Grammar-Based Geodesics in Semantic Networks

A geodesic is the shortest path between two vertices in a connected network. The geodesic is the kernel of various network metrics including radius, diameter, eccentricity, closeness, and betweenness. These metrics are the foundation of much network research and thus, have been studied extensively in the domain of single-relational networks (both in their directed and undirected forms). However, geodesics for single-relational networks do not translate directly to multi-relational, or semantic networks, where vertices are connected to one another by any number of edge labels. Here, a more sophisticated method for calculating a geodesic is necessary. This article presents a technique for calculating geodesics in semantic networks with a focus on semantic networks represented according to the Resource Description Framework (RDF). In this framework, a discrete "walker" utilizes an abstract path description called a grammar to determine which paths to include in its geodesic calculation. The grammar-based model forms a general framework for studying geodesic metrics in semantic networks.Comment: First draft written in 200

An assessment of anxiety levels in dyslexic students in higher education

Background: It has long been hypothesized that children with learning disabilities, including dyslexia, may be highly vulnerable to emotional consequences such as anxiety. However, research has centred on school aged children. Aims: The present study aimed to clarify these findings with dyslexic students in higher education. Samples: 16 students with dyslexia were compared to 16 students with no history of learning difficulties. Methods: Students were asked to complete a verbal questionnaire concerning trait anxiety levels. They were then told that they would be given a timed reading test and their state anxiety levels were measured using the State‐Trait Anxiety Inventory (STAI; Spielberger, Gorsuch, & Lushene, 1983). Finally their reading was assessed using the Test of Word Reading Efficiency (Torgesen, Wagner & Rashotte, 1999). Results: Dyslexic students showed slower reading speeds than controls. They also had higher levels of state anxiety and elevated levels of academic and social, but not appearance anxiety. Conclusions: Dyslexic students in higher education show anxiety levels that are well above what is shown by students without learning difficulties. This anxiety is not limited to academic tasks but extends to many social situations. It is proposed that assessment of emotional well‐being should form part of the assessment of need for dyslexic students entering higher education

Human islet isolation and allotransplantation in 22 consecutive cases

This report provides our initial experience in islet isolation and intrahepatic allotransplantation in 21 patients. In group 1, 10 patients underwent combined liver-islet allotransplantation following upper-abdominal exenteration for cancer. In group 2, 4 patients received a combined liver-islet allograft for cirrhosis and diabetes. One patient had plasma C-peptide >3 pM and was therefore excluded from analysis. In group 3, 7 patients received 8 combined cadaveric kidney-islet grafts (one retransplant) for end-stage renal disease secondary to type 1 diabetes mellitus. The islets were separated by a modification of the automated method for human islet isolation and the preparations were infused into the portal vein. Immunosuppression was with FK506 (group 1) plus steroids (groups 2 and 3). Six patients in group 1 did not require insulin treatment for 5 to > 16 months. In groups 2 and 3 none of the patients became insulin-independent, although decreased insulin requirement and stabilization of diabetes were observed. Our results indicate that rejection is still a major factor limiting the clinical application of islet transplantation in patients with type 1 diabetes mellitus, although other factors such as steroid treatment may contribute to deteriorate islet engraftment and/or function. © 1992 by Williams and Wilkins

Local generalised method of moments: an application to point process-based rainfall models

Long series of simulated rainfall are required at point locations for a range of applications, including hydrological studies. Clustered point process-based rainfall models have been used for generating such simulations for many decades. These models suffer from a major limitation, however, their stationarity. Although seasonality can be allowed by fitting separate models for each calendar month or season, the models are unsuitable in their basic form for climate impact studies. In this paper, we develop new methodology to address this limitation. We extend the current fitting approach by allowing the discrete covariate, calendar month, to be replaced or supplemented with continuous covariates that are more directly related to the incidence and nature of rainfall. The covariate-dependent model parameters are estimated for each time interval using a kernel-based nonparametric approach within a generalised method-of-moments framework. An empirical study demonstrates the new methodology using a time series of 5-min rainfall data. The study considers both local mean and local linear approaches. While asymptotic results are included, the focus is on developing useable methodology for a complex model that can only be solved numerically. Issues including the choice of weighting matrix, estimation of parameter uncertainty and bandwidth and model selection are considered from this perspective

Deformation induced grain rotations in single crystal tantalum

Validation studies of crystal plasticity finite element models typically compare model predictions of strain fields with experimental measurements; often ignored are the grain rotations predicted by the model. Accurate predictions of crystallographic rotations are necessary for trustworthy predictions of strain fields, deformed texture, and failure. This is especially important for body centered cubic (BCC) metals because the exact nature of BCC slip is still under debate [1]. Orientation changes caused by deformation in BCC materials have been predicted by models [2], but little experimental data exists that can confirm or contradict these predictions. To further complicate the situation, there are indications that grain rotations follow different paths in different BCC metals (e.g., Mo and Ta). This study presents experimental measurements of grain rotations in single crystal Ta resulting from quasistatic deformation using multiple techniques. In one set of experiments, single crystal specimens are loaded using an in situ load frame within a scanning electron microscope. Crystallographic rotation is directly observed by repeated EBSD measurements at several load levels. In other experiments, grain orientations (measured by X-ray diffraction and/or EBSD) are compared before and after loading to specific strain levels. Full-field measurements of strain are made during loading to relate orientation changes to local deformation behavior. These grain rotation measurements are compared to predictions from a BCC crystal plasticity model [3] to examine the effects of model choices. Ultimately, these experiment-model comparisons should improve crystal plasticity model predictions of re-orientations and strains, not only for single crystals, but for polycrystals as well. Sandia National Laboratories is a multiprogram laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-AC04-94AL85000. REFERENCES [1] Weinberger, C.R., Boyce, B.L., Battaile, C.C. International Materials Reviews. 2013, 58,296‑314. [2] Weinberger, C.R., Battaile, C.C., Buchheit, T.E., Holm, E.A. Int. J. Plast. 2012, 37, 16‑30. [3] Lim, H., Carroll, J.D., Battaile, C.C., Buchheit, T.E., Boyce, B.L., Weinberger, C.R. Int J.Plast. (in review)

Experiencing the Transition to Remote Teaching and Learning during the COVID-19 Pandemic

The sudden onset of the COVID-19 pandemic severely disrupted universities around the world. In the two weeks following a shelter–in-place order, all the actors of the educational system were forced to transition to remote education. This shift required a new reliance upon technologies that these individuals might never have adopted at all, often with significant difficulties. In this paper, we present a qualitative study on a university-wide survey dataset describing student and faculty experiences of abruptly transitioning to remote teaching and learning during the spring 2020 semester at the Pennsylvania State University. We performed an inductive thematic analysis to identify the challenges and opportunities that arose during the transition. Our findings contribute to building better tools, curriculum, and supports for remote education, particularly during an unexpected crisis

Vibrationally excited HC3N in NGC 4418

We investigate the molecular gas properties of the deeply obscured luminous infrared galaxy NGC 4418. We address the excitation of the complex molecule HC3N to determine whether its unusually luminous emission is related to the nature of the buried nuclear source. We use IRAM 30m and JCMT observations of rotational and vibrational lines of HC3N to model the excitation of the molecule by means of rotational diagrams. We report the first confirmed extragalactic detection of vibrational lines of HC3N. We detect 6 different rotational transitions ranging from J=10-9 to J=30-29 in the ground vibrational state and obtain a tentative detection of the J=38-37 line. We also detect 7 rotational transitions of the vibrationally excited states v6 and v7, with angular momenta ranging from J=10-9 to 28-27. The energies of the upper states of the observed transitions range from 20 to 850 K. In the optically thin regime, we find that the rotational transitions of the vibrational ground state can be fitted for two temperatures, 30 K and 260 K, while the vibrationally excited levels can be fitted for a rotational temperature of 90 K and a vibrational temperature of 500 K. In the inner 300 pc of NGC 4418, we estimate a high HC3N abundance, of the order of 10^-7. The excitation of the HC3N molecule responds strongly to the intense radiation field and the presence of warm, dense gas and dust at the center of NGC 4418. The intense HC3N line emission is a result of both high abundances and excitation. The properties of the HC3N emitting gas are similar to those found for hot cores in Sgr B2, which implies that the nucleus (< 300 pc) of NGC 4418 is reminiscent of a hot core. The potential presence of a compact, hot component (T=500 K) is also discussed

Tacrolimus (FK 506), a Treatment for Primary Sclerosing Cholangitis: Results of an Open‐Label Preliminary Trial

Primary sclerosing cholangitis (PSC) is a chronic inflammatory disease of the liver that is characterized by progressive cholestasis and the development of secondary biliary cirrhosis. There is no widely recognized therapy for this disease, although anti‐inflammatory agents (steroids), immunosuppressive agents (methotrexate), anti‐fihrotics (colchicine), and choleretic agents (ursodeoxycholic acid) have been used in various small series. In the present study, Tacrolimus (FK 506), a new and powerful immunosuppressive macrolide antibiotic, has been used to treat 10 patients with PSC. Each subject had a liver biopsy, ERCP with visualization of the intra‐and extrahepatic biliary tree, and a panel of hcmatological, serological, and biochemical laboratory tests before the initiation of the FK 506 therapy. The FK 506 was administered orally at 12‐h intervals and was monitored by serial plasma FK 506 trough levels. After 360 days of treatment, the median serum bilirubin level was reduced by 75%, and the serum alkaline phosphatase was reduced by 70%. Moreover, the serum ALT and AST levels were reduced by 80 and 86%, respectively. No change in the serum level of BUN and creatinine levels occurred as a consequence of the FK 506 treatment. These data demonstrate that: 1) FK 506 can be used to treat PSC; 2) the response to FK 506 by patients with PSC is rapid; and, 3) no adverse effect on the serum BUN and creatinine levels was observed. It is anticipated that FK 506 will become an important agent for the treatment of patients with PSC because of its powerful immunosuppressive activity. Copyright © 1995, Wiley Blackwell. All rights reserve

Tacrolimus: A Potential New Treatment for Autoimmune Chronic Active Hepatitis: Results of an Open‐Label Preliminary Trial

Autoimmune chronic active hepatitis (CAH‐A) is a chronic liver disease of unknown etiology that is believed to have an autoimmune pathogenesis. The disease is slowly progressive until hepatic failure and portal hypertension develop and either death or liver transplantation occur. Currently, the only widely recognized therapy is the administration of glucocorticoids, which have both anti‐inflammatory and immunosuppressive actions. Many patients cannot tolerate such therapy because of the psychiatric, osteoporotic, and weight‐enhancing actions of steroids. Tacrolimus (FK 506) is a new macrolide antibiotic that has an immunosuppressive activity that is estimated to be 10–200 times greater than that of cyclosporine. Because of its greater immunosuppressive activity, we have used it in the treatment of 21 patients with autoimmune chronic active hepatitis. Before each subject was treated, a liver biopsy and a panel of hematological, serological, and biochemical parameters were assessed. The Tacrolimus was administered orally at 12‐h intervals, and the dose was controlled by monitoring plasma FK trough levels. After 3 months of therapy at an oral dose of 3 mg twice a day, having achieved a median blood level of 0.5 ng/ml, the serum ALT level was reduced by 80%, and the AST level was reduced by 70%. Modest change in the white blood cell count and platelet count were noted. The median BUN level increased from a level of 12 to 18 mg/dl, and the serum creatinine increased from 0.9 to 1.3 mg/dl. These preliminary data demonstrate that: 1) Tacrolimus can be used to successfully treat CAH‐A; 2) the response of CAH‐A to Tacrolimus treatment is rapid and sustained; and 3) a minor increase in the serum BUN and creatinine levels occurs as a consequence of Tacrolimus treatment. It is anticipated that with continued treatment for periods of 1–2 yr, the natural history of CAH‐A will be changed such that hepatic failure and the requirement for liver transplantation may be averted. Copyright © 1995, Wiley Blackwell. All rights reserve