates of heat flow, are supportive of this type of tectonic regime.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/29424/1/0000503.pd