Mexitl: Multimedia in Executable Interval Temporal Logic

This paper explores a formalism for describing a wide class of multimedia document constraints, based on an interval temporal logic. We describe the requirements that arise from the multimedia documents application area, and we illustrate these requirements using several examples. Then we present the temporal logic formalism that we use. This logic extends existing interval temporal logic with a number of new features: actions, framing of actions, past operators, a projection-like operator called filter and a new handling of interval length. The notation is applied to the specification of the examples, and in particular a set of logical manipulations, providing feedback to an author, is presented. A model theory, logic and satisfaction relation are defined for the notation.     

Wedged multilayer Laue lens

A multilayer Laue lens (MLL) is an x-ray focusing optic fabricated from a multilayer structure consisting of thousands of layers of two different materials produced by thin-film deposition. The sequence of layer thicknesses is controlled to satisfy the Fresnel zone plate law and the multilayer is sectioned to form the optic. An improved MLL geometry can be created by growing each layer with an in-plane thickness gradient to form a wedge, so that every interface makes the correct angle with the incident beam for symmetric Bragg diffraction. The ultimate hard x-ray focusing performance of a wedged MLL has been predicted to be significantly better than that of a nonwedged MLL, giving subnanometer resolution with high efficiency. Here, we describe a method to deposit the multilayer structure needed for an ideal wedged MLL and report our initial deposition results to produce these structures.     

Gastric pacing improves emptying and symptoms in patients with gastroparesis

BACKGROUND & AIMS: No effective treatment is available for patients with gastroparesis refractory to standard medical therapy. The aim of this study was to investigate the effects of gastric pacing on gastric electrical activity, gastric emptying, and symptoms in patients with gastroparesis. METHODS: Nine patients with gastroparesis participated in this study. Four pairs of cardiac pacing wires were implanted on the serosa of the stomach. The protocol consisted of two portions: a temporary inpatient study period and an outpatient study for a period of 1 month or more. RESULTS: Gastric pacing entrained the gastric slow wave in all subjects and converted tachygastria in 2 patients into regular 3-cpm slow waves. Gastric emptying was significantly improved after the outpatient treatment with gastric pacing. The gastric retention at 2 hours was reduced from 77.0% +/- 3.3% to 56.6% +/- 8.6% (P < 0.05). Symptoms of gastroparesis were substantially reduced at the end of the outpatient treatment (1.51 +/- 0.46 vs. 2.84 +/- 0.61; P < 0.04). Eight of 9 patients no longer relied on jejunostomy tube feeding, and no adverse events were noted related to the pacing unit. CONCLUSIONS: Gastric pacing seems to be able to improve symptoms of gastroparesis and to accelerate gastric emptying in patients with gastroparesis. More controlled studies are necessary to further investigate the role of gastric pacing in clinical practice.     

Ultrahigh Energy Absorption Multifunctional Spinodal Nanoarchitectures

Nanolattices are promoted as next‐generation multifunctional high‐performance materials, but their mechanical response is limited to extreme strength yet brittleness, or extreme deformability but low strength and stiffness. Ideal impact protection systems require high‐stress plateaus over long deformation ranges to maximize energy absorption. Here, glassy carbon nanospinodals, i.e., nanoarchitectures with spinodal shell topology, combining ultrahigh energy absorption and exceptional strength and stiffness at low weight are presented. Noncatastrophic deformation up to 80% strain, and energy absorption up to one order of magnitude higher than for other nano‐, micro‐, macro‐architectures and solids, and state‐of‐the‐art impact protection structures are shown. At the same time, the strength and stiffness are on par with the most advanced yet brittle nanolattices, demonstrating true multifunctionality. Finite element simulations show that optimized shell thickness‐to‐curvature‐radius ratios suppress catastrophic failure by impeding propagation of dangerously oriented cracks. In contrast to most micro‐ and nano‐architected materials, spinodal architectures may be easily manufacturable on an industrial scale, and may become the next generation of superior cellular materials for structural applications.     

A Novel Mouse Model of TGFβ2-Induced Ocular Hypertension Using Lentiviral Gene Delivery

Glaucoma is a multifactorial disease leading to irreversible blindness. Primary open-angle glaucoma (POAG) is the most common form and is associated with the elevation of intraocular pressure (IOP). Reduced aqueous humor (AH) outflow due to trabecular meshwork (TM) dysfunction is responsible for IOP elevation in POAG. Extracellular matrix (ECM) accumulation, actin cytoskeletal reorganization, and stiffening of the TM are associated with increased outflow resistance. Transforming growth factor (TGF) β2, a profibrotic cytokine, is known to play an important role in the development of ocular hypertension (OHT) in POAG. An appropriate mouse model is critical in understanding the underlying molecular mechanism of TGFβ2-induced OHT. To achieve this, TM can be targeted with recombinant viral vectors to express a gene of interest. Lentiviruses (LV) are known for their tropism towards TM with stable transgene expression and low immunogenicity. We, therefore, developed a novel mouse model of IOP elevation using LV gene transfer of active human TGFβ2 in the TM. We developed an LV vector-encoding active hTGFβ2^C226,228S under the control of a cytomegalovirus (CMV) promoter. Adult C57BL/6J mice were injected intravitreally with LV expressing null or hTGFβ2^C226,228S. We observed a significant increase in IOP 3 weeks post-injection compared to control eyes with an average delta change of 3.3 mmHg. IOP stayed elevated up to 7 weeks post-injection, which correlated with a significant drop in the AH outflow facility (40.36%). Increased expression of active TGFβ2 was observed in both AH and anterior segment samples of injected mice. The morphological assessment of the mouse TM region via hematoxylin and eosin (H&E) staining and direct ophthalmoscopy examination revealed no visible signs of inflammation or other ocular abnormalities in the injected eyes. Furthermore, transduction of primary human TM cells with LV_hTGFβ2^C226,228S exhibited alterations in actin cytoskeleton structures, including the formation of F-actin stress fibers and crossed-linked actin networks (CLANs), which are signature arrangements of actin cytoskeleton observed in the stiffer fibrotic-like TM. Our study demonstrated a mouse model of sustained IOP elevation via lentiviral gene delivery of active hTGFβ2^C226,228S that induces TM dysfunction and outflow resistance.     

Design of problem-based learning activities in the field of microfluidics for 12- to 13-year-old participants—Small Plumbing!: empowering the next generation of microfluidic engineers

Public engagement activities based on microfluidics are being increasingly delivered and reported on in the literature. Here, we evaluate the success of a novel approach to microfluidics outreach recently undertaken with schoolchildren aged 12–13. Unlike previous work, a problem-based learning approach was adopted whereby participants were asked to design and test a microfluidic system to solve a research challenge. Our aim was to develop understanding of microfluidics design, manufacture and operation via involvement in the full engineering cycle of a product, from ideas to design, and from fabrication to test. This article demonstrates that problem-based learning is a successful method of public engagement with microfluidics, and we share our best practice, including activity design, supporting material produced for the project and an example case study detailing the types of chips produced by the participants. Furthermore, following an evaluation of the activity by all participants recommendations for delivery of this, or similar, activities are provided.     

Supportive Housing: Justifiable Paternalism?

Scholars have long draw on neoliberalism and paternalism as theoretical frameworks to argue that states have become less generous in providing welfare and housing resources. These theories similarly demonstrate that the resources that are provided are characterized by conditional exchanges, whereby welfare recipients and social housing tenants are required to comply with behavioural conditions. Theoretical critiques of state intervention influenced by neoliberalism and paternalism are broad, but they generally agree that conditional welfare approaches, including social housing, focus on changing individuals living in poverty themselves and not sufficiently changing policy, economic, social and institutional forces that underpin poverty. In light of these theories of state intervention, this article draws on an Australian qualitative study with tenants and service providers in supportive housing. The article shows that supportive housing is positioned as a significant intervention to not only house disadvantaged groups, but rather as an optimistic mechanism to directly improve disadvantaged people’s lives. The article argues that when coupled with long-term housing, a weak form of paternalist welfare for people who have experienced chronic homelessness can be justified.