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We have studied Bi2Se3 at its 2D-limit using scanning tunneling spectroscopy (STS). Bulk Bi2Se3 is a well-known topological insulator having gapless surface states. In the 2D limit, the interior of the material exhibits a band gap, whereas the periphery shows a gapless metallic state having a Dirac point. We demonstrate a method to tune the Fermi energy and hence the Dirac point of Bi2Se3 nanoplates through doping at the anionic site. For this purpose, STS measurements were carried out on the Bi2Se3 system. We have used bromide as a dopant, which turns the material to n-type in nature. As a result, STS studies infer that the Fermi energy (EF) shifted toward the conduction band and consequently the Dirac point could be found to move away from Fermi energy. Through STS measurements, we have demonstrated a correlation between the shift of Dirac point position and the dopant content. The size, shape, and compositions of Bi2Se3 nanoflakes and concentration of bromine in the doped nanostructures were determined using transmission electron microscopy, associated energy dispersive X-ray spectroscopy analysis, and X-ray diffraction.
Inflammation and immune activation have been implicated in the pathogenesis of severe mental disorders and cardiovascular disease (CVD). Despite high level of comorbidity, many studies of the immune system in severe mental disorders have not systematically taken cardiometabolic risk factors into account.
We investigated if inflammatory markers were increased in schizophrenia (SCZ) and affective (AFF) disorders independently of comorbid CVD risk factors. Cardiometabolic risk factors (blood lipids, body mass index and glucose) and CVD-related inflammatory markers CXCL16, soluble interleukin-2 receptor (sIL-2R), soluble CD14 (sCD14), macrophage inhibitory factor and activated leukocyte cell adhesion molecule (ALCAM) were measured in n = 992 patients (SCZ, AFF), and n = 647 healthy controls. We analyzed the inflammatory markers before and after controlling for comorbid cardiometabolic risk factors, and tested for association with psychotropic medication and symptom levels.
CXCL16 (p = 0.03) and sIL-2R (p = 7.8 × 10−5) were higher, while sCD14 (p = 0.05) were lower in patients compared to controls after controlling for confounders, with significant differences in SCZ for CXCL16 (p = 0.04) and sIL-2R (p = 1.1 × 10−5). After adjustment for cardiometabolic risk factors higher levels of sIL-2R (p = 0.001) and lower sCD14 (p = 0.002) remained, also in SCZ (sIL-2R, p = 3.0 × 10−4 and sCD14, p = 0.01). The adjustment revealed lower ALCAM levels (p = 0.03) in patients. We found no significant associations with psychotropic medication or symptom levels.
The results indicate that inflammation, in particular enhanced T cell activation and impaired monocyte activation, are associated with severe mental disorders independent of comorbid cardiometabolic risk factors. This suggests a role of novel pathophysiological mechanisms in severe mental disorders, particularly SCZ.
Measurements of local plasma parameters in dusty plasma are crucial for understanding
the physics issues related to such systems. The Langmuir probe, a small electrode
immersed in the plasma, provides such measurements. However, designing of a Langmuir
probe system in a dusty plasma environment demands special consideration. First, the
probe has to be miniaturized enough so that its perturbation on the ambient dust
structure is minimal. At the same time, the probe dimensions must be such that a
well-defined theory exists for interpretation of its characteristics. The associated
instrumentation must also support the measurement of current collected by the probe
with high signal to noise ratio. The most important consideration, of course, comes
from the fact that the probes are prone to dust contamination, as the dust particles
tend to stick to the probe surface and alter the current collecting area in
unpredictable ways. This article describes the design and operation of a Langmuir
probe system that resolves these challenging issues in dusty plasma. In doing so,
first, different theories that are used to interpret the probe characteristics in
collisionless as well as in collisional regimes are discussed, with special emphasis
on application. The critical issues associated with the current–voltage
characteristics of Langmuir probe obtained in different operating regimes are
discussed. Then, an algorithm for processing these characteristics efficiently in
presence of ion-neutral collisions in the probe sheath is presented.
A plausible mechanism underlying flavonoid-associated cognitive effects is increased cerebral blood flow (CBF). However, behavioural and CBF effects following flavanone-rich juice consumption have not been explored. The aim of this study was to investigate whether consumption of flavanone-rich juice is associated with acute cognitive benefits and increased regional CBF in healthy, young adults. An acute, single-blind, randomised, cross-over design was applied with two 500-ml drink conditions – high-flavanone (HF; 70·5 mg) drink and an energy-, and vitamin C- matched, zero-flavanone control. A total of twenty-four healthy young adults aged 18–30 years underwent cognitive testing at baseline and 2-h after drink consumption. A further sixteen, healthy, young adults were recruited for functional MRI assessment, whereby CBF was measured with arterial spin labelling during conscious resting state at baseline as well as 2 and 5 h after drink consumption. The HF drink was associated with significantly increased regional perfusion in the inferior and middle right frontal gyrus at 2 h relative to baseline and the control drink. In addition, the HF drink was associated with significantly improved performance on the Digit Symbol Substitution Test at 2 h relative to baseline and the control drink, but no effects were observed on any other behavioural cognitive tests. These results demonstrate that consumption of flavanone-rich citrus juice in quantities commonly consumed can acutely enhance blood flow to the brain in healthy, young adults. However, further studies are required to establish a direct causal link between increased CBF and enhanced behavioural outcomes following citrus juice ingestion.
In a quasineutral plasma, electrons undergo collective oscillations, known as plasma oscillations, when perturbed locally. The oscillations propagate due to finite temperature effects. However, the wave can lose the phase coherence between constituting oscillators in an inhomogeneous plasma (phase mixing) because of the dependence of plasma oscillation frequency on plasma density. The longitudinal electric field associated with the wave may be used to accelerate electrons to high energies by exciting large amplitude wave. However when the maximum amplitude of the wave is reached that plasma can sustain, the wave breaks. The phenomena of wave breaking and phase mixing have applications in plasma heating and particle acceleration. For detailed experimental investigation of these phenomena a new device, inverse mirror plasma experimental device (IMPED), has been designed and fabricated. The detailed considerations taken before designing the device, so that different aspects of these phenomena can be studied in a controlled manner, are described. Specifications of different components of the IMPED machine and their flexibility aspects in upgrading, if necessary, are discussed. Initial results meeting the prerequisite condition of the plasma for such study, such as a quiescent, collisionless and uniform plasma, are presented. The machine produces δnnoise/n ⩽ 1%, Luniform ~ 120 cm at argon filling pressure of ~10−4 mbar and axial magnetic field of B = 1090 G.
For SDSS quasar data (2005) we have truncated data structure whereas for the survey of 2007 the data is no longer truncated. This calls for development or use of completely different statistical methodology to study the data for the evolution of the same objects like quasars. These different methodologies suggest different interpretation for a particular phenomenon in nature. This leads to the issue of validation of the data. More intriguing and challenging issue crops up as, given all of the data, what can be said about the laws of physics that have been operating over the universe? Over here we have used the concept of Neural Network to model the relationship between redshift and apparent magnitude.
Botanical microfossils, macroremains and oribatid mites of a Weichselian interstadial deposit in the central Netherlands point to a temporary, sub-arctic wetland in a treeless landscape. Radiocarbon dates and OSL dates show an age between ca. 54.6 and 46.6 ka cal BP. The vegetation succession, starting as a peat-forming wetland that developed into a lake, might well be linked with a Dansgaard-Oeschger climatic cycle. We suggest that during the rapid warming at the start of a D-O cycle, relatively low areas in the landscape became wetlands where peat was formed. During the more gradual temperature decline that followed, evaporation diminished; the wetlands became inundated and lake sediments were formed. During subsequent sub-arctic conditions the interstadial deposits were covered with wind-blown sand. Apart from changes in effective precipitation also the climate-related presence and absence of permafrost conditions may have played a role in the formation of the observed sedimentological sequence from sand to peat, through lacustrine sediment, with coversand on top. The Wageningen sequence may correspond with D-O event 12, 13 or 14. Some hitherto not recorded microfossils were described and illustrated.
The solid oxide membrane (SOM) electrolysis process has been successfully tested on a laboratory scale to produce silicon directly from silica in a cost-effective and eco-friendly way. A one-end-closed yttria-stabilized zirconia (YSZ) tube was employed to separate a molten salt containing dissolved silica from a liquid metal anode placed inside the YSZ tube. When an applied electric potential between a liquid tin cathode in the molten salt and the anode exceeds the dissociation potential of silica, oxygen ions are transported out of the molten salt through the YSZ membrane and oxidized at the anode while the silicon cations in the flux are reduced to silicon on the surface of the liquid tin cathode. A potentiodynamic scan (PDS) was performed to determine the dissociation potential of silica in the molten salt system. Electrolysis was performed at 1.05 V for 8 hours. The presence of high-purity silicon crystals on the surface of liquid tin cathode was confirmed by scanning electron microscopy (SEM) and electron dispersive X-ray spectroscopy (EDS).
Uninterrupted provision of vital energy services (see Chapter 1, Section 1.2.2) – energy security – is a high priority of every nation. Energy security concerns are a key driving force of energy policy. These concerns relate to the robustness (sufficiency of resources, reliability of infrastructure, and stable and affordable prices); sovereignty (protection from potential threats from external agents); and resilience (the ability to withstand diverse disruptions) of energy systems. Our analysis of energy security issues in over 130 countries shows that the absolute majority of them are vulnerable from at least one of these three perspectives. For most industrial countries, energy insecurity means import dependency and aging infrastructure, while many emerging economies have additional vulnerabilities such as insufficient capacity, high energy intensity, and rapid demand growth. In many low-income countries, multiple vulnerabilities overlap, making them especially insecure.
Oil and its products lack easily available substitutes in the transport sector, where they provide at least 90% of energy in almost all countries. Furthermore, the global demand for transport fuels is steadily rising, especially rapidly in Asian emerging economies. Disruptions of oil supplies may thus result in catastrophic effects on such vital functions of modern states as food production, medical care, and internal security. At the same time, the global production capacity of conventional oil is widely perceived as limited. These factors result in rising and volatile prices of oil affecting all economies, especially low-income countries, almost all of which import over 80% of their oil supplies.
The global mobile communication industry is growing rapidly. Today there are already more than 4 billion mobile phone subscribers worldwide , more than half the entire population of the planet. Obviously, this growth is accompanied by an increased energyconsumption of mobile networks. Global warming and heightened concerns for the environment of the planet require a special focus on the energy efficiency of these systems .
Many approaches to wireless energy-efficiency are limited to the power consumption of single nodes, e.g. a base station –. This scope is comparably easy to specify and to measure, but it fails to capture the network performance aspects (e.g. system throughput) implied by coverage and interference issues. Other methodologies are very broad, capturing the ICT industry in total . Recently an assessment framework for the power consumption of deployed wireless networks has been published, the mobile energyefficiency (MEE) network benchmarking service , based on metering all components of a network. However, for the energy efficiency it is not possible to directly compare, e.g. an Indian network with a Scandinavian network, therefore MEE has to introduce correction terms for the climate, for the number of base stations operated off-grid, and for the generations of equipment in the field.
However, the above approaches do not give insight into which parts of a network are most energy intensive or which provide the highest energy-saving potentials. There is a need for a simulation tool studying theoretically the effect of improvements in hardware, deployment strategies, and network management.
A 7-year-old child was noted to have dextrojuxtaposition of the left atrial appendage at the time of surgical atrial septal defect repair. Given the favourable anatomic location and size of the atrial appendage, it was inverted and used to close the atrial defect. This is the first report of atrial septal defect repair using a juxtaposed atrial appendage. The cardiac anatomy and theoretical benefits of this repair are discussed.
One of Hungary's geological and environmental treasures is nestled in the heart of the Great Hungarian Plain. The catchment basin of Lake Kolon was subjected to detailed environmental historical studies starting in 2005. Undisturbed cores taken along transects of the basin were subjected to detailed sedimentological, paleoecological, and geochemical studies. To establish a reliable timeframe of the lacustrine and marshland sedimentary sequence identified, 22 samples were analyzed by accelerator mass spectrometry (AMS) in the radiocarbon laboratories of Poznań and Tucson. With the new results in hand, we had the opportunity to elucidate the geological evolution of the area for the past 25,000 yr. This sequence is highly beneficial, as it is probably the most well-dated profile of the Quaternary from the area studied. The new absolute dates enabled the comparison of local geological evolution of the studied area with those of global climatic changes. As seen from our findings, the geological evolution of the catchment basin was congruent with major climatic events during the Pleistocene and the entire Holocene. However, a very peculiar trajectory was identified for the terminal part of the Pleistocene and the opening of the Holocene regarding the evolution of the landscape, the vegetation, and the fauna of this part of the Great Hungarian Plain.
During the third millennium BC, a rapid and intentional destruction of forests took place over wide regions of Europe to allow a new agricultural economy, often dominated by animal husbandry. By the second millennium BC, these open landscapes were evidently managed to maintain productivity. Much investment was made in infrastructure, from farm buildings and field systems to trackways. In opposition to a landscape enclosed by forests, these new open landscapes provided new avenues of visibility and interconnectivity, and with innovative uses of chariots, wagons, and ships, easier and faster communications opened up. Monumental barrows and large settlements had a dramatic visual impact that could easily have defined property rights and a more visible settlement hierarchy as people moved across the landscape.
However, a more permanently open landscape also introduced concerns of maintaining productivity. Soil, especially the light soils, became more prone to erosive forces as well as nutrient depletion, especially when no longer sustained by forest regeneration. Instead, fertility had to be maintained by other cultural practices, including fallow, application of manure, and forest management. Despite such care, ecological crises sometimes would strike, as happened in the heavily settled and exposed landscape of Thy on the North Sea coast of Jutland. The dominant herding economy and the demands for timber for large farm buildings led to a near-extinction of proper forests, peat was used for heating, and driftwood was sometimes used in house construction. In contrast in both central Hungary and western Sicily, agricultural intensification led to soil erosion, certainly from later Bronze Age times and increasing in intensity and scale over time. Thus the extensive agricultural environments of the Bronze Age introduced the potential for overexploitation of the land and different human responses to this, as exemplified in our case studies.
To our knowledge, no comprehensive, interdisciplinary initiatives have been taken to examine the role of genetic variants on patient-reported quality-of-life outcomes. The overall objective of this paper is to describe the establishment of an international and interdisciplinary consortium, the GENEQOL Consortium, which intends to investigate the genetic disposition of patient-reported quality-of-life outcomes. We have identified five primary patient-reported quality-of-life outcomes as initial targets: negative psychological affect, positive psychological affect, self-rated physical health, pain, and fatigue. The first tangible objective of the GENEQOL Consortium is to develop a list of potential biological pathways, genes and genetic variants involved in these quality-of-life outcomes, by reviewing current genetic knowledge. The second objective is to design a research agenda to investigate and validate those genes and genetic variants of patient-reported quality-of-life outcomes, by creating large datasets. During its first meeting, the Consortium has discussed draft summary documents addressing these questions for each patient-reported quality-of-life outcome. A summary of the primary pathways and robust findings of the genetic variants involved is presented here. The research agenda outlines possible research objectives and approaches to examine these and new quality-of-life domains. Intriguing questions arising from this endeavor are discussed. Insight into the genetic versus environmental components of patient-reported quality-of-life outcomes will ultimately allow us to explore new pathways for improving patient care. If we can identify patients who are susceptible to poor quality of life, we will be able to better target specific clinical interventions to enhance their quality of life and treatment outcomes.
A comparative study of the susceptibility of monkey kidney, Hep 2 and HeLa cells to enteroviruses and adenoviruses is made. It seems that this Hep 2 cell line is as effective as the monkey kidney cells in their susceptibility to vaccine strains of polioviruses and far better than monkey kidney cells in their susceptibility to strains of ECHO 6 and ECHO 11 from clinical material. It is as effective as, or slightly better than, HeLa cells for the isolation of adenoviruses. It also compares favourably with monkey kidney cells for the isolation of other enteroviruses.
We are most grateful to Glaxo Laboratories Ltd. for the supplies of monkey kidney cells used in this investigation.