Polarization Induced Switching Effect in Graphene Nanoribbon Edge-Defect Junction

With nonequilibrium Green's function approach combined with density functional theory, we perform an ab initio calculation to investigate transport properties of graphene nanoribbon junctions self-consistently. Tight-binding approximation is applied to model the zigzag graphene nanoribbon (ZGNR) electrodes, and its validity is confirmed by comparison with GAUSSIAN03 PBC calculation of the same system. The origin of abnormal jump points usually appearing in the transmission spectrum is explained with the detailed tight-binding ZGNR band structure. Transport property of an edge defect ZGNR junction is investigated, and the tunable tunneling current can be sensitively controlled by transverse electric fields.Comment: 18 pages, 8 figure

Interfacial layering in a three-component polymer system

We study theoretically the temporal evolution and the spatial structure of the interface between two polymer melts involving three different species (A, A* and B). The first melt is composed of two different polymer species A and A* which are fairly indifferent to one another (Flory parameter chi_AA* ~ 0). The second melt is made of a pure polymer B which is strongly attracted to species A (chi_AB 0). We then show that, due to these contradictory tendencies, interesting properties arise during the evolution of the interface after the melts are put into contact: as diffusion proceeds, the interface structures into several adjacent "compartments", or layers, of differing chemical compositions, and in addition, the central mixing layer grows in a very asymmetric fashion. Such unusual behaviour might lead to interesting mechanical properties, and demonstrates on a specific case the potential richness of multi-component polymer interfaces (as compared to conventional two-component interfaces) for various applications.Comment: Revised version, to appear in Macromolecule

Density functional calculations of nanoscale conductance

Density functional calculations for the electronic conductance of single molecules are now common. We examine the methodology from a rigorous point of view, discussing where it can be expected to work, and where it should fail. When molecules are weakly coupled to leads, local and gradient-corrected approximations fail, as the Kohn-Sham levels are misaligned. In the weak bias regime, XC corrections to the current are missed by the standard methodology. For finite bias, a new methodology for performing calculations can be rigorously derived using an extension of time-dependent current density functional theory from the Schroedinger equation to a Master equation.Comment: topical review, 28 pages, updated version with some revision

The Impact of Nurse-Led Environmental Controls on Insomnia in Elderly Acute Care Inpatients

The Impact of Nurse-Led Environmental Controls on Insomnia in Elderly Acute Care Inpatients Research Question: Does teaching nurses to control the patient environment (I) in acute care in-patients aged 65+ (P) reduce insomnia compared to current practice (Q1H rounding) (C) from 67.4% to less than 30% as measured by the Insomnia Severity Index (ISI) (O)? Background and Significance: 67.4% of hospitalized patients report experiencing insomnia from sleep disturbances, which can significantly impact their recovery and overall health outcomes. Nurses can address these disruptions by monitoring noise, light exposure, and staff interruptions. Sample methods: The literature review search keywords were sleep hygiene, sleep hygiene therapy, improved sleep, factors affecting sleep, sleep in hospitalized patients, insomnia, delirium, sleep disorders, acute-care sleep therapy, med-surg sleep therapy, geriatric, ages 65+. The search was conducted using the databases CINAHL and PubMed, resulting in 75 research studies. After applying filters for the last 5 years, RN author or application, RCT or quasi-experimental, and English language, the sample yielded 10. Sample: Three studies on insomnia and non-pharmacological interventions for improvement in sleep hygiene. Results: The body of evidence shows that environmental control interventions are statistically significant in reducing insomnia severity in acute care inpatients aged 65+, as measured by the Insomnia Severity Index (ISI). Conclusion: Implementing nurse-led environmental modifications to improve sleep quality in acute inpatients aged 65+ is recommended as a change in practice. Future research should explore the long-term effects of these interventions on patient outcomes related to insomnia and hospitalization-related complications

Developments in the negative-U modelling of the cuprate HTSC systems

The paper deals with the many stands that go into creating the unique and complex nature of the HTSC cuprates above Tc as below. Like its predecessors it treats charge, not spin or lattice, as prime mover, but thus taken in the context of the chemical bonding relevant to these copper oxides. The crucial shell filling, negative-U, double-loading fluctuations possible there require accessing at high valent local environment as prevails within the mixed valent, inhomogeneous two sub-system circumstance of the HTSC materials. Close attention is paid to the recent results from Corson, Demsar, Li, Johnson, Norman, Varma, Gyorffy and colleagues.Comment: 44 pages:200+ references. Submitted to J.Phys.:Condensed Matter, Sept 7 200

When Should Co-Authorship Be Given to AI?

If an AI makes a significant contribution to a research paper, should it be listed as a co-author? The current guidelines in the field have been created to reduce duplication of credit between two different authors in scientific articles. A new computer program could be identified and credited for its impact in an AI research paper that discusses an early artificial intelligence system which is currently under development at Lawrence Berkeley National. One way to imagine the future of artificial intelligence is that it will be much less expensive to develop new technologies than to create new ways of thinking. Now we have done this technology, and now we go and ask why in the end it is the artificial intelligence that takes over? Well, it is not that artificial intelligence is bad, but it is not as effective as human minds or as intelligent as machine minds. Even in the past, when computers were more intelligent than humans, not all the AI programs have been so intelligent as to be intelligent enough to be called intelligent

Explaining the decline in coronary heart disease mortality in Turkey between 1995 and 2008.

BACKGROUND: Coronary heart disease (CHD) mortality rates have been decreasing in Turkey since the early 1990s. Our study aimed to determine how much of the CHD mortality decrease in Turkey between 1995 and 2008 could be attributed to temporal trends in major risk factors and how much to advances in medical and surgical treatments. METHODS: The validated IMPACT CHD mortality model was used to combine and analyse data on uptake and effectiveness of CHD treatments and risk factor trends in Turkey in adults aged 35-84 years between 1995 and 2008.Data sources were identified, searched and appraised on population, mortality and major CHD risk factors for adults those aged 35-84 years. Official statistics, electronic databases, national registers, surveys and published trials were screened from 1995 onwards. RESULTS: Between 1995 and 2008, coronary heart disease mortality rates in Turkey decreased by 34% in men and 28% in women 35 years and over. This resulted in 35,720 fewer deaths in 2008.Approximately 47% of this mortality decrease was attributed to treatments in individuals (including approximately 16% to secondary prevention, 3% angina treatments, 9% to heart failure treatments, 5% to initial treatments of acute myocardial infarction, and 5% to hypertension treatments) and approximately 42% was attributable to population risk factor reductions (notably blood pressure 29%; smoking 27%; and cholesterol 1%). Adverse trends were seen for obesity and diabetes (potentially increasing mortality by approximately 11% and 14% respectively). The model explained almost 90% of the mortality fall. CONCLUSION: Reduction in major cardiovascular risk factors explained approximately 42% and improvements in medical and surgical treatments explained some 47% of the CHD mortality fall. These findings emphasize the complimentary value of primary prevention and evidence-based medical treatments in controlling coronary heart disease

Understanding and Supporting Full-Time Non-Tenure-Track Faculty

As the face of the American faculty profession changes, targeted academic development becomes more important. A phenomenological qualitative study of full-time, non-tenure-track faculty in English portrays an experience characterized by a love of teaching but fraught with professional challenges stemming from low status and poor reward and recognition structures. These data provide the point of departure for recommendations on expanding organizational and faculty development strategies for supporting, integrating, and encouraging full-time, non-tenure-track faculty