472 research outputs found
Relaxation time spectrum of low-energy excitations in one- and two-dimensional materials with charge or spin density waves
The long-time thermal relaxation of (TMTTF)Br, SrCuO
and SrCaCuO single crystals at temperatures below 1 K
and magnetic field up to 10 T is investigated. The data allow us to determine
the relaxation time spectrum of the low energy excitations caused by the
charge-density wave (CDW) or spin-density wave (SDW). The relaxation time is
mainly determined by a thermal activated process for all investigated
materials. The maximum relaxation time increases with increasing magnetic
field. The distribution of barrier heights corresponds to one or two Gaussian
functions. The doping of SrCaCuO with Ca leads to
a drastic shift of the relaxation time spectrum to longer time. The maximum
relaxation time changes from 50 s (x = 0) to 3000 s (x = 12) at 0.1 K and 10 T.
The observed thermal relaxation at x=12 clearly indicates the formation of the
SDW ground state at low temperatures
The loop structure and the RNA helicase p72/DDX17 influence the processing efficiency of the mice miR-132
miRNAs are small RNAs that are key regulators of gene expression in eukaryotic organisms. The processing of miRNAs is regulated by structural characteristics of the RNA and is also tightly controlled by auxiliary protein factors. Among them, RNA binding proteins play crucial roles to facilitate or inhibit miRNA maturation and can be controlled in a cell, tissue and species-specific manners or in response to environmental stimuli. In this study we dissect the molecular mechanism that promotes the overexpression of miR-132 in mice over its related, co-transcribed and co-regulated miRNA, miR-212. We have shown that the loop structure of miR-132 is a key determinant for its efficient processing in cells. We have also identified a range of RNA binding proteins that recognize the loop of miR-132 and influence both miR-132 and miR-212 processing. The DEAD box helicase p72/DDX17 was identified as a factor that facilitates the specific processing of miR-132
Interplay between phase defects and spin polarization in the specific heat of the spin density wave compound (TMTTF)_2Br in a magnetic field
Equilibrium heat relaxation experiments provide evidence that the ground
state of the commensurate spin density wave (SDW) compound (TMTTF)Br after
the application of a sufficient magnetic field is different from the
conventional ground state. The experiments are interpreted on the basis of the
local model of strong pinning as the deconfinement of soliton-antisoliton pairs
triggered by the Zeeman coupling to spin degrees of freedom, resulting in a
magnetic field induced density wave glass for the spin carrying phase
configuration.Comment: 4 pages, 5 figure
The development of absorptive capacity-based innovation in a construction SME
Traditionally, construction has been a transaction-oriented industry. However, it is changing from the design-bid-build process into a business based on innovation capability and performance management, in which contracts are awarded on the basis of factors such as knowledge, intellectual capital and skills. This change presents a challenge to construction-sector SMEs with scarce resources, which must find ways to innovate based on those attributes to ensure their future competitiveness. This paper explores how dynamic capability, using an absorptive capacity framework in response to these challenges, has been developed in a construction-based SME. The paper also contributes to the literature on absorptive capacity and innovation by showing how the construct can be operationalized within an organization. The company studied formed a Knowledge Transfer Partnership using action research over a two-year period with a local university. The aim was to increase its absorptive capacity and hence its ability to meet the changing market challenges. The findings show that absorptive capacity can be operationalized into a change management approach for improving capability-based competitiveness. Moreover, it is important for absorptive capacity constructs and language to be contextualized within a given organizational setting (as in the case of the construction-based SME in the present study)
The relationship between irrigation-induced electrical loads and antecedent weather conditions in Tasmania, Australia
Over the past decade in Australia, there has been a general trend towards the introduction of electrical motors to operate irrigation pumps. While electrical motors provide many advantages over the alternatives, electrical loads can aggregate in some areas to become large peaks, which challenge the existing electrical distribution networks. This is especially true during extreme hot or dry periods, when irrigators collectively demand significant electrical resources at the same time. While there is an inherent link between weather conditions and the amount of electricity used for irrigation, this relationship is poorly understood. Previous studies have either focused on localised data related to concurrent temperature, rainfall and soil moisture, or they have annualised summaries over large areas. In this study, we compare intensive irrigation periods with the drought factor at a case study irrigation scheme in Tasmania, Australia, finding a strong relationship between electrical load and periods when the drought factor is > 6. This relatively simple relationship may be useful for managers of electricity supply and distribution, managers of water resources, and irrigators, as it may be used to minimise the risk of exceeding the capacity of the electricity network, improve water availability and optimise irrigation scheduling
Post-Disaster Housing Reconstruction in Sri Lanka: What Methodology?
Research methodology is the procedural framework within which the research is conducted. This includes the overall
approach to a problem that could be put into practice in a research process, from the theoretical underpinning to the
collection and analysis of data. Choice of methodology depends on the primary drivers: topic to be researched and the
specific research questions. Hence, methodological perspectives of managing stakeholder expectations of PDHR context
are composed of research philosophies, research strategy, research design, and research techniques. This research belonged
to social constructivism or interpretivism within a philosophical continuum. The nature of the study was more toward
subjectivism where human behavior favored voluntary stance. Ontological, methodological, epistemological, and axiological
positioning carried the characteristics of idealism, ideographic, anti-positivism, and value laden, respectively. Data collection
comprises two phases, preliminary and secondary. Exploratory interviews with construction experts in the United Kingdom
and Sri Lanka were carried out to refine the interview questions and identify the case studies. Case study interviews during
the secondary phase took place in Sri Lanka. Data collected at the preliminary stage were used to assess the attributes of
power, legitimacy/proximity, and urgency of stakeholders to the project using Stakeholder Circle™ software. Moreover,
the data collected at secondary phase via case studies will be analyzed with NVivo 8. This article aims to discuss these
methodological underpinnings in detail applied in a post-disaster housing reconstruction context in Sri Lanka
Reducing Systems Implementation Failure: A conceptual Framework for the Improvement of Financial Systems Implementations within the Financial Services Industries
The financial industry continues to change, become more global, complex and important to economies all around the work. The industry continues to be in flux and the world financial crisis has resulted in changes that have changed the industry for good. The need for agile, accurate and detailed financial systems has never been so important. This research discusses the issues associated with implementing financial systems within financial services companies, a conceptual framework has been built that will help reduce the risk of implementation failure in future financial systems implementations. Financial experts can use the framework to reduce system implementation risk; help deliver projects on time to budget whilst meet the functionality requirements of stakeholders
Strong-Pinning Effects in Low-Temperature Creep: Charge-Density Waves in TaS_3
Nonlinear conduction in the quasi-one dimensional conductor o-TaS_3 has been
studied in the low-temperature region down to 30 mK. It was found that at
temperatures below a few Kelvins the current-voltage (I-V) characteristics
consist of several branches. The temperature evolution of the I-V curve
proceeds through sequential freezing-out of the branches. The origin of each
branch is attributed to a particular strong pinning impurity type.
Similar behavior is expected for other physical systems with collective
transport (spin-density waves, Wigner crystals, vortex lattices in type-II
superconductors etc.) in the presence of strong pinning centers.Comment: 11 pages, 3 ps figures, Revtex, To be published in Phys. Rev. Letters
(1997
Myositis complicating benzathine penicillin-G injection in a case of rheumatic heart disease
Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND
license (http://creativecommons.org/licenses/by-nc-nd/4.0/).A 7-year old boy developed myositis secondary to intramuscular injection of benzathine penicillin-G in the context of secondary prophylaxis for rheumatic heart disease. Side effects of intramuscular delivery of benzathine penicillin-G are well described and include injection site pain and inflammation, but myositis, as depicted on magnetic resonance imaging in this case, has not previously been described
Heatwave and health impact research : a global review
Background Observed increases in the frequency and intensity of heatwave events, together with the projected acceleration of these events worldwide, has led to a rapid expansion in research on the health impacts of extreme heat. Objective To examine how research on heatwaves and their health-related impact is distributed globally. Methods A systematic review was undertaken. Four online databases were searched for articles examining links between specific historical heatwave events and their impact on mortality or morbidity. The locations of these events were mapped at a global scale, and compared to other known characteristics that influence heat-related illness and death. Results When examining the location of heatwave and health impact research worldwide, studies were concentrated on mid-latitude, high-income countries of low- to medium-population density. Regions projected to experience the most extreme heatwaves in the future were not represented. Furthermore, the majority of studies examined mortality as a key indicator of population-wide impact, rather than the more sensitive indicator of morbidity. Conclusion While global heatwave and health impact research is prolific in some regions, the global population most at risk of death and illness from extreme heat is under-represented. Heatwave and health impact research is needed in regions where this impact is expected to be most severe
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