Effect of Adiabatic Phonons on Striped and Homogeneous Ground States

The effects of adiabatic phonons on a spin-fermion model for high T_c cuprates are studied using numerical simulations. In the absence of electron-phonon interactions (EPI), stripes in the ground state are observed for certain dopings while homogeneous states are stabilized in other regions of parameter space. Different modes of adiabatic phonons are added to the Hamiltonian:breathing, shear and half-breathing modes. Diagonal and off-diagonal electron-phonon couplings are considered. It is observed that strong diagonal EPI generate stripes in previously homogeneous states, while in striped ground states an increase in the diagonal couplings tends to stabilize the stripes, inducing a gap in the density of states (DOS) and rendering the ground state insulating. The off-diagonal terms, on the other hand, destabilize the stripes creating inhomogeneous ground states with a pseudogap at the chemical potential in the DOS. The breathing mode stabilizes static diagonal stripes; while the half-breathing (shear) modes stabilize dynamical (localized) vertical and horizontal stripes. The EPI induces decoherence of the quasi-particle peaks in the spectral functions.Comment: latex, 9 pages,13 figure

Volumetric evaluation of hemicerebellar changes in migraine patients without aura

Brain balance changes have been recognised in migraine, but cerebellar function between or during attacks has been assessed only in a few studies. Previous studies have indicated that migraine affects cerebellar function. In the present study we aimed to evaluate the hemicerebellar volume changes of patients with migraine without aura (MWoA). Volumetric changes of cerebellar hemispheres were evaluated in terms of asymmetry using stereological methods on magnetic resonance images (MRI) retrospectively. Nineteen patients with MWoA and 18 age- and gender-matched control subjects were included in the study. MRIs were analysed by using the point-counting approach of stereological methods by Cavalier’s principle. There was no statistically significant cerebellar atrophy or hemicerebellar asymmetry between the MWoA and control subjects. There was no cerebellar atrophy or asymmetry between the MWoA and age-matched control group. The stereological evaluation of cerebellar asymmetry and atrophy in humans is important for both clinicians and anatomists. The technique is simple, inexpensive, and reliable. (Folia Morphol 2011; 70, 4: 235–239

Distributed and biometric signature-based identity proofing system for the maritime sector

The maritime sector is an industry that faces significant and various challenges related to cyber security and data management, such as fraud and user authentication. Therefore, there is a need for a secure solution that can effectively manage data transactions while resolving digital identity. A biometric signature application in blockchain for fighting fraud and fake identities may provide a solution in the maritime sector. This research proposes a biometric signature and an IPFS network-blockchain framework to address these challenges. This paper also discusses the proposed framework's cyber security challenges that threaten behavioral biometric security

Probabilistic Performance Assessment of a Low-Level Radioactive Waste Disposal Site on the Nevada Test Site

The Area 5 Radioactive Waste Management Site on the Nevada Test Site has been disposing of low-level, mixed low-level, and transuranic radioactive waste since 1961. In 1988, the U.S. Department of Energy implemented performance objectives for low-level radioactive waste disposal site performance and required all site operators to prepare a performance assessment. Since then, an iterative performance assessment process has been implemented that consists of repeated cycles of site characterization, conceptual model formation/revision, and performance assessment modeling. At the end of each cycle uncertainty and sensitivity analysis are used to determine the need for revision and to identify topics requiring additional research and development. The performance assessment model is implemented in the GoldSim{reg_sign} probabilistic simulation platform. The current site conceptual model, based on site characterization data and process model results, assumes that there is no groundwater pathway under current climatic conditions and that radionuclide releases are predominately upward to the land surface. Radionuclides are released to the land surface by upward liquid advection/diffusion, gas diffusion, biointrusion, and inadvertent human intrusion. The model calculates dose for four members of public exposure scenarios and two intruder scenarios. The highest mean-dose, 0.04 mSv yr{sup -1}, is expected for a low-probability exposure scenario: establishment of a rural community at the site boundary at the end of institutional control. At the end of institutional control, doses are contributed primarily by {sup 3}H in agricultural products produced onsite. After approximately 300 years, the doses are contributed equally by {sup 99}Tc and {sup 210}Pb ingested in vegetables grown at the residence. Technetium is released to the surface by the coupled processes of liquid advection/diffusion occurring deep in the cover and plant uptake/animal burrowing occurring at shallower depths. Lead-210 is deposited in shallow cover soil by the radioactive decay of {sup 222}Rn diffusing in the gas phase. The highest mean dose for the more likely exposure scenario of transient recreational use of the site is 0.002 mSv yr{sup -1}. The transient visitor's dose is contributed predominantly by external irradiation from {sup 214}Pb and {sup 214}Bi, deposited in the cover by diffusion of {sup 222}Rn

The effect of epidural anesthesia on muscle flap tolerance to venous ischemia

Background: Venous ischemia is a major cause of failure after free tissue transfers and replantations. The combination of general and epidural anesthesia leads to vasodilatation and improves tissue perfusion. Postoperative pain relief and sympathetic blockage are additional benefits of epidural anesthesia. The purpose of this study was to determine whether epidural anesthesia has benefits on microcirculation and neutrophil functions in muscle flaps subjected to venous ischemia. METHOD:: Thirty Sprague-Dawley rats were divided into three groups: group I, general anesthesia; group II, spinal anesthesia; and group III, epidural anesthesia. Cremaster flaps were prepared, postcapillary venules were selected under intravital videomicroscopy, and flaps were subjected to venous ischemia. Images were recorded from preselected postcapillary venules before venous ischemia (baseline) and following reperfusion. Neutrophil rolling and adhesion, functional capillary density, and diameters of postcapillary venules were evaluated. Results: The increase in rolling neutrophils in group III was significantly lower than in groups I and II at 60 and 120 minutes. Change of adherent neutrophils in group III was significantly lower than in groups I and II at 15, 60 and 120 minutes. There was significantly more reduction in inner diameter of postcapillary venules in groups I and II compared with group III. Functional capillary density in groups I and II was significantly lower than in group III. Conclusion: Epidural anesthesia regulated neutrophil functions, salvaged functional capillaries, and prevented vasoconstriction of postcapillary venules in cremaster muscle flaps subjected to venous ischemia. Spinal and general anesthesia, however, were found to be ineffective in improving microcirculation of muscle flaps subjected to venous ischemia. © 2009 by the American Society of Plastic Surgeons

Treponema denticola chymotrypsin-like proteinase may contribute to orodigestive carcinogenesis through immunomodulation

Background: Periodontal pathogens have been linked to oral and gastrointestinal (orodigestive) carcinogenesis. However, the exact mechanisms remain unknown. Treponema denticola (Td) is associated with severe periodontitis, a chronic inflammatory disease leading to tooth loss. The anaerobic spirochete Td is an invasive bacteria due to its major virulence factor chymotrypsin-like proteinase. Here we aimed to investigate the presence of Td chymotrypsin-like proteinase (Td-CTLP) in major orodigestive tumours and to elucidate potential mechanisms for Td to contribute to carcinogenesis. Methods: The presence of Td-CTLP within orodigestive tumour tissues was examined using immunohistochemistry. Oral, tonsillar, and oesophageal squamous cell carcinomas, alongside gastric, pancreatic, and colon adenocarcinomas were stained with a Td-CTLP-specific antibody. Gingival tissue from periodontitis patients served as positive controls. SDS-PAGE and immunoblot were used to analyse the immumodulatory activity of Td-CTLP in vitro. Results: Td-CTLP was present in majority of orodigestive tumour samples. Td-CTLP was found to convert pro MMP-8 and -9 into their active forms. In addition, Td-CTLP was able to degrade the proteinase inhibitors TIMP-1, TIMP-2, and alpha-1-antichymotrypsin, as well as complement C1q. Conclusions: Because of its presence within tumours and regulatory activity on proteins critical for the regulation of tumour microenvironment and inflammation, the Td-CTLP may contribute to orodigestive carcinogenesis.Peer reviewe

Genetic influences on cost-efficient organization of human cortical functional networks

The human cerebral cortex is a complex network of functionally specialized regions interconnected by axonal fibers, but the organizational principles underlying cortical connectivity remain unknown. Here, we report evidence that one such principle for functional cortical networks involves finding a balance between maximizing communication efficiency and minimizing connection cost, referred to as optimization of network cost-efficiency. We measured spontaneous fluctuations of the blood oxygenation level-dependent signal using functional magnetic resonance imaging in healthy monozygotic (16 pairs) and dizygotic (13 pairs) twins and characterized cost-efficient properties of brain network functional connectivity between 1041 distinct cortical regions. At the global network level, 60% of the interindividual variance in cost-efficiency of cortical functional networks was attributable to additive genetic effects. Regionally, significant genetic effects were observed throughout the cortex in a largely bilateral pattern, including bilateral posterior cingulate and medial prefrontal cortices, dorsolateral prefrontal and superior parietal cortices, and lateral temporal and inferomedial occipital regions. Genetic effects were stronger for cost-efficiency than for other metrics considered, and were more clearly significant in functional networks operating in the 0.09–0.18 Hz frequency interval than at higher or lower frequencies. These findings are consistent with the hypothesis that brain networks evolved to satisfy competitive selection criteria of maximizing efficiency and minimizing cost, and that optimization of network cost-efficiency represents an important principle for the brain's functional organization

Performance of Evapotranspirative Covers Under Enhanced Precipitation: Preliminary Data

Since January 2001, drainage lysimeter studies have been conducted at Yucca Flat, on the Nevada Test Site, in support of an evapotranspirative cover design. Yucca Flat has an arid climate with average precipitation of 16.5 cm annually. The facility consists of six drainage lysimeters 3 m in diameter, 2.4 m deep, and backfilled with a single layer of native soil. The bottom of each lysimeter is sealed and equipped with a small drain that enables direct measurement of saturated drainage. Each lysimeter has eight time-domain reflectometer probes to measure moisture content-depth profiles paired with eight heat-dissipation probes to measure soil-water potential depth profiles. Sensors are connected to dataloggers which are remotely accessed via a phone line. The six lysimeters have three different surface treatments: two are bare-soil; two were revegetated with native species (primarily shadscale, winterfat, ephedra, and Indian rice grass); and two were allowed to revegetate naturally with such species as Russian thistle, halogeton, tumblemustard and cheatgrass. Beginning in October 2003, one half of the paired cover treatments (one bare soil, one invader species, and one native species) were irrigated with an amount of water equal to two times the natural precipitation to achieve a three times natural precipitation treatment. From October 2003 through December 2005, all lysimeters received 52.8 cm precipitation, and the four irrigated lysimeters received an extra 105.6 cm of irrigation. No drainage has occurred from any of the nonirrigated lysimeters, but moisture has accumulated at the bottom of the bare-soil lysimeter and the native-plant lysimeter. All irrigated lysimeters had some drainage. The irrigated baresoil lysimeter had 48.3 cm of drainage or 26.4 percent of the combined precipitation and applied irrigation for the entire monitoring record. The irrigated invader species lysimeter had 5.8 cm of drainage, about 3.2 percent of the combined precipitation and applied irrigation. An irrigation valve failure caused an additional 50.8 cm of irrigation to be applied to the irrigated native plant lysimeter. There has been 29.3 cm of drainage from this lysimeter, which is 11.5 percent of the total applied water. Approximately 40 percent of the drainage from the irrigated native plant lysimeter occurred within four weeks of the valve failure