Redeveloping a CLEAN Deconvolution Algorithm for Scatter-Broadened Radio Pulsar Signals

Broadband radio waves emitted from pulsars are distorted and delayed as they propagate toward the Earth due to interactions with the free electrons that compose the interstellar medium, with lower radio frequencies being more impacted than higher frequencies. Multipath propagation in the interstellar medium results in both later times of arrival for the lower frequencies and causes the observed pulse to arrive with a broadened tail described via the pulse broadening function. We employ the CLEAN deconvolution technique to recover both the intrinsic pulse shape and pulse broadening function. This work expands upon previous descriptions of CLEAN deconvolution used in pulse broadening analyses by parameterizing the efficacy on simulated data and developing a suite of tests to establish which of a set of figures of merit lead to an automatic and consistent determination of the scattering timescale and its uncertainty. We compare our algorithm to simulations performed on cyclic spectroscopy estimates of the scattering timescale. We test our improved algorithm on the highly scattered millisecond pulsar J1903+0327, showing the scattering timescale to change over years, consistent with estimates of the refractive timescale of the pulsar

The $94 Billion Problem: Application of Safe Acid Technology (SAT) to Combat Biofilm Infections

Purpose: Biofilm infections present a major public health threat. In the U.S. alone, biofilm infections are implicated in up to 550,000 yearly fatalities with an estimated annual cost of $94 billion. Biofilm infections are difficult to treat, as biofilm-secreting bacteria are highly resistant to host immune responses. We hypothesize that Safe Acid Technology (SAT), a unique acid formulation, may reduce the risk of biofilm infections while maximizing patient safety. Methods: SAT anti-biofilm testing was administered by the Montana State University Center for BioFilm Engineering using a single species (Pseudomonas aeruginosa) biofilm grown in the CDC reactor according to ASTM E2871-12 on polycarbonate coupons. After establishing biofilms, the polycarbonate coupons were exposed to SAT formulations at multiple exposure times in varied concentrations. Results:Log reductions of biofilm ranged from 3.61 at concentrations of C50 to 4.82 at C25. This was compared to biofilm concentration of Log 8.62 on control coupons. Conclusion: The current recommended treatment for biofilm infection involves long-term antibiotic therapy, which may reduce bacteria in the perioperative period but has limited ability to address bacterial resistance and penetrate biofilms. Safe Acid Technology, which demonstrates potent anti-biofilm action along with non-toxicity to human mucosa, may prove a superior and cost-effective alternative to the current treatment paradigm for biofilm infections

Treebank-based acquisition of a Chinese lexical-functional grammar

Scaling wide-coverage, constraint-based grammars such as Lexical-Functional Grammars (LFG) (Kaplan and Bresnan, 1982; Bresnan, 2001) or Head-Driven Phrase Structure Grammars (HPSG) (Pollard and Sag, 1994) from fragments to naturally occurring unrestricted text is knowledge-intensive, time-consuming and (often prohibitively) expensive. A number of researchers have recently presented methods to automatically acquire wide-coverage, probabilistic constraint-based grammatical resources from treebanks (Cahill et al., 2002, Cahill et al., 2003; Cahill et al., 2004; Miyao et al., 2003; Miyao et al., 2004; Hockenmaier and Steedman, 2002; Hockenmaier, 2003), addressing the knowledge acquisition bottleneck in constraint-based grammar development. Research to date has concentrated on English and German. In this paper we report on an experiment to induce wide-coverage, probabilistic LFG grammatical and lexical resources for Chinese from the Penn Chinese Treebank (CTB) (Xue et al., 2002) based on an automatic f-structure annotation algorithm. Currently 96.751% of the CTB trees receive a single, covering and connected f-structure, 0.112% do not receive an f-structure due to feature clashes, while 3.137% are associated with multiple f-structure fragments. From the f-structure-annotated CTB we extract a total of 12975 lexical entries with 20 distinct subcategorisation frame types. Of these 3436 are verbal entries with a total of 11 different frame types. We extract a number of PCFG-based LFG approximations. Currently our best automatically induced grammars achieve an f-score of 81.57% against the trees in unseen articles 301-325; 86.06% f-score (all grammatical functions) and 73.98% (preds-only) against the dependencies derived from the f-structures automatically generated for the original trees in 301-325 and 82.79% (all grammatical functions) and 67.74% (preds-only) against the dependencies derived from the manually annotated gold-standard f-structures for 50 trees randomly selected from articles 301-325

Strategic planning in arts education programme : the case Of Asia art archive in Hong Kong

published_or_final_versionMedia, Culture and Creative CitiesMasterMaster of Social Sciences in Media, Culture and Creative Citie

Social Aggregation in Pea Aphids: Experiment and Random Walk Modeling

From bird flocks to fish schools and ungulate herds to insect swarms, social biological aggregations are found across the natural world. An ongoing challenge in the mathematical modeling of aggregations is to strengthen the connection between models and biological data by quantifying the rules that individuals follow. We model aggregation of the pea aphid, Acyrthosiphon pisum. Specifically, we conduct experiments to track the motion of aphids walking in a featureless circular arena in order to deduce individual-level rules. We observe that each aphid transitions stochastically between a moving and a stationary state. Moving aphids follow a correlated random walk. The probabilities of motion state transitions, as well as the random walk parameters, depend strongly on distance to an aphid\u27s nearest neighbor. For large nearest neighbor distances, when an aphid is essentially isolated, its motion is ballistic with aphids moving faster, turning less, and being less likely to stop. In contrast, for short nearest neighbor distances, aphids move more slowly, turn more, and are more likely to become stationary; this behavior constitutes an aggregation mechanism. From the experimental data, we estimate the state transition probabilities and correlated random walk parameters as a function of nearest neighbor distance. With the individual-level model established, we assess whether it reproduces the macroscopic patterns of movement at the group level. To do so, we consider three distributions, namely distance to nearest neighbor, angle to nearest neighbor, and percentage of population moving at any given time. For each of these three distributions, we compare our experimental data to the output of numerical simulations of our nearest neighbor model, and of a control model in which aphids do not interact socially. Our stochastic, social nearest neighbor model reproduces salient features of the experimental data that are not captured by the control

Treebank-Based Acquisition of a Chinese Lexical-Functional Grammar

Scaling wide-coverage, constraint-based grammars such as Lexical-Functional Grammars (LFG) (Kaplan and Bresnan, 1982; Bresnan, 2001) or Head-Driven Phrase Structure Grammars (HPSG) (Pollard and Sag, 1994) from fragments to naturally occurring unrestricted text is knowledge-intensive, time-consuming and (often prohibitively) expensive. A number of researchers have recently presented methods to automatically acquire wide-coverage, probabilistic constraint-based grammatical resources from treebanks (Cahill et al., 2002, Cahill et al., 2003; Cahill et al., 2004; Miyao et al., 2003; Miyao et al., 2004; Hockenmaier and Steedman, 2002; Hockenmaier, 2003), addressing the knowledge acquisition bottleneck in constraint-based grammar development. Research to date has concentrated on English and German. In this paper we report on an experiment to induce wide-coverage, probabilistic LFG grammatical and lexical resources for Chinese from the Penn Chinese Treebank (CTB) (Xue et al., 2002) based on an automatic f-structure annotation algorithm. Currently 96.751% of the CTB trees receive a single, covering and connected f-structure, 0.112% do not receive an fstructure due to feature clashes, while 3.137% are associated with multiple f-structure fragments. From the f-structure-annotated CTB we extract a total of 12975 lexical entries with 20 distinct subcategorisation frame types. Of these 3436 are verbal entries with a total of 11 different frame types. We extract a number of PCFG-based LFG approximations. Currently our best automatically induced grammars achieve an f-score of 81.57% against the trees in unseen articles 301-325; 86.06% f-score (all grammatical functions) and 73.98% (preds-only) against the dependencies derived from the f-structures automatically generated for the original trees in 301-325 and 82.79% (all grammatical functions) and 67.74% (preds-only) against the dependencies derived from the manually annotated gold-standard f-structures for 50 trees randomly selected from articles 301-325

Engineered FGF1 and FGF2 compositions and methods of use thereof

Engineered FGF1 and FGF2 polypeptides, polynucleotides encoding these polypeptides and DNA constructs, vectors and compositions including these engineered polypeptides are provided herein. The engineered FGF1 and FGF2 polypeptides are more stable than their wild-type counterparts and may be more effective at treating a variety of conditions that FGF1 and FGF2 are useful for treating such as wound healing

Estudio del efecto de la sequía inducida por polietilenglicol en Capsicum frutescens en un sistema hidropónico

La sequía es el factor más común que limita el desarrollo y productividad de los cultivos, afectando severamente a la agricultura. En México, uno de los cultivos de importancia económica y gastronómica sensible al estrés hídrico es el género Capsicum. En el presente estudio se evaluó la aplicación de prolina en plantas de Capsicum frutescens expuestas a sequía inducida por polietilenglicol (PEG) en un sistema hidropónico. Empleando un diseño factorial 22, se evaluaron un total de 60 plántulas durante 120 h dividas en cuatro tratamientos: PEG (0 y 10 %) y Pro (0 y 10 mM) como variables de estudio. Los resultados demostraron que la exposición a 10 mM de Pro indujo un aumento significativo en la concentración de clorofila y de prolina endógena (hoja y raíz) en las plántulas en ausencia de estrés. Además, se observó un 80 % de supervivencia de las plántulas y un aumento en el contenido de prolina en aquellas que estuvieron expuestas a 10 mM Pro + 10 % PEG. De igual manera, se presentó un aumento en el contenido de clorofila (13 µg • mL-1), contenido relativo de agua (CRA) en raíz (77.6 %), porcentaje de electrolitos en hoja y raíz (~44 y ~52 % respectivamente), en comparación con el tratamiento de 0 mM Pro + 10 % PEG. Los resultados sugieren que la aplicación previa de prolina tiene un efecto positivo en la supervivencia de las plántulas bajo condiciones de sequía inducida por PEG

Economic evaluation of population-based type 2 diabetes mellitus screening at different healthcare settings in Vietnam

Introduction: Few economic evaluations have assessed the cost-effectiveness of screening type-2 diabetes mellitus (T2DM) in different healthcare settings. This study aims to evaluate the value for money of various T2DM screening strategies in Vietnam. Methods: A decision analytical model was constructed to compare costs and quality-adjusted life years (QALYs) of T2DM screening in different health care settings, including (1) screening at commune health station (CHS) and (2) screening at district health center (DHC), with no screening as the current practice. We further explored the costs and QALYs of different initial screening ages and different screening intervals. Cost and utility data were obtained by primary data collection in Vietnam. Incremental cost-effectiveness ratios were calculated from societal and payer perspectives, while uncertainty analysis was performed to explore parameter uncertainties. Results: Annual T2DM screening at either CHS or DHC was cost-effective in Vietnam, from both societal and payer perspectives. Annual screening at CHS was found as the best screening strategy in terms of value for money. From a societal perspective, annual screening at CHS from initial age of 40 years was associated with 0.40 QALYs gained while saving US$ 186.21. Meanwhile, one-off screening was not cost-effective when screening for people younger than 35 years old at both CHS and DHC. Conclusions: T2DM screening should be included in the Vietnamese health benefits package, and annual screening at either CHS or DHC is recommended