Quintessential inflation from 5D warped product spaces on a dynamical foliation

Assuming the existence of a 5D purely kinetic scalar field on the class of warped product spaces we investigate the possibility of mimic both an inflationary and a quintessential scenarios on 4D hypersurfaces, by implementing a dynamical foliation on the fifth coordinate instead of a constant one. We obtain that an induced chaotic inflationary scenario with a geometrically induced scalar potential and an induced quasi-vacuum equation of state on 4D dynamical hypersurfaces is possible. While on a constant foliation the universe can be considered as matter dominated today, in a family of 4D dynamical hypersurfaces the universe can be passing for a period of accelerated expansion with a deceleration parameter nearly -1. This effect of the dynamical foliation results negligible at the inflationary epoch allowing for a chaotic scenario and becomes considerable at the present epoch allowing a quintessential scenario.Comment: 7 pages, 1 figure Accepted for publication in Modern Physics Letters

Thermoreflectance Measurement of Temperature and Thermal Resistance of Thin Film Gold

To improve performance and reliability of integrated circuits, accurate knowledge of thermal transport properties must be possessed. In particular, reduced dimensions increase boundary scattering and the significance of thermal contact resistance. A thermoreflectance measurement can be used with a valid heat transport model to experimentally quantify the contact thermal resistance of thin film interconnects. In the current work, a quasi-steady state thermoreflectance measurement is used to determine the temperature distribution of a thin film gold interconnect (100 nm) undergoing Joule heating. By comparing the data to a heat transport model accounting for thermal diffusion, dissipation, and Joule heating, a measure of the thermal dissipation or overall thermal resistance of unit area is obtained. The gold film to substrate overall thermal resistance of unit area beneath the wide lead (10 lm) and narrow line (1 lm) of the interconnect are 1.64 Â 10 À6 m 2 K=W and 5.94 Â 10 À6 m 2 K=W, respectively. The thermal resistance of unit area measurements is comparable with published results based on a pump-probe thermoreflectance measurement

Ceramics studio to podiatry clinic: The impact of multi-media resources in the teaching of practical skills across diverse disciplines

This paper draws on the experiences of students from two vastly different disciplines to both explore the theoretical background supporting the use of multimedia resources to teach practical skills and provide a qualitative evaluation of student perceptions and experiences of using bespoke resources. Within ceramics and podiatry, practical skills are traditionally taught via an apprenticeship model within small groups. We explore the practical and pedagogic benefits of developing bespoke multimedia resources to teach practical skills, identifying common themes from these disparate discipline areas. Student focus groups revealed that, practically, the opportunity for repeated viewing at convenient times promoted less reliance on lecturers and better preparation prior to practical demonstrations. Pedagogically, time for reflection and sense making underpinned an increase in confidence which in turn led to increased creativity. The student voice was also used to identify recommendations and challenges driving future change

Conformally flat spacetimes and Weyl frames

We discuss the concepts of Weyl and Riemann frames in the context of metric theories of gravity and state the fact that they are completely equivalent as far as geodesic motion is concerned. We apply this result to conformally flat spacetimes and show that a new picture arises when a Riemannian spacetime is taken by means of geometrical gauge transformations into a Minkowskian flat spacetime. We find out that in the Weyl frame gravity is described by a scalar field. We give some examples of how conformally flat spacetime configurations look when viewed from the standpoint of a Weyl frame. We show that in the non-relativistic and weak field regime the Weyl scalar field may be identified with the Newtonian gravitational potential. We suggest an equation for the scalar field by varying the Einstein-Hilbert action restricted to the class of conformally-flat spacetimes. We revisit Einstein and Fokker's interpretation of Nordstr\"om scalar gravity theory and draw an analogy between this approach and the Weyl gauge formalism. We briefly take a look at two-dimensional gravity as viewed in the Weyl frame and address the question of quantizing a conformally flat spacetime by going to the Weyl frame.Comment: LATEX - 18 page

Frequency-Independent RC Circuit Model for One-Dimensional Carbon Nanostructures

Abstract-We demonstrate that a frequency-independent parallel RC circuit is the simplest model that accurately describes high-frequency electrical conduction in 1-D nanostructures. The resistance is determined from dc measurement, and the capacitance is extracted directly from the measured S-parameters for a ground-signal-ground test structure, without using any fitting parameter. The methodology is applied to carbon nanofibers, and the RC model yields results that are within ±0.5 dB and ±5 • of the measured S-parameters up to 50 GHz. The model is further justified by examining the relationship between S-and Y -parameters of the test network

Foodways in transition: food plants, diet and local perceptions of change in a Costa Rican Ngäbe community

Background Indigenous populations are undergoing rapid ethnobiological, nutritional and socioeconomic transitions while being increasingly integrated into modernizing societies. To better understand the dynamics of these transitions, this article aims to characterize the cultural domain of food plants and analyze its relation with current day diets, and the local perceptions of changes given amongst the Ngäbe people of Southern Conte-Burica, Costa Rica, as production of food plants by its residents is hypothesized to be drastically in recession with an decreased local production in the area and new conservation and development paradigms being implemented. Methods Extensive freelisting, interviews and workshops were used to collect the data from 72 participants on their knowledge of food plants, their current dietary practices and their perceptions of change in local foodways, while cultural domain analysis, descriptive statistical analyses and development of fundamental explanatory themes were employed to analyze the data. Results Results show a food plants domain composed of 140 species, of which 85 % grow in the area, with a medium level of cultural consensus, and some age-based variation. Although many plants still grow in the area, in many key species a decrease on local production–even abandonment–was found, with much reduced cultivation areas. Yet, the domain appears to be largely theoretical, with little evidence of use; and the diet today is predominantly dependent on foods bought from the store (more than 50 % of basic ingredients), many of which were not salient or not even recognized as ‘food plants’ in freelists exercises. While changes in the importance of food plants were largely deemed a result of changes in cultural preferences for store bought processed food stuffs and changing values associated with farming and being food self-sufficient, Ngäbe were also aware of how changing household livelihood activities, and the subsequent loss of knowledge and use of food plants, were in fact being driven by changes in social and political policies, despite increases in forest cover and biodiversity. Conclusions Ngäbe foodways are changing in different and somewhat disconnected ways: knowledge of food plants is varied, reflecting most relevant changes in dietary practices such as lower cultivation areas and greater dependence on food from stores by all families. We attribute dietary shifts to socioeconomic and political changes in recent decades, in particular to a reduction of local production of food, new economic structures and agents related to the State and globalization

Identification of global inhibitors of cellular glycosylation

Small molecule inhibitors of glycosylation enzymes are valuable tools for dissecting glycan functions and potential drug candidates. Screening for inhibitors of glycosyltransferases are mainly performed by in vitro enzyme assays with difficulties moving candidates to cells and animals. Here, we circumvent this by employing a cell-based screening assay using glycoengineered cells expressing tailored reporter glycoproteins. We focused on GalNAc-type O-glycosylation and selected the GalNAc-T11 isoenzyme that selectively glycosylates endocytic low-density lipoprotein receptor (LDLR)-related proteins as targets. Our screen of a limited small molecule compound library did not identify selective inhibitors of GalNAc-T11, however, we identify two compounds that broadly inhibited Golgi-localized glycosylation processes. These compounds mediate the reversible fragmentation of the Golgi system without affecting secretion. We demonstrate how these inhibitors can be used to manipulate glycosylation in cells to induce expression of truncated O-glycans and augment binding of cancer-specific Tn-glycoprotein antibodies and to inhibit expression of heparan sulfate and binding and infection of SARS-CoV-2

User Evaluation of Neonatology Ward Design: An Application of Focus Group and Semantic Differential

[EN] Objective: The object of this article is to identify the set of affective and emotional factors behind users assessments of a space in a neonatology unit and to propose design guidelines based on these. Background: The importance of the neonatology service and the variety of users place great demands on the space at all levels. Despite the repercussions, the emotional aspects of the environment have received less attention. Methods: To avoid incurring limitations in the user mental scheme, this study uses two complementary methodologies: focus group and semantic differential. The (qualitative) focus group methodology provides exploratory information and concepts. The (quantitative) semantic differential methodology then uses these concepts to extract the conceptual structures that users employ in their assessment of the space. Of the total 175 subjects, 31 took part in focus groups and 144 in semantic differential. Results: Five independent concepts were identified: privacy, functionality and professional nature, spaciousness, lighting, and cleanliness. In relation to the importance of the overall positive assessment of the space, the perception of privacy and sensations of dominance and pleasure are fundamental. Six relevant design aspects were also identified: provide spacious surroundings, facilitate sufficient separation between the different posts or cots, use different colors from those usually found in health-care centers, as some aversion was found to white and especially green, design areas with childhood themes, use warm artificial light, and choose user-friendly equipment. Conclusions: Results provide design recommendations of interest and show the possibilities offered by combining both systems to analyze user response.The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work was supported by the Ministerio de Economia y Competitividad, Spain (Project TIN2013-45736-R).Higuera-Trujillo, JL.; Montañana I Aviñó, A.; Llinares Millán, MDC. (2017). User Evaluation of Neonatology Ward Design: An Application of Focus Group and Semantic Differential. HERD Health Environments Research & Design Journal. 10(2):23-48. https://doi.org/10.1177/1937586716641275S234810