Uniqueness, Epistemic Modals and Dynamic Pronominal Anaphora

While dynamic semantics successfully captures presupposition mechanisms and some uses of anaphoric pronouns, the theory has some lacunas with regards to anaphoric pronouns that seem to refer to a unique individual as well as ones that are preceded by epistemic modals. The general goal of this dissertation is to fill these lacunas and develop an improved dynamic model. After delivering a general introduction to dynamic semantics, we will tackle the first issue of the dynamic model. More specifically, we will address the criticism put forward by philosophers like Robert van Rooij, which deem dynamic predictions for certain uses of indefinite-linked pronominal anaphora to be unsatisfactory. To put it simply, they claim that in some cases anaphoric pronouns seem to refer to unique individuals, yet dynamic semantics does not represent them in that way. In order to solve the problem concerning uniqueness, I propose to interpret certain uses of indefinite-linked pronominal anaphora, that do not require uniqueness constraints, as being subordinated under a covert epistemic must-operator. This modification allows us to syntactically differentiate between cases that require uniqueness constraints and ones that do not. Due to this syntactic difference, I manage to accurately introduce uniqueness constraints into the semantics so that they solely target cases that require them and, therefore, solve the problem. The second lacuna that will be addressed relates to epistemic modals. In dynamic semantics, might- and must-claims do not license pronominal anaphora. However, intuitively, a pronominal anaphora that has a must-claim or a might-claim as its antecedent utterance is completely felicitous. Hence, I attempt to solve this problematic interpretation of indefinite-linked pronominal anaphoras that are subordinated under an epistemic modal. The dynamic interpretation of must-claims and might-claims will be scrutinized and revised, in order to provide an interpretation that licenses pronominal anaphora by allowing modal claims to add discourse referents to the domain of the context

Recent trends in analytical methods to determine new psychoactive substances in hair

New Psychoactive Substances (NPS) belong to several chemical classes, including phenethylamines, piperazines, synthetic cathinones and synthetic cannabinoids. Development and validation of analytical methods for the determination of NPS both in traditional and alternative matrices is of crucial importance to study drug metabolism and to associate consumption to clinical outcomes and eventual intoxication symptoms. Among different biological matrices, hair is the one with the widest time window to investigate drug-related history and demonstrate past intake. The aim of this paper was to overview the trends of the rapidly evolving analytical methods for the determination of NPS in hair and the usefulness of these methods when applied to real cases. A number of rapid and sensitive methods for the determination of NPS in hair matrix has been recently published, most of them using liquid chromatography coupled to mass spectrometry. Hair digestion and subsequent solid phase extraction or liquid-liquid extraction were described as well as extraction in organic solvents. For most of the methods limits of quantification at picogram per milligram hair were obtained. The measured concentrations for most of the NPS in real samples were in the range of picograms of drug per milligram of hair. Interpretation of the results and lack of cut-off values for the discrimination between chronic consumption and occasional use or external contamination are still challenging. Methods for the determination of NPS in hair are continually emerging to include as many NPS as possible due to the great demand for their detection

Massively parallel lattice–Boltzmann codes on large GPU clusters

This paper describes a massively parallel code for a state-of-the art thermal lattice–Boltzmann method. Our code has been carefully optimized for performance on one GPU and to have a good scaling behavior extending to a large number of GPUs. Versions of this code have been already used for large-scale studies of convective turbulence. GPUs are becoming increasingly popular in HPC applications, as they are able to deliver higher performance than traditional processors. Writing efficient programs for large clusters is not an easy task as codes must adapt to increasingly parallel architectures, and the overheads of node-to-node communications must be properly handled. We describe the structure of our code, discussing several key design choices that were guided by theoretical models of performance and experimental benchmarks. We present an extensive set of performance measurements and identify the corresponding main bottlenecks; finally we compare the results of our GPU code with those measured on other currently available high performance processors. Our results are a production-grade code able to deliver a sustained performance of several tens of Tflops as well as a design and optimization methodology that can be used for the development of other high performance applications for computational physics

Heavily-doped Germanium on Silicon with Activated Doping Exceeding 1020 cm−3 as an Alternative to Gold for Mid-infrared Plasmonics

Ge-on-Si has been demonstrated as a platform for Si foundry compatible plasmonics. We use laser thermal annealing to demonstrate activated doping levels >1020 cm-3 which allows most of the 3 to 20 μm mid-infrared sensing window to be covered with enhancements comparable to gold plasmonics

A Computational Tool for the Design of Hybrid Rockets

AbstractA computational tool able to perform a fast analysis of hybrid rocket engines is presented, describing briefly the mathematical and physical models used. Validation of the code is also shown: 16 different static firing tests available in the open literature are used to compare measured operational parameters such as chamber pressure, thrust, and specific impulse with the code's output. The purpose of the program is to perform rapid evaluation and assessment on a possible first design of hybrid rockets, without relying on computationally expensive simulations or onerous experimental tests. The validated program considers as benchmark and study case the design of a liquid-oxygen/paraffin hybrid rocket engine to be used as the upper stage of a small launcher derived from VEGA building blocks. A full-factorial parametric analysis is performed for both pressure-fed and pump-fed systems to find a configuration that delivers the equivalent total impulse of a VEGA-like launcher third and fourth stage as a first evaluation. This parametric analysis is also useful to highlight how the oxidizer injection system, the fuel grain design, and the nozzle features affect the performance of the rocket

Evaluation of T-wave alternans activity under stress conditions after 5 d and 21 d of sedentary head-down bed rest

It is well known that prolonged microgravity leads to cardiovascular deconditioning, inducing significant changes in autonomic control of the cardiovascular system. This may adversely influence cardiac repolarization, and provoke cardiac rhythm disturbances. T-wave alternans (TWA), reflecting temporal and spatial repolarization heterogeneity, could be affected. The aim of this work was to test the hypothesis that 5 d and 21 d head-down (-6°) bed rest (HDBR) increases TWA, thus suggesting a higher underlying electrical instability and related arrhythmogenic risk.Forty-four healthy male volunteers were enrolled in the experiments as part of the European Space Agency's HDBR studies. High-fidelity ECG was recorded during orthostatic tolerance (OT) and aerobic power (AP) tests, before (PRE) and after HDBR (POST). A multilead scheme for TWA amplitude estimation was used, where non-normalized and T-wave amplitude normalized TWA indices were computed. In addition, spectral analysis of heart rate variability during OT was assessed.Both 5 d and 21 d HDBR induced a reduction in orthostatic tolerance time (OTT), as well as a decrease in maximal oxygen uptake and reserve capacity, thus suggesting cardiovascular deconditioning. However, TWA indices were found not to increase. Interestingly, subjects with lower OTT after 5 d HDBR also showed higher TWA during recovery after OT testing, associated with unbalanced sympathovagal response, even before the HDBR. In contrast with previous observations, augmented ventricular heterogeneity related to 5 d and 21 d HDBR was not sufficient to increase TWA under stress conditions

Brown rice and pulses for the development of shelf-stable and low glycemic index ready-to-eat meals

Shelf-stable low glycemic index ready-to-eat (RTE) risotto meals (in pouches) containing brown rice and pulses (recipe A = chickpeas; recipe B = lentils, and beans) were developed, stored for 12-months at room temperature, and characterized over time. RTE meals were heated in microwave (replicating home consumption procedure), and analyzed for in vitro starch digestibility, textural attributes, and consumer acceptability. Digestible starch fractions were similar in the formulations during storage, and in vivo testing demonstrated low glycemic indexes (recipe A = 43.5 ± 6.8; recipe B = 31.8 ± 6.5) for the two meals. Hardness of risotto components increased during storage and microwave heating did not fully recover textural attibutes characteristic of the fresh product. Consumers’ (50) acceptability remained high (>5.5 out of 9) until the end of storage. This study demonstrates brown rice with pulses can be used for developing stable and accepted ready-to-eat meals having low glycemic indexes