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Sample records for rapidly changing magnetic

  1. Rapid change of field line connectivity and reconnection in stochastic magnetic fields

    International Nuclear Information System (INIS)

    Huang, Yi-Min; Bhattacharjee, A.; Boozer, Allen H.

    2014-01-01

    Magnetic fields without a direction of continuous symmetry have the generic feature that neighboring field lines exponentiate away from each other and become stochastic, and hence the ideal constraint of preserving magnetic field line connectivity becomes exponentially sensitive to small deviations from ideal Ohm's law. The idea of breaking field line connectivity by stochasticity as a mechanism for fast reconnection is tested with numerical simulations based on reduced magnetohydrodynamics equations with a strong guide field line-tied to two perfectly conducting end plates. Starting from an ideally stable force-free equilibrium, the system is allowed to undergo resistive relaxation. Two distinct phases are found in the process of resistive relaxation. During the quasi-static phase, rapid change of field line connectivity and strong induced flow are found in regions of high field line exponentiation. However, although the field line connectivity of individual field lines can change rapidly, the overall pattern of field line mapping appears to deform gradually. From this perspective, field line exponentiation appears to cause enhanced diffusion rather than reconnection. In some cases, resistive quasi-static evolution can cause the ideally stable initial equilibrium to cross a stability threshold, leading to formation of intense current filaments and rapid change of field line mapping into a qualitatively different pattern. It is in this onset phase that the change of field line connectivity is more appropriately designated as magnetic reconnection. Our results show that rapid change of field line connectivity appears to be a necessary, but not a sufficient condition for fast reconnection.

  2. Magnetic anisotropy in rapidly quenched amorphous glass-coated nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Óvári, T.-A.; Rotărescu, C.; Atițoaie, A.; Corodeanu, S.; Lupu, N., E-mail: nicole@phys-iasi.ro; Chiriac, H.

    2016-07-15

    Results on the roles played by the magnetoelastic and magnetostatic anisotropy terms in the magnetic behavior of glass-coated magnetostrictive amorphous nanowires prepared by means of rapid solidification are reported. Their contributions have been analyzed both experimentally, through hysteresis loop measurements, and theoretically, using micromagnetic simulations. All the investigated samples exhibit a magnetically bistable behavior, characterized by a single-step magnetization reversal when the applied field reaches a critical threshold value, called switching field. The combined interpretation of the experimental and theoretical data allows one to understand the effect of the magnetoelastic term on the value of the switching field, on one hand, and the effect of the magnetostatic term on the nucleation mechanism on the other, both with an essential impact on the characteristics of the nanowires’ magnetic bistability. The results are crucial for understanding the basic magnetic properties of these novel rapidly solidified ultrathin magnetic wires, as well as for tailoring their properties according to the specific requirements of various sensing applications. - Highlights: • Glass-coated nanowires have been very recently prepared by rapid solidification. • Amorphous wires change their properties as their diameter reaches the nano range. • Here we report on their main anisotropy terms: magnetoelastic and shape. • The results are essential for tailoring their properties for future applications.

  3. Rapidly changing flows in the Earth's core

    DEFF Research Database (Denmark)

    Olsen, Nils; Mandea, M.

    2008-01-01

    A large part of the Earth's magnetic field is generated by fluid motion in the molten outer core(1). As a result of continuous satellite measurements since 1999, the core magnetic field and its recent variations can now be described with a high resolution in space and time(2). These data have...... field occurring over only a few months, indicative of fluid flow at the top of the core, can in fact be resolved. Using nine years of magnetic field data obtained by satellites as well as Earth-based observatories, we determine the temporal changes in the core magnetic field and flow in the core. We...

  4. Rapid magnetic hardening by rapid thermal annealing in NdFeB-based nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Chu, K.-T.; Jin, Z Q; Chakka, Vamsi M; Liu, J P [Department of Physics, University of Texas at Arlington, Arlington, TX 76019 (United States)

    2005-11-21

    A systematic study of heat treatments and magnetic hardening of NdFeB-based melt-spun nanocomposite ribbons have been carried out. Comparison was made between samples treated by rapid thermal annealing and by conventional furnace annealing. Heating rates up to 200 K s{sup -1} were adopted in the rapid thermal processing. It was observed that magnetic hardening can be realized in an annealing time as short as 1 s. Coercivity of 10.2 kOe in the nanocomposites has been obtained by rapid thermal annealing for 1 s, and prolonged annealing did not give any increase in coercivity. Detailed results on the effects of annealing time, temperature and heating rate have been obtained. The dependence of magnetic properties on the annealing parameters has been investigated. Structural characterization revealed that there is a close correlation between magnetic hardening and nanostructured morphology. The coercivity mechanism was also studied by analysing the magnetization minor loops.

  5. Rapid analysis of some rare earth magnets

    International Nuclear Information System (INIS)

    Raoot, K.N.; Raoot, Sarala; Rukmani Desikan, N.

    1978-01-01

    A simple complexometric method for the quick analysis of the constituent elements in some quaternary rare earth magnets of the type RE-Co-Cu-Fe and RE-Ni-Cu-Fe is described. The technique is based on a total titration, subsequent release of EDTA from rare earth with ammonium fluoride and that from copper (II) with ascorbic acid and thiourea followed by determination of the excess and liberated EDTA by lead nitrate in a weak acid medium using xylenol orange indicator. In another, aliquot iron (III) and rare earth are first masked with sodium fluoride, and copper (II) with ascorbic acid and thiourea before cobalt (II) or nickel (II) is estimated by back titration. Iron is calculated by difference. The new method yields accurate and reproducible results with error not exceeding 1%. A set of three samples can conveniently be analysed in two hours. (author)

  6. Rapid analysis of some rare earth magnets

    Energy Technology Data Exchange (ETDEWEB)

    Raoot, K N; Raoot, S; Rukmani Desikan, N [Defence Metallurgical Research Lab., Hyderabad (India)

    1978-12-01

    A simple complexometric method for the quick analysis of the constituent elements in some quaternary rare earth magnets of the type RE-Co-Cu-Fe and RE-Ni-Cu-Fe is described. The technique is based on a total titration, subsequent release of EDTA from rare earth with ammonium fluoride and that from copper (II) with ascorbic acid and thiourea followed by determination of the excess and liberated EDTA by lead nitrate in a weak acid medium using xylenol orange indicator. In another, aliquot iron (III) and rare earth are first masked with sodium fluoride, and copper (II) with ascorbic acid and thiourea before cobalt (II) or nickel (II) is estimated by back titration. Iron is calculated by difference. The new method yields accurate and reproducible results with error not exceeding 1%. A set of three samples can conveniently be analysed in two hours.

  7. TUTORIAL: Focused-ion-beam-based rapid prototyping of nanoscale magnetic devices

    Science.gov (United States)

    Khizroev, S.; Litvinov, D.

    2004-03-01

    In this tutorial, focused-ion-beam (FIB)-based fabrication is considered from a very unconventional angle. FIB is considered not as a fabrication tool that can be used for mass production of electronic devices, similar to optical and E-beam—based lithography, but rather as a powerful tool to rapidly fabricate individual nanoscale magnetic devices for prototyping future electronic applications. Among the effects of FIB-based fabrication of magnetic devices, the influence of Ga+-ion implantation on magnetic properties is presented. With help of magnetic force microscopy (MFM), it is shown that there is a critical doze of ions that a magnetic material can be exposed to without experiencing a change in the magnetic properties. Exploiting FIB from such an unconventional perspective is especially favourable today when the future of so many novel technologies depends on the ability to rapidly fabricate prototype nanoscale magnetic devices. As one of the most illustrative examples, the multi-billion-dollar data storage industry is analysed as the technology field that strongly benefited from implementing FIB in the above-described role. The essential role of FIB in the most recent trend of the industry towards perpendicular magnetic recording is presented. Moreover, other emerging and fast-growing technologies are considered as examples of nanoscale technologies whose future could strongly depend on the implementation of FIB in the role of a nanoscale fabrication tool for rapid prototyping. Among the other described technologies are 'ballistic' magnetoresistance, patterned magnetic media, magnetoresistive RAM (MRAM), and magnetic force microscopy.

  8. The Rapid Ice Sheet Change Observatory (RISCO)

    Science.gov (United States)

    Morin, P.; Howat, I. M.; Ahn, Y.; Porter, C.; McFadden, E. M.

    2010-12-01

    The recent expansion of observational capacity from space has revealed dramatic, rapid changes in the Earth’s ice cover. These discoveries have fundamentally altered how scientists view ice-sheet change. Instead of just slow changes in snow accumulation and melting over centuries or millennia, important changes can occur in sudden events lasting only months, weeks, or even a single day. Our understanding of these short time- and space-scale processes, which hold important implications for future global sea level rise, has been impeded by the low temporal and spatial resolution, delayed sensor tasking, incomplete coverage, inaccessibility and/or high cost of data available to investigators. New cross-agency partnerships and data access policies provide the opportunity to dramatically improve the resolution of ice sheet observations by an order of magnitude, from timescales of months and distances of 10’s of meters, to days and meters or less. Advances in image processing technology also enable application of currently under-utilized datasets. The infrastructure for systematically gathering, processing, analyzing and distributing these data does not currently exist. Here we present the development of a multi-institutional, multi-platform observatory for rapid ice change with the ultimate objective of helping to elucidate the relevant timescales and processes of ice sheet dynamics and response to climate change. The Rapid Ice Sheet Observatory (RISCO) gathers observations of short time- and space-scale Cryosphere events and makes them easily accessible to investigators, media and general public. As opposed to existing data centers, which are structured to archive and distribute diverse types of raw data to end users with the specialized software and skills to analyze them, RISCO focuses on three types of geo-referenced raster (image) data products in a format immediately viewable with commonly available software. These three products are (1) sequences of images

  9. Indigenous people's detection of rapid ecological change.

    Science.gov (United States)

    Aswani, Shankar; Lauer, Matthew

    2014-06-01

    When sudden catastrophic events occur, it becomes critical for coastal communities to detect and respond to environmental transformations because failure to do so may undermine overall ecosystem resilience and threaten people's livelihoods. We therefore asked how capable of detecting rapid ecological change following massive environmental disruptions local, indigenous people are. We assessed the direction and periodicity of experimental learning of people in the Western Solomon Islands after a tsunami in 2007. We compared the results of marine science surveys with local ecological knowledge of the benthos across 3 affected villages and 3 periods before and after the tsunami. We sought to determine how people recognize biophysical changes in the environment before and after catastrophic events such as earthquakes and tsunamis and whether people have the ability to detect ecological changes over short time scales or need longer time scales to recognize changes. Indigenous people were able to detect changes in the benthos over time. Detection levels differed between marine science surveys and local ecological knowledge sources over time, but overall patterns of statistically significant detection of change were evident for various habitats. Our findings have implications for marine conservation, coastal management policies, and disaster-relief efforts because when people are able to detect ecological changes, this, in turn, affects how they exploit and manage their marine resources. © 2014 Society for Conservation Biology.

  10. MAGNETIC FIELD MEASUREMENTS FOR FAST-CHANGING MAGNETIC FIELDS

    International Nuclear Information System (INIS)

    2004-01-01

    Several recent applications for fast ramped magnets have been found that require rapid measurement of the field quality during the ramp. (In one instance, accelerator dipoles will be ramped at 1 T/sec, with measurements needed to the accuracy typically required for accelerators.) We have built and tested a new type of magnetic field measuring system to meet this need. The system consists of 16 stationary pickup windings mounted on a cylinder. The signals induced in the windings in a changing magnetic field are sampled and analyzed to obtain the field harmonics. To minimize costs, printed circuit boards were used for the pickup windings and a combination of amplifiers and ADPs used for the voltage readout system. New software was developed for the analysis. Magnetic field measurements of a model dipole developed for the SIS200 accelerator at GSI are presented. The measurements are needed to insure that eddy currents induced by the fast ramps do not impact the field quality needed for successful accelerator operation

  11. Rapid Change Detection Algorithm for Disaster Management

    Science.gov (United States)

    Michel, U.; Thunig, H.; Ehlers, M.; Reinartz, P.

    2012-07-01

    This paper focuses on change detection applications in areas where catastrophic events took place which resulted in rapid destruction especially of manmade objects. Standard methods for automated change detection prove not to be sufficient; therefore a new method was developed and tested. The presented method allows a fast detection and visualization of change in areas of crisis or catastrophes. While often new methods of remote sensing are developed without user oriented aspects, organizations and authorities are not able to use these methods because of absence of remote sensing know how. Therefore a semi-automated procedure was developed. Within a transferable framework, the developed algorithm can be implemented for a set of remote sensing data among different investigation areas. Several case studies are the base for the retrieved results. Within a coarse dividing into statistical parts and the segmentation in meaningful objects, the framework is able to deal with different types of change. By means of an elaborated Temporal Change Index (TCI) only panchromatic datasets are used to extract areas which are destroyed, areas which were not affected and in addition areas where rebuilding has already started.

  12. Rapid Magnetic Nanobiosensor for the detection of Serratia marcescen

    Science.gov (United States)

    Aljabali, Alaa A. A.; Hussein, Emad; Aljumaili, Omar; Zoubi, Mazhar Al; Altrad, Bahaa; Albatayneh, Khaled; Al-razaq, Mutaz A. Abd

    2018-02-01

    The development of rapid, sensitive, accurate and reliable bacterial detection methods are of keen interest to ensure food safety and hospital security. Therefore, the development of a fast, specific, low-cost and trusted methods is in high demand. Magnetic nanoparticles with their unique material properties have been utilized as a tool for pathogen detection. Here, we present a novel iron oxide nanoparticles labeled with specific targeting antibodies to improve specificity and extend the use of nanoparticles as nanosensors. The results indicated that antibody labeled iron oxide platform that binds specifically to Serriata marcescenst in a straightforward method is very specific and sensitive. The system is capable of rapid and specific detection of various clinically relevant bacterial species, with sensitivity down to single bacteria. The generic platform could be used to identify pathogens for a variety of applications rapidly.

  13. Public health in a rapidly changing world

    Directory of Open Access Journals (Sweden)

    Tatiana I. Andreeva

    2014-06-01

    Full Text Available Several months in 2013 and 2014 have been a hardly predictable time in Ukraine, and the situation is still far from being stable. This made the editorial team of TCPHEE based in Ukraine postpone publishing consecutive issues. However, while the situation still requires practical steps, many aspects including those related to public health require analysis and debate. Thus we invite opinion pieces and studies addressing all different spheres of how public health should function under changing social circumstances. There might be a wide range of such related topics. The most obvious ones are those linked to changing living conditions. Many studies have been undertaken and published with regard to health threats to refugees, people involved in natural or technical disasters (Noji, 2005. Along with environmental health threats, there might be mental health disturbances (World Health Organization, 1992 resulting from long-term strain, losses et cetera. Another important focus is related to changes in health services provision. Crimea, which is a former Ukrainian territory now occupied by the Russian Federation, was among those in Ukraine highly affected with HIV (Dehne, Khodakevich, Hamers, & Schwartlander, 1999. This was responded by several NGOs actively providing harm reduction services to high-risk groups along with methadone substitution therapy to opiate users and antiretroviral medicines to those HIV-infected (Curtis, 2010. However, there are news reports that Russia is going to stop provision of methadone (kommersant.ru, 2014. As opiate substitution programs have been shown an effective approach towards preventing HIV transmission among people who inject drugs (MacArthur et al., 2012, such change in public health policies might affect not only most at risk populations but their partners and population as a whole as well resulting in a rapid spread of HIV. Yet another related topic is that of how health services can be organized at times of

  14. Cosmic rays linked to rapid mid-latitude cloud changes

    Directory of Open Access Journals (Sweden)

    B. A. Laken

    2010-11-01

    Full Text Available The effect of the Galactic Cosmic Ray (GCR flux on Earth's climate is highly uncertain. Using a novel sampling approach based around observing periods of significant cloud changes, a statistically robust relationship is identified between short-term GCR flux changes and the most rapid mid-latitude (60°–30° N/S cloud decreases operating over daily timescales; this signal is verified in surface level air temperature (SLAT reanalysis data. A General Circulation Model (GCM experiment is used to test the causal relationship of the observed cloud changes to the detected SLAT anomalies. Results indicate that the anomalous cloud changes were responsible for producing the observed SLAT changes, implying that if there is a causal relationship between significant decreases in the rate of GCR flux (~0.79 GU, where GU denotes a change of 1% of the 11-year solar cycle amplitude in four days and decreases in cloud cover (~1.9 CU, where CU denotes a change of 1% cloud cover in four days, an increase in SLAT (~0.05 KU, where KU denotes a temperature change of 1 K in four days can be expected. The influence of GCRs is clearly distinguishable from changes in solar irradiance and the interplanetary magnetic field. However, the results of the GCM experiment are found to be somewhat limited by the ability of the model to successfully reproduce observed cloud cover. These results provide perhaps the most compelling evidence presented thus far of a GCR-climate relationship. From this analysis we conclude that a GCR-climate relationship is governed by both short-term GCR changes and internal atmospheric precursor conditions.

  15. Sensitive and rapid immunoassay for parathyroid hormone using magnetic particle labels and magnetic actuation

    NARCIS (Netherlands)

    Dittmer, W.U.; Kievit, de P.; Prins, M.W.J.; Vissers, J.L.M.; Mersch, M.E.C.; Martens, M.F.W.C.

    2008-01-01

    A rapid method for the sensitive detection of proteins using actuated magnetic particle labels, which are measured with a giant magneto-resistive (GMR) biosensor, is described. The technique involves a 1-step sandwich immunoassay with no fluid replacement steps. The various assay binding reactions

  16. Direct measurements of the magnetic entropy change

    DEFF Research Database (Denmark)

    Nielsen, Kaspar Kirstein; Neves Bez, Henrique; von Moos, Lars

    2015-01-01

    An experimental device that can accurately measure the magnetic entropy change, Δs, as a function of temperature, T, and magnetic field, H, is presented. The magnetic field source is in this case a set of counter-rotating concentric Halbach-type magnets, which produce a highly homogeneous applied...... to the ambient are negligible in terms of the calorimetric determination of the magnetic entropy change, while the losses cannot be ignored when correcting for the actual sample temperature. We apply the device to two different types of samples; one is commercial grade Gd, i.e., a pure second-order phase...

  17. Force sensor using changes in magnetic flux

    Science.gov (United States)

    Pickens, Herman L. (Inventor); Richard, James A. (Inventor)

    2012-01-01

    A force sensor includes a magnetostrictive material and a magnetic field generator positioned in proximity thereto. A magnetic field is induced in and surrounding the magnetostrictive material such that lines of magnetic flux pass through the magnetostrictive material. A sensor positioned in the vicinity of the magnetostrictive material measures changes in one of flux angle and flux density when the magnetostrictive material experiences an applied force that is aligned with the lines of magnetic flux.

  18. Rapid treatment-induced brain changes in pediatric CRPS.

    Science.gov (United States)

    Erpelding, Nathalie; Simons, Laura; Lebel, Alyssa; Serrano, Paul; Pielech, Melissa; Prabhu, Sanjay; Becerra, Lino; Borsook, David

    2016-03-01

    To date, brain structure and function changes in children with complex regional pain syndrome (CRPS) as a result of disease and treatment remain unknown. Here, we investigated (a) gray matter (GM) differences between patients with CRPS and healthy controls and (b) GM and functional connectivity (FC) changes in patients following intensive interdisciplinary psychophysical pain treatment. Twenty-three patients (13 females, 9 males; average age ± SD = 13.3 ± 2.5 years) and 21 healthy sex- and age-matched controls underwent magnetic resonance imaging. Compared to controls, patients had reduced GM in the primary motor cortex, premotor cortex, supplementary motor area, midcingulate cortex, orbitofrontal cortex, dorsolateral prefrontal cortex (dlPFC), posterior cingulate cortex, precuneus, basal ganglia, thalamus, and hippocampus. Following treatment, patients had increased GM in the dlPFC, thalamus, basal ganglia, amygdala, and hippocampus, and enhanced FC between the dlPFC and the periaqueductal gray, two regions involved in descending pain modulation. Accordingly, our results provide novel evidence for GM abnormalities in sensory, motor, emotional, cognitive, and pain modulatory regions in children with CRPS. Furthermore, this is the first study to demonstrate rapid treatment-induced GM and FC changes in areas implicated in sensation, emotion, cognition, and pain modulation.

  19. Millennium Ecosystem Assessment: MA Rapid Land Cover Change

    Data.gov (United States)

    National Aeronautics and Space Administration — The Millennium Ecosystem Assessment: MA Rapid Land Cover Change provides data and information on global and regional land cover change in raster format for...

  20. A Magnetic Resonance Measurement Technique for Rapidly Switched Gradient Magnetic Fields in a Magnetic Resonance Tomograph

    Directory of Open Access Journals (Sweden)

    K. Bartušek

    2003-01-01

    Full Text Available This paper describes a method for measuring of the gradient magnetic field in Nuclear Magnetic Resonance (NMR tomography, which is one of the modern medical diagnostic methods. A very important prerequisite for high quality imaging is a gradient magnetic field in the instrument with exactly defined properties. Nuclear magnetic resonance enables us to measure the pulse gradient magnetic field characteristics with high accuracy. These interesting precise methods were designed, realised, and tested at the Institute of Scientific Instruments (ISI of the Academy of Sciences of the Czech Republic. The first of them was the Instantaneous Frequency (IF method, which was developed into the Instantaneous Frequency of Spin Echo (IFSE and the Instantaneous Frequency of Spin Echo Series (IFSES methods. The above named methods are described in this paper and their a comparison is also presented.

  1. Are rapid changes in brain elasticity possible?

    Science.gov (United States)

    Parker, K. J.

    2017-09-01

    Elastography of the brain is a topic of clinical and preclinical research, motivated by the potential for viscoelastic measures of the brain to provide sensitive indicators of pathological processes, and to assist in early diagnosis. To date, studies of the normal brain and of those with confirmed neurological disorders have reported a wide range of shear stiffness and shear wave speeds, even within similar categories. A range of factors including the shear wave frequency, and the age of the individual are thought to have a possible influence. However, it may be that short term dynamics within the brain may have an influence on the measured stiffness. This hypothesis is addressed quantitatively using the framework of the microchannel flow model, which derives the tissue stiffness, complex modulus, and shear wave speed as a function of the vascular and fluid network in combination with the elastic matrix that comprise the brain. Transformation rules are applied so that any changes in the fluid channels or the elastic matrix can be mapped to changes in observed elastic properties on a macroscopic scale. The results are preliminary but demonstrate that measureable, time varying changes in brain stiffness are possible simply by accounting for vasodynamic or electrochemical changes in the state of any region of the brain. The value of this preliminary exploration is to identify possible mechanisms and order-of-magnitude changes that may be testable in vivo by specialized protocols.

  2. Social psychiatry in a rapidly changing world

    Directory of Open Access Journals (Sweden)

    Thomas K. J. Craig

    2016-01-01

    Full Text Available Many societies around the world are experiencing a period of unprecedented change in traditional social roles and customs. Globalisation has contributed to materialism and a me-first individualism that heightens awareness of income inequality that itself is one of the most robust markers of unhappiness in society. Ever increasing urbanisation has driven an erosion of large ‘joint’ family arrangements to be replaced by smaller and relatively isolated nuclear families and single parent living. Mass migration has unmasked deep seated fear and prejudice towards the outsider in society. These global changes are fertile ground for the social conditions that have long been known to be risks for mental illness – poverty, poor quality child care, social isolation and the active discrimination and exclusion of the alien, the physically disabled and mentally ill. While there is little we can do to reverse global change, there is much a social psychiatrist can do to mitigate the effect, ensuring his/her voice is added to other calls for reducing discriminatory practice, promoting evidence-based social interventions such as parenting advice and peer support and ensuring that the success of a treatment is measured not just in terms of symptomatic improvement but in whether it results in an outcome that is valued by the patient.

  3. Sensitive and rapid immunoassay for parathyroid hormone using magnetic particle labels and magnetic actuation.

    Science.gov (United States)

    Dittmer, W U; de Kievit, P; Prins, M W J; Vissers, J L M; Mersch, M E C; Martens, M F W C

    2008-09-30

    A rapid method for the sensitive detection of proteins using actuated magnetic particle labels, which are measured with a giant magneto-resistive (GMR) biosensor, is described. The technique involves a 1-step sandwich immunoassay with no fluid replacement steps. The various assay binding reactions as well as the bound/free separation are entirely controlled by magnetic forces induced by electromagnets above and below the sensor chip. During the assay, particles conjugated with tracer antibodies are actuated through the sample for target capture, and rapidly brought to the sensor surface where they bind to immobilized capture antibodies. Weakly or unbound labels are removed with a magnetic force oriented away from the GMR sensor surface. For the measurement of parathyroid hormone (PTH), a detection limit in the 10 pM range is obtained with a total assay time of 15 min when 300 nm particles are used. The same sensitivity can be achieved in 5 min when 500 nm particles are used. If 500 nm particles are employed in a 15-minute assay, then 0.8 pM of PTH is detectable. The low sample volume, high analytical performance and high speed of the test coupled with the compact GMR biosensor make the system especially suitable for sensitive testing outside of laboratory environments.

  4. Rapid Evaluation of Platelet Function With T2 Magnetic Resonance

    Science.gov (United States)

    Cuker, Adam; Husseinzadeh, Holleh; Lebedeva, Tatiana; Marturano, Joseph E.; Massefski, Walter; Lowery, Thomas J.; Lambert, Michele P.; Abrams, Charles S.; Weisel, John W.

    2016-01-01

    Objectives: The clinical diagnosis of qualitative platelet disorders (QPDs) based on light transmission aggregometry (LTA) requires significant blood volume, time, and expertise, all of which can be barriers to utilization in some populations and settings. Our objective was to develop a more rapid assay of platelet function by measuring platelet-mediated clot contraction in small volumes (35 µL) of whole blood using T2 magnetic resonance (T2MR). Methods: We established normal ranges for platelet-mediated clot contraction using T2MR, used these ranges to study patients with known platelet dysfunction, and then evaluated agreement between T2MR and LTA with arachidonic acid, adenosine diphosphate, epinephrine, and thrombin receptor activator peptide. Results: Blood from 21 healthy donors was studied. T2MR showed 100% agreement with LTA with each of the four agonists and their cognate inhibitors tested. T2MR successfully detected abnormalities in each of seven patients with known QPDs, with the exception of one patient with a novel mutation leading to Hermansky-Pudlak syndrome. T2MR appeared to detect platelet function at similar or lower platelet counts than LTA. Conclusions: T2MR may provide a clinically useful approach to diagnose QPDs using small volumes of whole blood, while also providing new insight into platelet biology not evident using plasma-based platelet aggregation tests. PMID:28028118

  5. Rapid Communication: seniority changing transitions in yrast states ...

    Indian Academy of Sciences (India)

    Bhoomika Maheshwari

    2017-10-26

    Oct 26, 2017 ... Rapid Communication: v = 2 seniority changing ... has been extensively used to understand various system- .... states. This understanding supports the previous inter- ..... Financial support from the Ministry of Human Resource.

  6. Ecosystem stewardship: sustainability strategies for a rapidly changing planet

    Science.gov (United States)

    F. Stuart Chapin; Stephen R. Carpenter; Gary P. Kofinas; Carl Folke; Nick Abel; William C. Clark; Per Olsson; D. Mark Stafford Smith; Brian Walker; Oran R. Young; Fikret Berkes; Reinette Biggs; J. Morgan Grove; Rosamond L. Naylor; Evelyn Pinkerton; Will Steffen; Frederick J. Swanson

    2010-01-01

    Ecosystem stewardship is an action-oriented framework intended to foster the social-ecological sustainability of a rapidly changing planet. Recent developments identify three strategies that make optimal use of current understanding in an environment of inevitable uncertainty and abrupt change: reducing the magnitude of, and exposure and sensitivity to, known stresses...

  7. Rethinking species’ ability to cope with rapid climate change

    DEFF Research Database (Denmark)

    Hof, Christian; Levinsky, Irina; Bastos Araujo, Miguel

    2011-01-01

    Ongoing climate change is assumed to be exceptional because of its unprecedented velocity. However, new geophysical research suggests that dramatic climatic changes during the Late Pleistocene occurred extremely rapid, over just a few years. These abrupt climatic changes may have been even faster...... than contemporary ones, but relatively few continent-wide extinctions of species have been documented for these periods. This raises questions about the ability of extant species to adapt to ongoing climate change. We propose that the advances in geophysical research challenge current views about...... species' ability to cope with climate change, and that lessons must be learned for modelling future impacts of climate change on species....

  8. Transient magnetic field changes in flares

    International Nuclear Information System (INIS)

    Patterson, A.; Zirin, H.

    1981-01-01

    Magnetic changes have been detected with the videomagnetograph (VMG) at Big Bear during two large flares on 1979 November 5. Two kinds of changes were detected in both flares: a decrease in satellite field strength near the locus of the flare and the appearance of strong transient fields during the peak of the flare. We explain why we believe that the observed effects are real and not instrumental and discuss their significance for flare studies

  9. Rapid Fourier space solution of linear partial integro-differential equations in toroidal magnetic confinement geometries

    International Nuclear Information System (INIS)

    McMillan, B.F.; Jolliet, S.; Tran, T.M.; Villard, L.; Bottino, A.; Angelino, P.

    2010-01-01

    Fluctuating quantities in magnetic confinement geometries often inherit a strong anisotropy along the field lines. One technique for describing these structures is the use of a certain set of Fourier components on the tori of nested flux surfaces. We describe an implementation of this approach for solving partial differential equations, like Poisson's equation, where a different set of Fourier components may be chosen on each surface according to the changing safety factor profile. Allowing the resolved components to change to follow the anisotropy significantly reduces the total number of degrees of freedom in the description. This can permit large gains in computational performance. We describe, in particular, how this approach can be applied to rapidly solve the gyrokinetic Poisson equation in a particle code, ORB5 (Jolliet et al. (2007) [5]), with a regular (non-field-aligned) mesh. (authors)

  10. Method for producing rapid pH changes

    Science.gov (United States)

    Clark, J.H.; Campillo, A.J.; Shapiro, S.L.; Winn, K.R.

    A method of initiating a rapid pH change in a solution comprises irradiating the solution with an intense flux of electromagnetic radiation of a frequency which produces a substantial pK change to a compound in solution. To optimize the resulting pH change, the compound being irradiated in solution should have an excited state lifetime substantially longer than the time required to establish an excited state acid-base equilibrium in the solution. Desired pH changes can be accomplished in nanoseconds or less by means of picosecond pulses of laser radiation.

  11. Rapid Communication: v= 2 seniority changing transitions in yrast 3 ...

    Indian Academy of Sciences (India)

    Home; Journals; Pramana – Journal of Physics; Volume 89; Issue 5. Rapid Communication: Δ υ = 2 seniority changing transitions in yrast 3 − states and B ( E 3 ) systematics of Sn isotopes. BHOOMIKA MAHESHWARI SWATI GARG ASHOK KUMAR JAIN. Research Article Volume 89 Issue 5 November 2017 Article ID 75 ...

  12. An integrated micro-chip for rapid detection of magnetic particles

    KAUST Repository

    Gooneratne, Chinthaka P.; Liang, Cai; Giouroudi, Ioanna; Kosel, Jü rgen

    2012-01-01

    This paper proposes an integrated micro-chip for the manipulation and detection of magnetic particles (MPs). A conducting ring structure is used to manipulate MPs toward giant magnetoresistance(GMR) sensing elements for rapid detection

  13. RAPID COMMUNICATION: Magnetic resonance imaging inside metallic vessels

    Science.gov (United States)

    Han, Hui; Balcom, Bruce J.

    2010-10-01

    We introduce magnetic resonance imaging (MRI) measurements inside metallic vessels. Until now, MRI has been unusable inside metallic vessels because of eddy currents in the walls. We have solved the problem and generated high quality images by employing a magnetic field gradient monitoring method. The ability to image within metal enclosures and structures means many new samples and systems are now amenable to MRI. Most importantly this study will form the basis of new MRI-compatible metallic pressure vessels, which will permit MRI of macroscopic systems at high pressure.

  14. Major rapid weight loss induces changes in cardiac repolarization

    DEFF Research Database (Denmark)

    Vedel-Larsen, Esben; Iepsen, Eva Winning; Lundgren, Julie

    2016-01-01

    INTRODUCTION: Obesity is associated with increased all-cause mortality, but weight loss may not decrease cardiovascular events. In fact, very low calorie diets have been linked to arrhythmias and sudden death. The QT interval is the standard marker for cardiac repolarization, but T-wave morphology...... analysis has been suggested as a more sensitive method to identify changes in cardiac repolarization. We examined the effect of a major and rapid weight loss on T-wave morphology. METHODS AND RESULTS: Twenty-six individuals had electrocardiograms (ECG) taken before and after eight weeks of weight loss......A1c (pweight loss induces changes in cardiac repolarization. Monitoring of MCS during calorie restriction makes it possible to detect repolarization changes with higher discriminative power than the QT-interval during major rapid weight...

  15. Magnetization and isothermal magnetic entropy change of a mixed spin-1 and spin-2 Heisenberg superlattice

    Science.gov (United States)

    Xu, Ping; Du, An

    2017-09-01

    A superlattice composed of spin-1 and spin-2 with ABAB … structure was described with Heisenberg model. The magnetizations and magnetic entropy changes under different magnetic fields were calculated by the Green's function method. The magnetization compensation phenomenon could be observed by altering the intralayer exchange interactions and the single-ion anisotropies of spins. Along with the temperature increasing, the system in the absence of magnetization compensation shows normal magnetic entropy change and displays a peak near the critical temperature, and yet the system with magnetization compensation shows normal magnetic entropy change near the compensation temperature but inverse magnetic entropy change near the critical temperature. Finally, we illustrated the reasons of different behaviors of magnetic entropy change by analyzing the contributions of two sublattices to the total magnetic entropy change.

  16. Perceptual classification in a rapidly-changing environment

    OpenAIRE

    Summerfield, Christopher; Behrens, Timothy E.; Koechlin, Etienne

    2011-01-01

    Humans and monkeys can learn to classify perceptual information in a statistically optimal fashion if the functional groupings remain stable over many hundreds of trials, but little is known about categorisation when the environment changes rapidly. Here, we used a combination of computational modelling and functional neuroimaging to understand how humans classify visual stimuli drawn from categories whose mean and variance jumped unpredictably. Models based on optimal learning (Bayesian mode...

  17. The Chinese experience of rapid modernization: sociocultural changes, psychological consequences?

    Directory of Open Access Journals (Sweden)

    Jiahong eSun

    2016-04-01

    Full Text Available Mainland China has undergone profound changes dating back to the nineteenth century, including a contemporary period of rapid modernization that began in the 1980s. The result has been dramatic social, cultural, and economic shifts impacting the daily lives of Chinese people. In this paper, we explore the psychological implications of sociocultural transformation in China, emphasizing two central themes. First, rising individualism: findings from social and developmental psychology suggest that China’s rapid development has been accompanied by ever-increasing adherence to individualistic values. Second, rising rates of depression: findings from psychiatric epidemiology point to increasing prevalence of depression over this same time period, particularly in rural settings. We argue that links between sociocultural and psychological shifts in China can be usefully studied through a cultural psychology lens, emphasizing the mutual constitution of culture, mind, and brain. In particular, we note that the link between social change, individualism, and rising mental illness deserves careful attention. Our review suggests that shifting values and socialization practices shape emotion norms of concealment and display, with implications for depressive symptom presentation. The challenge comes with interpretation. Increasing prevalence rates of depression may indeed be a general response to the rapidity of sociocultural change, or a specific consequence of rising individualism—but may also result from increasingly ‘Western’ patterns of symptom presentation, or improvements in diagnostic practice. We conclude by considering the challenges posed to standard universal models of psychological phenomena.

  18. The Chinese Experience of Rapid Modernization: Sociocultural Changes, Psychological Consequences?

    Science.gov (United States)

    Sun, Jiahong; Ryder, Andrew G.

    2016-01-01

    Mainland China has undergone profound changes dating back to the nineteenth century, including a contemporary period of rapid modernization that began in the 1980s. The result has been dramatic social, cultural, and economic shifts impacting the daily lives of Chinese people. In this paper, we explore the psychological implications of sociocultural transformation in China, emphasizing two central themes. First, rising individualism: findings from social and developmental psychology suggest that China’s rapid development has been accompanied by ever-increasing adherence to individualistic values. Second, rising rates of depression: findings from psychiatric epidemiology point to increasing prevalence of depression over this same time period, particularly in rural settings. We argue that links between sociocultural and psychological shifts in China can be usefully studied through a cultural psychology lens, emphasizing the mutual constitution of culture, mind, and brain. In particular, we note that the link between social change, individualism, and rising mental illness deserves careful attention. Our review suggests that shifting values and socialization practices shape emotion norms of concealment and display, with implications for depressive symptom presentation. The challenge comes with interpretation. Increasing prevalence rates of depression may indeed be a general response to the rapidity of sociocultural change, or a specific consequence of rising individualism—but may also result from increasingly ‘Western’ patterns of symptom presentation, or improvements in diagnostic practice. We conclude by considering the challenges posed to standard universal models of psychological phenomena. PMID:27092093

  19. Sensor for detecting changes in magnetic fields

    Science.gov (United States)

    Praeg, Walter F.

    1981-01-01

    A sensor for detecting changes in the magnetic field of the equilibrium-field coil of a Tokamak plasma device comprises a pair of bifilar wires disposed circumferentially, one inside and one outside the equilibrium-field coil. Each is shorted at one end. The difference between the voltages detected at the other ends of the bifilar wires provides a measure of changing flux in the equilibrium-field coil. This difference can be used to detect faults in the coil in time to take action to protect the coil.

  20. Managing health care organizations in an age of rapid change.

    Science.gov (United States)

    Benjamin, S; al-Alaiwat, S

    1998-03-01

    Health care managers find their work increasingly difficult, due in part to rapid environmental change that plagues organizational life. Management practices and attitudes that may have been appropriate in previous eras are ineffective today. A study was conducted among managers in the Ministry of Health, State of Bahrain, seeking information about current trends in the macro or external environment that affect the Ministry of Health, as well as internal environmental pressures that may be similar or different. This article provides a clear picture of the context in which managers perform their work and offers recommendations for coping with change in dynamic, complex organizations.

  1. Middle Holocene rapid environmental changes and human adaptation in Greece

    Science.gov (United States)

    Lespez, Laurent; Glais, Arthur; Lopez-Saez, José-Antonio; Le Drezen, Yann; Tsirtsoni, Zoï; Davidson, Robert; Biree, Laetitia; Malamidou, Dimitra

    2016-03-01

    Numerous researchers discuss of the collapse of civilizations in response to abrupt climate change in the Mediterranean region. The period between 6500 and 5000 cal yr BP is one of the least studied episodes of rapid climate change at the end of the Late Neolithic. This period is characterized by a dramatic decline in settlement and a cultural break in the Balkans. High-resolution paleoenvironmental proxy data obtained in the Lower Angitis Valley enables an examination of the societal responses to rapid climatic change in Greece. Development of a lasting fluvio-lacustrine environment followed by enhanced fluvial activity is evident from 6000 cal yr BP. Paleoecological data show a succession of dry events at 5800-5700, 5450 and 5000-4900 cal yr BP. These events correspond to incursion of cold air masses to the eastern Mediterranean, confirming the climatic instability of the middle Holocene climate transition. Two periods with farming and pastural activities (6300-5600 and 5100-4700 cal BP) are evident. The intervening period is marked by environmental changes, but the continuous occurrence of anthropogenic taxa suggests the persistence of human activities despite the absence of archaeological evidence. The environmental factors alone were not sufficient to trigger the observed societal changes.

  2. Rapid Immunoenzyme Assay of Aflatoxin B1 Using Magnetic Nanoparticles

    Directory of Open Access Journals (Sweden)

    Alexandr E. Urusov

    2014-11-01

    Full Text Available The main limitations of microplate-based enzyme immunoassays are the prolonged incubations necessary to facilitate heterogeneous interactions, the complex matrix and poorly soluble antigens, and the significant sample dilutions often required because of the presence of organic extractants. This study presents the use of antibody immobilization on the surface of magnetic particles to overcome these limitations in the detection of the mycotoxin, aflatoxin B1. Features of the proposed system are a high degree of nanoparticle dispersion and methodologically simple immobilization of the antibodies by adsorption. Reactions between the immobilized antibodies with native and labeled antigens are conducted in solution, thereby reducing the interaction period to 5 min without impairing the analytical outcome. Adsorption of immunoglobulins on the surface of magnetic nanoparticles increases their stability in aqueous-organic media, thus minimizing the degree of sample dilution required. Testing barley and maize extracts demonstrated a limit of aflatoxin B1 detection equal to 20 pg/mL and total assay duration of 20 min. Using this method, only the 3-fold dilution of the initial methanol/water (60/40 extraction mixture in the microplate wells is necessary. The proposed pseudo-homogeneous approach could be applied toward immunodetection of a wide range of compounds.

  3. Facile Synthesis of Magnetic Mesoporous Hollow Carbon Microspheres for Rapid Capture of Low-Concentration Peptides

    OpenAIRE

    Cheng, Gong; Zhou, Ming-Da; Zheng, Si-Yang

    2014-01-01

    Mesoporous and hollow carbon microspheres embedded with magnetic nanoparticles (denoted as MHM) were prepared via a facile self-sacrificial method for rapid capture of low-abundant peptides from complex biological samples. The morphology, structure, surface property, and magnetism were well-characterized. The hollow magnetic carbon microspheres have a saturation magnetization value of 130.2 emu g?1 at room temperature and a Brunauer?Emmett?Teller specific surface area of 48.8 m2 g?1 with an a...

  4. Development of rapid detection system on BEPC Ⅱ magnet power supply

    International Nuclear Information System (INIS)

    Chen Suying; Zhan Mingchuan; Long Fengli; Ye Weidong

    2014-01-01

    To quickly find the causes of the accelerator unstable or lost beam caused by magnet power supply in Beijing Electron Positron Collider (BEPC Ⅱ) running, the rapid detection system for magnet power supply was developed. The stability of the system in 8 h is about 0.005%, and it can acquire over nearly 500 sets of magnet power supply current values most quickly in 0.33 ms. All data were written to the MySQL database in real time, so as to be able to quickly troubleshoot magnet power supply problem through historical data analysis and comparison. (authors)

  5. On being a scientist in a rapidly changing world.

    Science.gov (United States)

    Mandel, I D

    1996-02-01

    The practice of biological science has changed dramatically since mid-century, reshaped not only by a rapid series of landmark discoveries, but also by governmental directives, institutional policies, and public attitudes. Until 1964, the major influences were the mentor, who provided direction and indoctrination into the culture of science, and in dentistry, the newly established NIDR, which fueled the research engine with an expanding research and training program. The 1965-74 period witnessed the advent of the Institutional Review Board, an increased social involvement of biological scientists, and a recognition of the need for biological and physical safeguards in the conduct of research. The most turbulent years were 1975-89, when there was a confluence of animal rights activism and regulation, growing concerns with scientific fraud and publication malpractice, and the stresses and strains (and opportunities) resulting from the rapid expansion of the academic-industrial complex. The current period is characterized by rapid pace, high volume, and an increased depth and breadth of knowledge-a major change in scale in the conduct of science. It is an exciting time but one in which ethical issues are multiplying. Attention must be paid.

  6. Rapid Structural Design Change Evaluation with AN Experiment Based FEM

    Science.gov (United States)

    Chu, C.-H.; Trethewey, M. W.

    1998-04-01

    The work in this paper proposes a dynamic structural design model that can be developed in a rapid fashion. The approach endeavours to produce a simplified FEM developed in conjunction with an experimental modal database. The FEM is formulated directly from the geometry and connectivity used in an experimental modal test using beam/frame elements. The model sacrifices fine detail for a rapid development time. The FEM is updated at the element level so the dynamic response replicates the experimental results closely. The physical attributes of the model are retained, making it well suited to evaluate the effect of potential design changes. The capabilities are evaluated in a series of computational and laboratory tests. First, a study is performed with a simulated cantilever beam with a variable mass and stiffness distribution. The modal characteristics serve as the updating target with random noise added to simulate experimental uncertainty. A uniformly distributed FEM is developed and updated. The results show excellent results, all natural frequencies are within 0·001% with MAC values above 0·99. Next, the method is applied to predict the dynamic changes of a hardware portal frame structure for a radical design change. Natural frequency predictions from the original FEM differ by as much as almost 18% with reasonable MAC values. The results predicted from the updated model produce excellent results when compared to the actual hardware changes, the first five modal natural frequency difference is around 5% and the corresponding mode shapes producing MAC values above 0·98.

  7. How Rapid Change Affects Deltas in the Arctic Region

    Science.gov (United States)

    Overeem, I.; Bendixen, M.

    2017-12-01

    Deltas form where the river drains into the ocean. Consequently, delta depositional processes are impacted by either changes in the respective river drainage basin or by changes in the regional marine environment. In a warming Arctic region rapid change has occurred over the last few decades in both the terrestrial domain as well as in the marine domain. Important terrestrial controls include 1) change in permafrost possibly destabilizing river banks, 2) strong seasonality of river discharge due to a short melting season, 3) high sediment supply if basins are extensively glaciated, 4) lake outbursts and ice jams favoring river flooding. Whereas in the Arctic marine domain sea ice loss promotes wave and storm surge impact, and increased longshore transport. We here ask which of these factors dominate any morphological change in Arctic deltas. First, we analyze hydrological data to assess change in Arctic-wide river discharge characteristics and timing, and sea ice concentration data to map changes in sea ice regime. Based on this observational analysis we set up a number of scenarios of change. We then model hypothetical small-scale delta formation considering change in these primary controls by setting up a numerical delta model, and combining it dynamically with a permafrost model. We find that for typical Greenlandic deltas changes in river forcing due to ice sheet melt dominate the morphological change, which is corroborated by mapping of delta progradation from aerial photos and satellite imagery. Whereas in other areas, along the North Slope and the Canadian Arctic small deltas are more stable or experienced retreat. Our preliminary coupled model allows us to further disentangle the impact of major forcing factors on delta evolution in high-latitude systems.

  8. Rapid characterization of superconducting wires and tapes in strong pulsed magnetic fields

    International Nuclear Information System (INIS)

    Bockstal, L. van; Keyser, A. de; Deschagt, J.; Hopkins, S.C.; Glowacki, B.A.

    2007-01-01

    A new measurement system for rapid characterization of superconducting wires and tapes is developed. The CryoPulse-BI is a system to provide a direct measurement of critical material parameters for superconducting materials when high long pulsed magnetic fields and strong currents are applied. In the experiments, synchronized magnetic fields up to 30 T and current pulses up to 5 kA are generated with adjustable timing. Varying the magnetic field strength, the current through the sample and the BI timing allows for a thorough characterization of the sample and the determination of critical currents. The rapid cycle time of the experiments yields a rapid and thorough determination of the critical parameters. The method has been tested on low T c as well as high T c materials with the field parallel or perpendicular to the current. The discussion covers the current state of the art including a comparison of our results to classical DC characterization measurements

  9. Repair effect on patterned CoFeB-based magnetic tunneling junction using rapid thermal annealing

    International Nuclear Information System (INIS)

    Wu, K.-M.; Wang, Y.-H.; Chen, Wei-Chuan; Yang, S.-Y.; Shen, Kuei-Hung; Kao, M.-J.; Tsai, M.-J.; Kuo, C.-Y.; Wu, J.-C.; Horng, Lance

    2007-01-01

    Rapid thermal treatment without applying magnetic field reconstructing magnetic property of Co 60 Fe 20 B 20 was studied through magnetoresistance (R-H) measurement. In this paper, we report that the switching behaviors of CoFeB were obviously improved through rapid thermal annealing for only a brief 5 min. The squareness and reproduction of minor R-H loops were enhanced from 100 deg. C to 250 deg. C . Tunneling magnetoresistance (TMR) that is about 35% in the as-etched cells increases up to 44% after 250 deg. C rapid annealing and still shows about 25% TMR even after 400 deg. C treating. Therefore, repair purpose annealing is some what different from crystallizing purpose annealing. Applying magnetic field during repair annealing was not necessary. Brief thermal treatment improves CoFeB switching behavior indeed, and causes less damage at high temperature

  10. Climate engineering and the risk of rapid climate change

    International Nuclear Information System (INIS)

    Ross, Andrew; Damon Matthews, H

    2009-01-01

    Recent research has highlighted risks associated with the use of climate engineering as a method of stabilizing global temperatures, including the possibility of rapid climate warming in the case of abrupt removal of engineered radiative forcing. In this study, we have used a simple climate model to estimate the likely range of temperature changes associated with implementation and removal of climate engineering. In the absence of climate engineering, maximum annual rates of warming ranged from 0.015 to 0.07 deg. C/year, depending on the model's climate sensitivity. Climate engineering resulted in much higher rates of warming, with the temperature change in the year following the removal of climate engineering ranging from 0.13 to 0.76 deg. C. High rates of temperature change were sustained for two decades following the removal of climate engineering; rates of change of 0.5 (0.3,0.1) deg. C/decade were exceeded over a 20 year period with 15% (75%, 100%) likelihood. Many ecosystems could be negatively affected by these rates of temperature change; our results suggest that climate engineering in the absence of deep emissions cuts could arguably constitute increased risk of dangerous anthropogenic interference in the climate system under the criteria laid out in the United Nations Framework Convention on Climate Change.

  11. Theoretical validation for changing magnetic fields of systems of permanent magnets of drum separators

    Science.gov (United States)

    Lozovaya, S. Y.; Lozovoy, N. M.; Okunev, A. N.

    2018-03-01

    This article is devoted to the theoretical validation of the change in magnetic fields created by the permanent magnet systems of the drum separators. In the article, using the example of a magnetic separator for enrichment of highly magnetic ores, the method of analytical calculation of the magnetic fields of systems of permanent magnets based on the Biot-Savart-Laplace law, the equivalent solenoid method, and the superposition principle of fields is considered.

  12. Multi-function ring magnet power supply for rapid-cycling synchrotrons

    International Nuclear Information System (INIS)

    Praeg, W.F.

    1985-01-01

    Ring magnet power supply (RMPS) circuits that produce a wide range of magnet current waveshapes for rapid-cycling synchrotrons (RCS) are described. The shapes range from long flat-tops separated by a biased dual frequency cosine wave to those having a flat-bottom (injection), followed by a lower frequency cosine half wave (acceleration), a flat-top (extraction), and a higher frequency cosine half wave (magnet reset). Applications of these circuits for proposed synchrotrons are outlined. Solid-state switching circuits and the results of proof-of-concept tests are shown. 8 refs., 12 figs

  13. Mobile work: Ergonomics in a rapidly changing work environment.

    Science.gov (United States)

    Honan, Meg

    2015-01-01

    Places of work have been completely transformed by innovations in mobile work tools and ever-present access to internet data. This article characterizes use patterns and provides preliminary considerations for productive and comfortable use of common mobile devices. Two surveys described trends in mobile work. In the first, ergonomics professionals who oversee programs reported common mobile devices, their users and what data is accessed. The second, an end user survey, explored common activities performed on mobile devices, duration of use and locations where mobile work is common. The survey results provide a baseline data point for the status of mobile work in early 2014. Research indicates that additional risks have been introduced to the neck, thumbs and hands when using mobile devices. Possible trends regarding device use and work locations emerge. Intervention studies provide some direction for the practitioner. Practical strategies are outlined to reduce exposure intensity and duration. Contemporary mobile work presents tremendous change and opportunity for ergonomists and researchers to keep pace with fitting the changing models of work to the person. Continued research is needed on current mobile device use patterns to better understand ergonomic risk exposure in this rapidly changing realm.

  14. Spontaneous magnetic alignment by yearling snapping turtles: rapid association of radio frequency dependent pattern of magnetic input with novel surroundings.

    Science.gov (United States)

    Landler, Lukas; Painter, Michael S; Youmans, Paul W; Hopkins, William A; Phillips, John B

    2015-01-01

    We investigated spontaneous magnetic alignment (SMA) by juvenile snapping turtles using exposure to low-level radio frequency (RF) fields at the Larmor frequency to help characterize the underlying sensory mechanism. Turtles, first introduced to the testing environment without the presence of RF aligned consistently towards magnetic north when subsequent magnetic testing conditions were also free of RF ('RF off → RF off'), but were disoriented when subsequently exposed to RF ('RF off → RF on'). In contrast, animals initially introduced to the testing environment with RF present were disoriented when tested without RF ('RF on → RF off'), but aligned towards magnetic south when tested with RF ('RF on → RF on'). Sensitivity of the SMA response of yearling turtles to RF is consistent with the involvement of a radical pair mechanism. Furthermore, the effect of RF appears to result from a change in the pattern of magnetic input, rather than elimination of magnetic input altogether, as proposed to explain similar effects in other systems/organisms. The findings show that turtles first exposed to a novel environment form a lasting association between the pattern of magnetic input and their surroundings. However, under natural conditions turtles would never experience a change in the pattern of magnetic input. Therefore, if turtles form a similar association of magnetic cues with the surroundings each time they encounter unfamiliar habitat, as seems likely, the same pattern of magnetic input would be associated with multiple sites/localities. This would be expected from a sensory input that functions as a global reference frame, helping to place multiple locales (i.e., multiple local landmark arrays) into register to form a global map of familiar space.

  15. Large-scale flows, sheet plumes and strong magnetic fields in a rapidly rotating spherical dynamo

    Science.gov (United States)

    Takahashi, F.

    2011-12-01

    Mechanisms of magnetic field intensification by flows of an electrically conducting fluid in a rapidly rotating spherical shell is investigated. Bearing dynamos of the Eartn and planets in mind, the Ekman number is set at 10-5. A strong dipolar solution with magnetic energy 55 times larger than the kinetic energy of thermal convection is obtained. In a regime of small viscosity and inertia with the strong magnetic field, convection structure consists of a few large-scale retrograde flows in the azimuthal direction and sporadic thin sheet-like plumes. The magnetic field is amplified through stretching of magnetic lines, which occurs typically through three types of flow: the retrograde azimuthal flow near the outer boundary, the downwelling flow of the sheet plume, and the prograde azimuthal flow near the rim of the tangent cylinder induced by the downwelling flow. It is found that either structure of current loops or current sheets is accompanied in each flow structure. Current loops emerge as a result of stretching the magnetic lines along the magnetic field, wheres the current sheets are formed to counterbalance the Coriolis force. Convection structure and processes of magnetic field generation found in the present model are distinct from those in models at larger/smaller Ekman number.

  16. Application of the magnetic fluid as a detector for changing the magnetic field

    Science.gov (United States)

    Zyatkov, D.; Yurchenko, A.; Yurchenko, V.; Balashov, V.

    2018-05-01

    In article the possibility of use of magnetic fluid as a sensitive element for fixing of change of induction of magnetic field in space is considered. Importance of solvable tasks is connected with search of the perspective magnetic substances susceptible to weak magnetic field. The results of a study of the capacitive method for fixing the change in the magnetic field on the basis of a ferromagnetic liquid are presented. The formation of chain structures in the ferrofluid from magnetic particles under the influence of the applied magnetic field leads to a change in the capacitance of the plate condenser. This task has important practical value for development of a magnetosensitive sensor of change of magnetic field.

  17. Thermoresponsive Magnetic Nano-Biosensors for Rapid Measurements of Inorganic Arsenic and Cadmium

    Directory of Open Access Journals (Sweden)

    Isamu Maeda

    2012-10-01

    Full Text Available Green fluorescent protein-tagged sensor proteins, ArsR-GFP and CadC-GFP, have been produced as biosensors for simple and low-cost quantification of As(III or Cd(II. In this study, the sensor protein-promoter DNA complexes were reconstructed on the surfaces of magnetic particles of different sizes. After the surface modification all the particles could be attracted by magnets, and released different amounts of GFP-tagged protein, according to the metal concentrations within 5 min, which caused significant increases in fluorescence. A detection limit of 1 µg/L for As(III and Cd(II in purified water was obtained only with the nanoparticles exhibiting enough magnetization after heat treatment for 1 min. Therefore, thermoresponsive magnetic nano-biosensors offer great advantages of rapidity and sensitivity for the measurement of the toxic metals in drinking water.

  18. Thermoresponsive magnetic nano-biosensors for rapid measurements of inorganic arsenic and cadmium.

    Science.gov (United States)

    Siddiki, Mohammad Shohel Rana; Shimoaoki, Shun; Ueda, Shunsaku; Maeda, Isamu

    2012-10-18

    Green fluorescent protein-tagged sensor proteins, ArsR-GFP and CadC-GFP, have been produced as biosensors for simple and low-cost quantification of As(III) or Cd(II). In this study, the sensor protein-promoter DNA complexes were reconstructed on the surfaces of magnetic particles of different sizes. After the surface modification all the particles could be attracted by magnets, and released different amounts of GFP-tagged protein, according to the metal concentrations within 5 min, which caused significant increases in fluorescence. A detection limit of 1 µg/L for As(III) and Cd(II) in purified water was obtained only with the nanoparticles exhibiting enough magnetization after heat treatment for 1 min. Therefore, thermoresponsive magnetic nano-biosensors offer great advantages of rapidity and sensitivity for the measurement of the toxic metals in drinking water.

  19. Changing atmospheric fallout of magnetic particles recorded in recent ombrotrophic peat sections.

    Science.gov (United States)

    Oldfield, F; Thompson, R; Barber, K E

    1978-02-10

    Magnetic measurements of ombrotrophic peat allow a reconstruction of changes in the past fallout of magnetic particles through the atmosphere. In recent peat profiles from three sites in Britain and Northern Ireland, a marked increase in saturated isothermal remanent magnetization of the peat is recorded in levels which can be shown to postdate the onset of the Industrial Revolution. Furthermore the spatial variation in contemporary isothermal remanent magnetization values is consistent with a recent industrial and urban origin for the bulk of the magnetic minerals present. Pre-Industrial Revolution values are between two and three orders of magnitude lower, suggesting that the natural cosmic and terrestrial sources previously cited for such material have been dominated in recent times by the products of human activity. Magnetic measurements provide a simple, rapid, and nondestructive method of monitoring and differentiating various types of particulate atmospheric fallout for both recent and preindustrial times.

  20. Tailoring the magnetic properties of new Fe-Ni-Co-Al-(Ta,Nb)-B superelastic rapidly quenched microwires

    International Nuclear Information System (INIS)

    Borza, F.; Lupu, N.; Dobrea, V.; Chiriac, H.

    2015-01-01

    Ferromagnetic Fe-Ni-Co-Al-(Ta,Nb)-B microwires with diameters from 170 μm to 50 μm, which possess both superelastic and good magnetic properties, have been prepared by rapid quenching from the melt using the in rotating water spinning technique followed by cold-drawing and ageing. The cold-drawing and annealing processes lead to the initialization of premartensitic phases as confirmed by the X-ray diffraction and scanning transmission electron microscopic investigations, more significantly in the 50 μm cold-drawn microwires. An increase in the coercive field and in the saturation magnetization has been obtained by annealing, more importantly in the case of Nb-containing alloy. Ageing by thermal or current annealing led to the initialization of the superelastic effect. High values of strain of up to 1.8%, very good repeatability under successive loading, and values of superelastic effect of up to 1.2% have been achieved. The structural analysis coupled with the stress-strain data suggests that these materials annealed at 800 °C have superelastic potential at reduced ageing times. The magnetic behavior was found to be easily tailored through both thermal and thermomagnetic treatments with changes in the magnetic parameters which can be contactless detected. The results are important for future applications where both mechanical and magnetic properties matter, i.e., sensing/actuating systems

  1. Lateralized effect of rapid-rate transcranial magnetic stimulation of the prefrontal cortex on mood.

    Science.gov (United States)

    Pascual-Leone, A; Catalá, M D; Pascual-Leone Pascual, A

    1996-02-01

    We studied the effects of rapid-rate transcranial magnetic stimulation (rTMS) of different scalp positions on mood. Ten normal volunteers rated themselves before and after rTMS on five analog scales labeled "Tristeza" (Sadness), "Ansiedad" (Anxiety), "Alegria" (Happiness), "Cansancio" (Tiredness), and "Dolor/Malestar" (Pain/Discomfort). rTMS was applied to the right lateral prefrontal, left prefrontal, or midline frontal cortex in trains of 5 seconds' duration at 10 Hz and 110% of the subject's motor threshold intensity. Each stimulation position received 10 trains separated by a 25-second pause. No clinically apparent mood changes were evoked by rTMS to any of the scalp positions in any subject. However, left prefrontal rTMS resulted in a significant increase in the Sadness ratings (Tristeza) and a significant decrease in the Happiness ratings ("Alegria") as compared with right prefrontal and midfrontal cortex stimulation. These results show differential effects of rTMS of left and right prefrontal cortex stimulation on mood and illustrate the lateralized control of mood in normal volunteers.

  2. Altering plasma sodium concentration rapidly changes blood pressure during haemodialysis.

    Science.gov (United States)

    Suckling, Rebecca J; Swift, Pauline A; He, Feng J; Markandu, Nirmala D; MacGregor, Graham A

    2013-08-01

    Plasma sodium is increased following each meal containing salt. There is an increasing interest in the effects of plasma sodium concentration, and it has been suggested that it may have direct effects on blood pressure (BP) and possibly influences endothelial function. Experimental increases of plasma sodium concentration rapidly raise BP even when extracellular volume falls. Ten patients with end-stage renal failure established on haemodialysis were studied during the first 2 h of dialysis without fluid removal during this period. They were randomized to receive haemodialysis with (i) dialysate sodium concentration prescribed to 135 mmol/L and (ii) 145 mmol/L in random order in a prospective, single-blinded crossover study. BP measurements and blood samples were taken every 30 min. Pre-dialysis sitting BP was 137/76 ± 7/3 mmHg. Lower dialysate sodium concentration (135 mmol/L) reduced plasma sodium concentration [139.49 ± 0.67 to 135.94 ± 0.52 mmol/L (P area under the curve (AUC) 15823.50 ± 777.15 (mmHg)min] compared with 145 mmol/L [AUC 17018.20 ± 1102.17 (mmHg)min], mean difference 1194.70 ± 488.41 (mmHg)min, P < 0.05. There was a significant positive relationship between change in plasma sodium concentration and change in systolic BP. This direct relationship suggests that a fall of 1 mmol/L in plasma sodium concentration would be associated with a 1.7 mmHg reduction in systolic BP (P < 0.05). The potential mechanism for the increase in BP seen with salt intake may be through small but significant changes in plasma sodium concentration.

  3. Planetary Habitability and Rapid Environmental Change: The Biological Perspective

    Science.gov (United States)

    Schulze-Makuch, D.; Fairen, A.; Irwin, L.

    2012-12-01

    Environmental conditions can change drastically and rapidly during the natural history of a planetary body. We have detailed evidence of these dramatic events from Venus, Earth, Mars, and Titan. Most of these occurrences seem to be triggered by astronomical events such as asteroid impacts or supernova explosions; others are triggered by the planet or moon itself (e.g., supervolcano eruptions). The associated question is always how these events affect the habitability of a planet, particularly the origin and presence of life. Under what conditions would such a drastic event be so catastrophic that it would prohibit the origin of life or be so devastating to existing organisms, that life would not be able to recover and be all but extinguished from a planet? Under what conditions would such an event be positive for the evolution of life, for example spurring life via mass extinctions and associated vacant habitats to the invention of new body plans and higher complexity? Here, we provide insights of what we can learn from the natural history of our own planet, which experienced many environmental disasters and abrupt climate changes, from the impact event that created the Moon to the extinction of the dinosaurs. We apply these insights to other planetary bodies and the question about the presence of life. One example is Mars, which underwent drastic environmental changes at the end of the Noachian period. Assuming that microbial life became established on Mars, could it have survived, perhaps by retreating to environmental niches? Life just starting out would have certainly been more vulnerable to extinction. But how far would it have to have evolved to be more resistant to potential extinction events? Would it have to be global in distribution to survive? Another example is Venus. Should Venus be seen as an example where life, which possibly arose in the first few hundred million years when the planet was still in the habitable zone, would have had no chance to

  4. Sudden flux change studies in high field superconducting accelerator magnets

    International Nuclear Information System (INIS)

    Feher, S.; Bordini, B.; Carcagno, R.; Makulski, A.; Orris, D.F.; Pischalnikov, Y.M.; Sylvester, C.; Tartaglia, M.; Tompkins, J.C.; Zlobin, A.V.

    2004-01-01

    As part of the High Field Magnet Program at Fermilab many magnets have been tested which utilize multi strand Rutherford type cable made of state-of-the art Nb 3 Sn strands. During these magnet tests we observed sudden flux changes by monitoring coil voltages and the magnetic field close to the magnets. These flux changes might be linked to magnet instabilities. The voltage spike signals were correlated with quench antenna signals, a strong indication that these are magnet phenomena. With a new high resolution voltage spike detection system, we were able to observe the detailed structure of the spikes. Two fundamentally different signal shapes were distinguished, most likely generated by different mechanisms

  5. Innovation in regulation of rapidly changing health markets.

    Science.gov (United States)

    Bloom, Gerald; Henson, Spencer; Peters, David H

    2014-06-24

    The rapid evolution and spread of health markets across low and middle-income countries (LMICs) has contributed to a significant increase in the availability of health-related goods and services around the world. The support institutions needed to regulate these markets have lagged behind, with regulatory systems that are weak and under-resourced. This paper explores the key issues associated with regulation of health markets in LMICs, and the different goals of regulation, namely quality and safety of care, value for money, social agreement over fair access and financing, and accountability. Licensing, price controls, and other traditional approaches to the regulation of markets for health products and services have played an important role, but they have been of questionable effectiveness in ensuring safety and efficacy at the point of the user in LMICs. The paper proposes a health market systems conceptual framework, using the value chain for the production, distribution and retail of health goods and services, to examine regulation of health markets in the LMIC context. We conclude by exploring the changing context going forwards, laying out implications for future heath market regulation. We argue that the case for new approaches to the regulation of markets for health products and services in LMICs is compelling. Although traditional "command and control" approaches will have a place in the toolkit of regulators, a broader bundle of approaches is needed that is adapted to the national and market-level context of particular LMICs. The implication is that it is not possible to apply standard or single interventions across countries, as approaches proven to work well in one context will not necessarily work well elsewhere.

  6. Changes in the PHOBOS magnet design

    International Nuclear Information System (INIS)

    Shea, J.Y.; Mignerey, A.C.

    1996-01-01

    After more sophisticated simulation and calculation work, it was realized that the design of the PHOBOS magnet could not create a open-quotes field freeclose quotes region for the first four silicon planes for the purpose of tracking. The cut of the pole face was pushed back towards the center of the magnet by 10 cm. The new results from TOSCA were considered acceptable for the purpose of the PHOBOS tracking equipment

  7. Structural stability of hydrogenated amorphous carbon overcoats used in heat-assisted magnetic recording investigated by rapid thermal annealing

    KAUST Repository

    Wang, N.; Komvopoulos, K.; Rose, F.; Marchon, B.

    2013-01-01

    Ultrathin amorphous carbon (a-C) films are extensively used as protective overcoats of magnetic recording media. Increasing demands for even higher storage densities have necessitated the development of new storage technologies, such as heat-assisted magnetic recording (HAMR), which uses laser-assisted heating to record data on high-stability media that can store single bits in extremely small areas (∼1 Tbit/in.2). Because HAMR relies on locally changing the coercivity of the magnetic medium by raising the temperature above the Curie temperature for data to be stored by the magnetic write field, it raises a concern about the structural stability of the ultrathin a-C film. In this study, rapid thermal annealing (RTA) experiments were performed to examine the thermal stability of ultrathin hydrogenated amorphous carbon (a-C:H) films deposited by plasma-enhanced chemical vapor deposition. Structural changes in the a-C:H films caused by RTA were investigated by x-ray photoelectron spectroscopy, Raman spectroscopy, x-ray reflectivity, and conductive atomic force microscopy. The results show that the films exhibit thermal stability up to a maximum temperature in the range of 400-450 °C. Heating above this critical temperature leads to hydrogen depletion and sp 2 clustering. The critical temperature determined by the results of this study represents an upper bound of the temperature rise due to laser heating in HAMR hard-disk drives and the Curie temperature of magnetic materials used in HAMR hard disks. © 2013 American Institute of Physics.

  8. Women in Physics in a Rapidly Changing China

    Science.gov (United States)

    Wu, Ling-An

    2008-03-01

    Despite the upheavals of the 20th century, physics managed to survive quite well in China, where the first woman president of the American Physical Society was born and bred. During the 1950s as a result of policies that emphasized science and engineering, declared equal rights and equal pay for men and women, and assigned jobs to college graduates irrespective of sex, the number of women in physics increased rapidly, many of whom made notable achievements. Since China's opening up over the last thirty years tremendous changes have taken place, and women now face new opportunities as well as challenges in all aspects of society. Whereas physics used to be regarded as the most elite of the sciences, new fields such as computer science, biotechnology and business are now competing for the best students. Compared with other countries the statistics are not bad; in schools and many physics departments the ratio of women teachers may be 30% or higher, but the numbers drop drastically with rank. Moreover, in some research institutions the ratio of female physicists is actually declining, due to retirement of the older generation and fewer successors. Compulsory retirement for women at an earlier age than for men is also a new factor. Conversely, in recent years the ratio of female graduate students enrolling in physics has increased, even reaching 40% in some universities. However, the reasons for this do not bode well: men are not performing so well as women in entrance exams, while the latter are facing increasing discrimination in employment so they have to seek higher degree qualifications. With the further development of China's economy there will be abundant demand for qualified personnel including women with a physics background. It is imperative to actively support the upcoming generation of women physicists and not lose them in the leaky pipeline. The Chinese Physical Society has taken certain positive steps, such as the recent establishment of the Xie Xi

  9. Rapid socio-cultural change and health in the Arctic

    DEFF Research Database (Denmark)

    Bjerregaard, P

    2001-01-01

    The colonization of the circumpolar peoples has had a profound influence on their health. History tells about devastating epidemics and the introduction of alcohol. The last 50 years have witnessed an unprecedented societal development in Greenland and a rapid epidemiological transition. Physical...... health and survival have improved but at the expense of mental health. The incidence of tuberculosis and the infant mortality rate have decreased because of improved socioeconomic conditions and health care. Mental health has deteriorated parallel to the rapid modernization of Greenlandic society...

  10. A big data management platform for rapidly changing environments

    NARCIS (Netherlands)

    Zahedi, P.

    2014-01-01

    Big data is now a reality. Storing, managing, and analyzing very large amount of data is a common challenge in the world of technology where digital content is rapidly growing. In recent years, FEI advanced electron microscopes, with their unsurpassed magnification and resolving power brought an

  11. The change of magnetic properties of minerals and rocks after their microwave heating

    Directory of Open Access Journals (Sweden)

    Brianèin Jaroslav

    2002-03-01

    Full Text Available The possibility of microwaves utilisation in drying processes of different materials (e.g. wood, textiles, coffee, paper, treating of synthetics, glass and ceramic materials, vulcanisation of gum, melting of ferrous and non-ferrous ores, intensification processes of disintegration of raw materials, desulphurization of coal as well as in processes of disposing hazardous wastes is studied. The presented paper describes the influence of microwave radiation on on the change of magnetic properties of minerals and ores. The modification of magnetic properties of valuable components of irradiated ores increases the efficiency of process of their magnetic separation. Changes of magnetic properties of samples were evaluated by measuring the magnetic susceptibility and by X-ray diffraction analysis before and after their microwave heating.Thermal pretreatment of weakly magnetic ores by applying of microwave radiation is tested on the samples of iron spathic ore from the Rudòany deposit (25.1 % of Fe, 5.1 % of SiO2 and the Nižná Slaná ore (31.1 % of Fe, 9.6 % of SiO2. The influence of microwave on a rate of change of iron spathic ore to magnetite depending on the time of heating was observed for a grain size of 0.5 – 1 mm at a constant oven output of 900 W. The weight of tested samples was 100 g. After 10 min. of heating, an essential change of magnetic properties of ore samples from both deposits occurs and after 15 min. a rapid growth of magnetic susceptibility value is observed. This fact testifies about an intensive decomposition of siderite. The achieved values of magnetic susceptibility, results of chemical analyses as well as the X-ray diffraction records of irradiated samples confirmed the formation of new strongly magnetic mineral phases. Finally, after 40 min. of heating, a sintering of grains resulting in agglomerates, accompanied by molten mass creation, were observed.

  12. Rapid detection and purification of sequence specific DNA binding proteins using magnetic separation

    Directory of Open Access Journals (Sweden)

    TIJANA SAVIC

    2006-02-01

    Full Text Available In this paper, a method for the rapid identification and purification of sequence specific DNA binding proteins based on magnetic separation is presented. This method was applied to confirm the binding of the human recombinant USF1 protein to its putative binding site (E-box within the human SOX3 protomer. It has been shown that biotinylated DNA attached to streptavidin magnetic particles specifically binds the USF1 protein in the presence of competitor DNA. It has also been demonstrated that the protein could be successfully eluted from the beads, in high yield and with restored DNA binding activity. The advantage of these procedures is that they could be applied for the identification and purification of any high-affinity sequence-specific DNA binding protein with only minor modifications.

  13. Rapid Assessment of the Ce-Co-Fe-Cu System for Permanent Magnetic Applications

    Science.gov (United States)

    Meng, F.; Chaudhary, R. P.; Gandha, K.; Nlebedim, I. C.; Palasyuk, A.; Simsek, E.; Kramer, M. J.; Ott, R. T.

    2018-04-01

    This work focuses on the rapid synthesis and characterization of quaternary Ce(CoFeCu)5 alloy libraries to assess their potential viability as permanent magnets. Arrays of bulk specimens with controlled compositions were synthesized via laser engineered net shaping (LENS) by feeding different ratios of alloy powders into a melt pool created by a laser. Based on the assessment of the magnetic properties of the LENS printed samples, arc-melted and cast ingots were prepared with varying Fe (5-20 at.%) and Co (60-45 at.%) compositions while maintaining constant Ce (16 at.%) and Cu (19 at.%) content. The evolution of the microstructure and phases with varying chemical compositions and their dependence on magnetic properties are analyzed in as-cast and heat-treated samples. In both the LENS printed and cast samples, we find the best magnetic properties correspond to a predominantly single-phase Ce(CoFeCu)5 microstructure in which high coercivity (H c > 10 kOe) can be achieved without any microstructural refinement.

  14. Design and fabrication of magnetically functionalized flexible micropillar arrays for rapid and controllable microfluidic mixing

    KAUST Repository

    Zhou, BingPu; Xu, Wei; Syed, Ahad; Chau, Yeungyeung; Chen, Longqing; Chew, Basil; Yassine, Omar; Wu, Xiaoxiao; Gao, Yibo; Zhang, Jingxian; Xiao, Xiao; Kosel, Jü rgen; Zhang, Xixiang; Yao, Zhaohui; Wen, Weijia

    2015-01-01

    Magnetically functionalized PDMS-based micropillar arrays have been successfully designed, fabricated and implanted for controllable microfluidic mixing. The arrangement of PDMS micropillar arrays inside the microchannel can be flexibly controlled by an external magnetic field. As a consequence, the flow fields inside the microchannel can be regulated at will via magnetic activation conveniently. When a microchannel is implanted with such micropillar arrays, two microstreams can be mixed easily and controllably upon the simple application of an on/off magnetic signal. Mixing efficiencies based on micropillar arrays with different densities were investigated and compared. It was found that micropillar arrays with higher density (i.e. smaller pillar pitch) would render better mixing performance. Our microfluidic system is capable of generating highly reproducible results within many cycles of mixing/non-mixing conversion. We believe that the simple mixing-triggering method together with rapid and controllable mixing control will be extraordinarily valuable for various biological or chemical applications in the future. This journal is © The Royal Society of Chemistry 2015.

  15. Design and fabrication of magnetically functionalized flexible micropillar arrays for rapid and controllable microfluidic mixing

    KAUST Repository

    Zhou, BingPu

    2015-03-25

    Magnetically functionalized PDMS-based micropillar arrays have been successfully designed, fabricated and implanted for controllable microfluidic mixing. The arrangement of PDMS micropillar arrays inside the microchannel can be flexibly controlled by an external magnetic field. As a consequence, the flow fields inside the microchannel can be regulated at will via magnetic activation conveniently. When a microchannel is implanted with such micropillar arrays, two microstreams can be mixed easily and controllably upon the simple application of an on/off magnetic signal. Mixing efficiencies based on micropillar arrays with different densities were investigated and compared. It was found that micropillar arrays with higher density (i.e. smaller pillar pitch) would render better mixing performance. Our microfluidic system is capable of generating highly reproducible results within many cycles of mixing/non-mixing conversion. We believe that the simple mixing-triggering method together with rapid and controllable mixing control will be extraordinarily valuable for various biological or chemical applications in the future. This journal is © The Royal Society of Chemistry 2015.

  16. Rapid Assessment of the Ce-Co-Fe-Cu System for Permanent Magnetic Applications

    Science.gov (United States)

    Meng, F.; Chaudhary, R. P.; Gandha, K.; Nlebedim, I. C.; Palasyuk, A.; Simsek, E.; Kramer, M. J.; Ott, R. T.

    2018-06-01

    This work focuses on the rapid synthesis and characterization of quaternary Ce(CoFeCu)5 alloy libraries to assess their potential viability as permanent magnets. Arrays of bulk specimens with controlled compositions were synthesized via laser engineered net shaping (LENS) by feeding different ratios of alloy powders into a melt pool created by a laser. Based on the assessment of the magnetic properties of the LENS printed samples, arc-melted and cast ingots were prepared with varying Fe (5-20 at.%) and Co (60-45 at.%) compositions while maintaining constant Ce (16 at.%) and Cu (19 at.%) content. The evolution of the microstructure and phases with varying chemical compositions and their dependence on magnetic properties are analyzed in as-cast and heat-treated samples. In both the LENS printed and cast samples, we find the best magnetic properties correspond to a predominantly single-phase Ce(CoFeCu)5 microstructure in which high coercivity ( H c > 10 kOe) can be achieved without any microstructural refinement.

  17. Evaluation of mechanical properties for spherical magnetic regenerator materials fabricated by rapid solidification process

    International Nuclear Information System (INIS)

    Okamura, M.; Sori, N.; Saito, A.

    1997-01-01

    Various magnetic regenerator materials, such as Er 3 Ni, Er 3 Co and ErNi, are fabricated in the form of a spherical particle by a rapid solidification process. 4 K level refrigeration has been obtained by a GM refrigerator using these materials. However, the magnetic regenerator materials are considered brittle, as they are intermetallic compounds. It is important to evaluate the mechanical properties of these materials to confirm reliability as a regenerator material. In this paper, experimental results of compression and vibration tests for magnetic regenerator materials are described. The technical point of this study is to use spherical particles as test samples. The compressive stress of 20 MPa was applied to these spherical particles and no fractured spheres were observed. Similarly, no fractured spheres were found after the vibration test, in which the maximum acceleration was 30 X 9.8 m/s 2 and the number of vibration times was 1 X 10 6 , insofar as there was no room to stir spherical particles in a regenerator. In practice, the reliability of magnetic regenerator materials has been confirmed by a long-run test of 7,000 h in a usual GM refrigerator

  18. Rapid fluorescence detection of pathogenic bacteria using magnetic enrichment technique combined with magnetophoretic chromatography.

    Science.gov (United States)

    Che, Yulan; Xu, Yi; Wang, Renjie; Chen, Li

    2017-08-01

    A rapid and sensitive analytical method was developed to detect pathogenic bacteria which combined magnetic enrichment, fluorescence labeling with polyethylene glycol (PEG) magnetophoretic chromatography. As pathogenic bacteria usually exist in complex matrixes at low concentration, an efficient enrichment is essential for diagnosis. In order to capture series types of pathogenic bacteria in samples, amino-modified magnetic nanoparticles (Fe 3 O 4 @SiO 2 -NH 2 ) were prepared for efficient enrichment by the electrostatic interaction with pathogenic bacteria. It was shown that the capture efficiency reached up to 95.4% for Escherichia coli (E. coli). Furthermore, quantitative analysis of the bacteria was achieved by using acridine orange (AO) as a fluorescence probe for the captured E. coli due to its ability of staining series types of bacteria and rapid labeling. In order to remove the free magnetic nanoparticles and redundant fluorescent reagent, the labeled suspension was poured into a PEG separation column and was separated by applying an external magnetic field. The presence of 100 cfu mL -1 E. coli could be detected for semi-quantitative analysis by observing the separation column with the naked eye, and the concentration could be further evaluated by fluorescence detection. All the above processes were finished within 80 min. It was demonstrated that a good linear relationship existed between the fluorescence intensity and the concentration of E. coli ranging from 10 2 to 10 6  cfu mL -1 , with a detection limit of 100 cfu mL -1 when E. coli acted as target bacteria. The recovery rate of E. coli was 93.6∼102.0% in tap water and cooked meat samples, and the RSD was lower than 7% (n = 6); the result coincided with the conventional plate count method. Graphical abstract ᅟ.

  19. Observation of magnetic flux generated spontaneously during a rapid quench of superconducting films

    International Nuclear Information System (INIS)

    Maniv, A.; Polturak, E.; Koren, G.

    2003-01-01

    We report observations of spontaneous formation of magnetic flux lines during a rapid quench of YBa 2 Cu 3 O 7-δ films through T c . This effect is predicted according to the Kibble-Zurek mechanism of creation of topological defects of the order parameter during a symmetry-breaking phase transition. Our previous experiment, at a quench rate of 20 K/s, gave null results. In the present experiment, the quench rate was increased to >10 8 K/s. The amount of spontaneous flux increases weakly with the cooling rate

  20. Serial measurement of relative changes in net magnetization, 1

    International Nuclear Information System (INIS)

    Kaneoke, Yoshiki; Furuse, Masahiro; Izawa, Akira.

    1993-01-01

    We assessed to what extent relative changes in net magnetization could be measured with the low field (0.043 T) MR imager. By the procedure to stabilize the whole MR imager hardware, we could measure the minute relative changes of the net magnetization (less than 1%) from the forearm presumably related to blood volume change. This method may be useful to measure physiological changes of blood volume in various human tissues though we need further development of hardware to measure minute relative changes in MR signal intensity with small volume selection. (author)

  1. Rapid deuterium exchange-in time for probing conformational change

    International Nuclear Information System (INIS)

    Dharmasiri, K.; Smith, D.L.

    1995-01-01

    Isotopic exchange of protein backbone amide hydrogens has been used extensively as a sensitive probe of protein structure. One of the salient features of hydrogen exchange is the vast range of exchange rates in one protein. Isotopic exchange methods have been used to study the structural features including protein folding and unfolding (1), functionally different forms of proteins (2), protein-protein complexation (3), and protein stability parameter. Many backbone amide protons that are surface accessible and are not involved in hydrogen bonding undergo rapid deuterium exchange. In order to study, fast exchanging amide protons, fast exchange-in times are necessary

  2. Rapid microwave-assisted synthesis of dextran-coated iron oxide nanoparticles for magnetic resonance imaging.

    Science.gov (United States)

    Osborne, Elizabeth A; Atkins, Tonya M; Gilbert, Dustin A; Kauzlarich, Susan M; Liu, Kai; Louie, Angelique Y

    2012-06-01

    Currently, magnetic iron oxide nanoparticles are the only nanosized magnetic resonance imaging (MRI) contrast agents approved for clinical use, yet commercial manufacturing of these agents has been limited or discontinued. Though there is still widespread demand for these particles both for clinical use and research, they are difficult to obtain commercially, and complicated syntheses make in-house preparation unfeasible for most biological research labs or clinics. To make commercial production viable and increase accessibility of these products, it is crucial to develop simple, rapid and reproducible preparations of biocompatible iron oxide nanoparticles. Here, we report a rapid, straightforward microwave-assisted synthesis of superparamagnetic dextran-coated iron oxide nanoparticles. The nanoparticles were produced in two hydrodynamic sizes with differing core morphologies by varying the synthetic method as either a two-step or single-step process. A striking benefit of these methods is the ability to obtain swift and consistent results without the necessity for air-, pH- or temperature-sensitive techniques; therefore, reaction times and complex manufacturing processes are greatly reduced as compared to conventional synthetic methods. This is a great benefit for cost-effective translation to commercial production. The nanoparticles are found to be superparamagnetic and exhibit properties consistent for use in MRI. In addition, the dextran coating imparts the water solubility and biocompatibility necessary for in vivo utilization.

  3. Rapid microwave-assisted synthesis of dextran-coated iron oxide nanoparticles for magnetic resonance imaging

    International Nuclear Information System (INIS)

    Osborne, Elizabeth A; Atkins, Tonya M; Kauzlarich, Susan M; Gilbert, Dustin A; Liu Kai; Louie, Angelique Y

    2012-01-01

    Currently, magnetic iron oxide nanoparticles are the only nanosized magnetic resonance imaging (MRI) contrast agents approved for clinical use, yet commercial manufacturing of these agents has been limited or discontinued. Though there is still widespread demand for these particles both for clinical use and research, they are difficult to obtain commercially, and complicated syntheses make in-house preparation unfeasible for most biological research labs or clinics. To make commercial production viable and increase accessibility of these products, it is crucial to develop simple, rapid and reproducible preparations of biocompatible iron oxide nanoparticles. Here, we report a rapid, straightforward microwave-assisted synthesis of superparamagnetic dextran-coated iron oxide nanoparticles. The nanoparticles were produced in two hydrodynamic sizes with differing core morphologies by varying the synthetic method as either a two-step or single-step process. A striking benefit of these methods is the ability to obtain swift and consistent results without the necessity for air-, pH- or temperature-sensitive techniques; therefore, reaction times and complex manufacturing processes are greatly reduced as compared to conventional synthetic methods. This is a great benefit for cost-effective translation to commercial production. The nanoparticles are found to be superparamagnetic and exhibit properties consistent for use in MRI. In addition, the dextran coating imparts the water solubility and biocompatibility necessary for in vivo utilization. (paper)

  4. Facile and rapid synthesis of nickel nanowires and their magnetic properties

    International Nuclear Information System (INIS)

    Tang Shaochun; Zheng Zhou; Vongehr, Sascha; Meng Xiangkang

    2011-01-01

    The present work reports a facile and rapid microwave-assisted route to synthesize nickel nanowires with a necklace-like morphology and lengths up to several hundreds of microns. The wires consist of many crystallites with an average size of 25 ± 2 nm. The synthesis does not use templates or magnetic fields and needs only 6 min, which is more than 480 times faster than that needed for Ni wires prepared at 180 °C using conventional heating. Nickel nanostructures with various morphologies including spheres, chains and irregular particles with porous surfaces can also be obtained by adjusting reaction parameters. Polyvinylpyrrolidone (PVP) is found to be vital for the formation of the one-dimensional chains and a high concentration of PVP smoothes their surfaces to result in the appearance of wires. This rapid one-pot procedure combines the formation of nanoparticles, their oriented assembly into chains, and the subsequent shaping of wires. The Ni nanostructures show variable magnetic properties. The prepared nickel wires have a high mechanical stability and exhibit much higher coercivity than bulk nickel, Ni nanoparticles and their aggregations, which promise potential applications in micromechanical sensors, memory devices and other fields.

  5. Policy options to respond to rapid climate change

    NARCIS (Netherlands)

    Swart, R.J.; Marinova, N.A.; Bakker, S.; Tilburg, van X.

    2009-01-01

    Ongoing research on climate change indicates that we cannot rule out the possibility of extreme climatic changes, beyond current IPCC scenarios. The thinking about policy responses to address these risks is still in its infancy. This study explores the possibilities for responding to extreme

  6. San Francisco Bay Area Rapid Transit District (BART) climate change adaptation assessment pilot.

    Science.gov (United States)

    2013-12-01

    The objective of this pilot study was to evaluate the impacts of climate change on the San Francisco Bay Area Rapid Transit District : (BART) infrastructure and to develop and implement adaptation strategies against those impacts. Climate change haza...

  7. Rapid and Efficient Protein Digestion using Trypsin Coated Magnetic Nanoparticles under Pressure Cycles

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Byoungsoo; Lopez-Ferrer, Daniel; Kim, Byoung Chan; Na, Hyon Bin; Park, Yong Il; Weitz, Karl K.; Warner, Marvin G.; Hyeon, Taeghwan; Lee, Sang-Won; Smith, Richard D.; Kim, Jungbae

    2011-01-01

    Trypsin-coated magnetic nanoparticles (EC-TR/NPs), prepared via a simple crosslinking of the enzyme to magnetic nanoparticles, were highly stable and could be easily captured using a magnet after the digestion was complete. EC-TR/NPs showed a negligible loss of trypsin activity after multiple uses and continuous shaking, while a control sample of covalently-attached trypsin on NPs resulted in a rapid inactivation under the same conditions due to the denaturation and autolysis of trypsin. Digestions were carried out on a single model protein, a five protein mixture, and a whole mouse brain proteome, and also compared for digestion at atmospheric pressure and 37 ºC for 12 h, and in combination with pressure cycling technology (PCT) at room temperature for 1 min. In all cases, the EC-TR/NPs performed equally as well or better than free trypsin in terms of the number of peptide/protein identifications and reproducibility across technical replicates. However, the concomitant use of EC-TR/NPs and PCT resulted in very fast (~1 min) and more reproducible digestions.

  8. Velocity dependence of transient hyperfine field at Pt ions rapidly recoiling through magnetized Fe

    International Nuclear Information System (INIS)

    Stuchbery, A.E.; Ryan, C.G.; Bolotin, H.H.

    1981-01-01

    The velocity-dependence of the transient hyperfine magnetic field acting at nuclei of 196 Pt ions rapidly recoiling through thin magnetized Fe was investigated at a number of recoil velocities. The state of interest (2 1 + ) was populated by Coulomb excitation using beams of 80- and 120-MeV 32 S and 150- and 220-MeV 58 Ni ions. The 2 1 + →0 1 + γ-ray angular distribution precession measurements were carried out in coincidence with backscattered projectiles. From these results, the strength of the transient field acting on Pt ions recoiling through magnetized Fe with average velocities in the extended range 2.14<=v/vsub(o)<=4.82 (vsub(o) = c/137) was found to be consistent with a linear velocity dependence and to be incompatible with the specific vsup(0.45+-0.18) dependence which has been previously reported to account well for all ions in the mass range from oxygen through samarium. This seemingly singular behaviour for Pt and other ions in the Pt mass vicinity is discussed

  9. Evidence-based medicine in rapidly changing technologies

    DEFF Research Database (Denmark)

    Schroeder, Torben Veith

    2008-01-01

    Evidence-based medicine (EBM) is not a randomised controlled trial (RCT), but EBM seeks to apply evidence gained from scientific methods - which could be RCT - to daily medical practice. Any surgical treatment reflects a certain development technically as well as skills based. The procedure may....... Special considerations should be given in rapidly developing fields. If started too early the resulting comparison will likely turn out to be irrelevant because the new technology is not fully developed, not mastered or the device may have undergone major modifications rendering the results obsolete....... On the other hand, if started too late there is a chance that data may be lost because the technology has already been introduced into the daily clinics and physicians may be unwilling to recruit patients. Or the opposite, that the technique may have been rejected without a proper trial. In this situation...

  10. Recommendations for Guidelines for Environment-Specific Magnetic-Field Measurements, Rapid Program Engineering Project #2

    Energy Technology Data Exchange (ETDEWEB)

    Electric Research and Management, Inc.; IIT Research Institute; Magnetic Measurements; Survey Research Center, University of California; T. Dan Bracken, Inc.

    1997-03-11

    The purpose of this project was to document widely applicable methods for characterizing the magnetic fields in a given environment, recognizing the many sources co-existing within that space. The guidelines are designed to allow the reader to follow an efficient process to (1) plan the goals and requirements of a magnetic-field study, (2) develop a study structure and protocol, and (3) document and carry out the plan. These guidelines take the reader first through the process of developing a basic study strategy, then through planning and performing the data collection. Last, the critical factors of data management, analysis reporting, and quality assurance are discussed. The guidelines are structured to allow the researcher to develop a protocol that responds to specific site and project needs. The Research and Public Information Dissemination Program (RAPID) is based on exposure to magnetic fields and the potential health effects. Therefore, the most important focus for these magnetic-field measurement guidelines is relevance to exposure. The assumed objective of an environment-specific measurement is to characterize the environment (given a set of occupants and magnetic-field sources) so that information about the exposure of the occupants may be inferred. Ideally, the researcher seeks to obtain complete or "perfect" information about these magnetic fields, so that personal exposure might also be modeled perfectly. However, complete data collection is not feasible. In fact, it has been made more difficult as the research field has moved to expand the list of field parameters measured, increasing the cost and complexity of performing a measurement and analyzing the data. The guidelines address this issue by guiding the user to design a measurement protocol that will gather the most exposure-relevant information based on the locations of people in relation to the sources. We suggest that the "microenvironment" become the base unit of area in a study, with

  11. Rapid prototyping of magnetic tunnel junctions with focused ion beam processes

    International Nuclear Information System (INIS)

    Persson, Anders; Thornell, Greger; Nguyen, Hugo

    2010-01-01

    Submicron-sized magnetic tunnel junctions (MTJs) are most often fabricated by time-consuming and expensive e-beam lithography. From a research and development perspective, a short lead time is one of the major concerns. Here, a rapid process scheme for fabrication of micrometre size MTJs with focused ion beam processes is presented. The magnetic properties of the fabricated junctions are investigated in terms of magnetic domain structure, tunnelling magnetoresistance (TMR) and coercivity, with extra attention given to the effect of Ga implantation from the ion beam. In particular, the effect of the implantation on the minimum junction size and the magnetization of the sensing layer are studied. In the latter case, magnetic force microscopy and micromagnetic simulations, with the object-oriented micromagnetic framework (OOMMF), are used to study the magnetization reversal. The fabricated junctions show considerable coercivity both along their hard and easy axes. Interestingly, the sensing layer exhibits two remanent states: one with a single and one with a double domain. The hard axis TMR loop has kinks at about ±20 mT which is attributed to a non-uniform lateral coercivity, where the rim of the junctions, which is subjected to Ga implantation from the flank of the ion beam, is more coercive than the unirradiated centre. The width of the coercive rim is estimated to be 160 nm from the hard axis TMR loop. The easy axis TMR loop shows more coercivity than an unirradiated junction and, this too, is found to stem from the coercive rim, as seen from the simulations. It is concluded that the process scheme has three major advantages. Firstly, it has a high lateral and depth resolution—the depth resolution is enhanced by end point detection—and is capable of making junctions of sizes down towards the limit set by the width of the irradiated rim. Secondly, the most delicate process steps are performed in the unbroken vacuum enabling the use of materials prone to

  12. Managing in the rapidly changing context of higher education: a ...

    African Journals Online (AJOL)

    Besides the rate of change in the sector there are also, as seen from the continuous media coverage, a number of universities and technikons in some form of financial or leadership crisis. Over the past years one of the main reasons given for these crises was outstanding student fees. However, the reasons now alluded to ...

  13. Alveolar bone changes after asymmetric rapid maxillary expansion.

    Science.gov (United States)

    Akin, Mehmet; Baka, Zeliha Muge; Ileri, Zehra; Basciftci, Faruk Ayhan

    2015-09-01

    To quantitatively evaluate the effects of asymmetric rapid maxillary expansion (ARME) on cortical bone thickness and buccal alveolar bone height (BABH), and to determine the formation of dehiscence and fenestration in the alveolar bone surrounding the posterior teeth, using cone-beam computed tomography (CBCT). The CBCT records of 23 patients with true unilateral posterior skeletal crossbite (10 boys, 14.06 ± 1.08 years old, and 13 girls, 13.64 ± 1.32 years old) who had undergone ARME were selected from our clinic archives. The bonded acrylic ARME appliance, including an occlusal stopper, was used on all patients. CBCT records had been taken before ARME (T1) and after the 3-month retention period (T2). Axial slices of the CBCT images at 3 vertical levels were used to evaluate the buccal and palatal aspects of the canines, first and second premolars, and first molars. Paired samples and independent sample t-tests were used for statistical comparison. The results suggest that buccal cortical bone thickness of the affected side was significantly more affected by the expansion than was the unaffected side (P ARME significantly reduced the BABH of the canines (P ARME also increased the incidence of dehiscence and fenestration on the affected side. ARME may quantitatively decrease buccal cortical bone thickness and height on the affected side.

  14. Planetary health: protecting human health on a rapidly changing planet.

    Science.gov (United States)

    Myers, Samuel S

    2018-12-23

    The impact of human activities on our planet's natural systems has been intensifying rapidly in the past several decades, leading to disruption and transformation of most natural systems. These disruptions in the atmosphere, oceans, and across the terrestrial land surface are not only driving species to extinction, they pose serious threats to human health and wellbeing. Characterising and addressing these threats requires a paradigm shift. In a lecture delivered to the Academy of Medical Sciences on Nov 13, 2017, I describe the scale of human impacts on natural systems and the extensive associated health effects across nearly every dimension of human health. I highlight several overarching themes that emerge from planetary health and suggest advances in the way we train, reward, promote, and fund the generation of health scientists who will be tasked with breaking out of their disciplinary silos to address this urgent constellation of health threats. I propose that protecting the health of future generations requires taking better care of Earth's natural systems. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Magnetohydrodynamic pressure drop in a quickly changing magnetic field

    International Nuclear Information System (INIS)

    Xu, Z.Y.; Chen, J.M.; Qian, J.P.; Jiang, W.H.; Pan, C.J.; Li, W.Z.

    1995-01-01

    The magnetohydrodynamic (MHD) pressure drop of 22 Na 78 K flow in a circular duct was measured under a quickly changing magnetic field. The MHD pressure drop reduced with time as the magnetic field strength decreased. However, the dimensionless pressure drop gradient varied with the interaction parameter and had a higher value in the middle of the range of values of the interaction parameter. Therefore, a quickly changing magnetic field is harmful to the structural material in a liquid metal self-cooled blanket of a fusion reactor, since the greater pressure drop gradient may cause a larger stress in the blanket. This is even more harmful if the magnetic field strength decreases very quickly or its distribution in space is greatly non-uniform. (orig.)

  16. Doppler-Zeeman Mapping of the Rapidly Rotating Magnetic CP Star HD37776

    Science.gov (United States)

    Khokhlova, V. L.; Vasilchenko, D. V.; Stepanov, V. V.; Romanyuk, I. I.

    2000-03-01

    We present the results of our analysis of magnetic-field configuration and abundance anomalies on the surface of the rapidly rotating, chemically peculiar helium-strong variable B2 V star HD37776 with unresolved Zeeman components of spectral lines. Simultaneous inversion of the observed Stokes I and V profiles, which realizes the method of Doppler-Zeeman mapping (Vasilchenko et al. 1996), has been applied for the first time. Spectroscopic observations were carried out with the Main stellar spectrograph of the 6-m Special Astrophysical Observatory telescope equipped with a Zeeman analyzer and a CCD array, which allowed spectra in right- and left-hand circularly polarized light to be taken simultaneously at a signal-to-noise ratio S/N > 200 (Romanyuk et al. 1999). The profile width of winged spectral lines (reaching 5 A) is determined by Zeeman line splitting; however, the observed Zeeman components are blurred and unresolved because of the rapid stellar rotation. When solving the inverse problem, we sought for the magnetic-field configuration in the form of a combination of arbitrarily oriented dipole, quadrupole, and octupole placed at the stellar center. The observed Stokes I and V profiles for eight spectral lines of He, OII, AlIII, SiIII, and FeIII averaged over the visible stellar surface were used as input data. We constructed a model of the magnetic field from the condition of coincidence of magnetic maps obtained from different lines of different chemical elements and from the condition of a minimum profile residual. This model is a combination of centered coaxial dipole and quadrupole with the dominant quadrupole component at 30 deg < i < 50 deg, beta = 40 deg, and a maximum surface field strength H_s = 60 kG. A comparison of our abundance maps with the field configuration shows that the He concentration is at a maximum in the regions of maximum radial field, while the maximum concentrations of O, Al, Si, and Fe coincide with the regions of maximum

  17. RAPIDLY-SOLIDIFIED PERMANENT MAGNET MATERIALS: FACTORS AFFECTING QUENCHABILITY AND MAGNETIC PROPERTIES IN Nd2Fe14B

    International Nuclear Information System (INIS)

    LEWIS, L.H.; KRAMER, M.J.; MCCALLUM, R.W.; BRANAGAN, D.J.

    1999-01-01

    Insight into the solidification behavior of Nd 2 Fe 14 B-based materials processed by rapid solidification techniques has been obtained by a systematic experimental study of the Curie temperatures of selected phases found in these materials. Nd 2 Fe 14 B-based materials fabricated by two disparate rapid solidification techniques, inert gas atomization (IGA) and melt-spinning, has been studied. The compositions of the starting materials have been altered with additions of the refractory elements Ti and C which are known to alter the solidification behavior of these materials. Special emphasis has been placed on trying to understand the effect of alloying additions upon the nature of the quenched glass, the distribution of the elemental additions within the Nd 2 Fe 14 B lattice and the evolution of the elemental partitioning with quench rate and annealing condition. The experimental Curie temperature data obtained using thermal analysis methods from the particles produced by gas-atomization is consistent with both an ejection of quenched-in refractory species from the crystalline Nd 2 Fe 14 B lattice and with increased crystallographic order as particle size, and hence grain size, increases. Magnetic ac susceptibility measurements performed on nominally-amorphous Nd 2 Fe 14 B ribbons produced by melt-spinning indicate a decrease of the Curie temperature with increasing quench rate, a result that may be attributed either to the degree of Ti/C retention in the glass or to the degree of disorder in the glass, independent of Ti/C retention

  18. Rapid Detection of Ricin in Serum Based on Cu-Chelated Magnetic Beads Using Mass Spectrometry

    Science.gov (United States)

    Zhao, Yong-Qiang; Song, Jian; Wang, Hong-Li; Xu, Bin; Liu, Feng; He, Kun; Wang, Na

    2016-04-01

    The protein toxin ricin obtained from castor bean plant (Ricinus communis) seeds is a potent biological warfare agent due to its ease of availability and acute toxicity. In this study, we demonstrated a rapid and simple method to detect ricin in serum in vitro. The ricin was mixed with serum and digested by trypsin, then all the peptides were efficiently extracted using Cu-chelated magnetic beads and were detected with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The specific ricin peptides were identified by Nanoscale Ultra Performance liquid chromatography coupled to tandem mass spectrometry according to their sequences. The assay required 2.5 hours, and a characteristic peptide could be detected down to 4 ng/μl and used as a biomarker to detect ricin in serum. The high sensitivity and simplicity of the procedure makes it valuable in clinical practice.

  19. A multichannel magnetic β-ray spectrometer for rapid measurements of electron spectra

    International Nuclear Information System (INIS)

    Kariya, Komyo; Morikawa, Kaoru.

    1989-01-01

    In order to make the magnetic β-ray spectrometer suitable for rapid measurements of electron spectra with short-lived nuclides, twelve small GM counters have been arrayed along the focal plane of a 180deg focusing flat type design. All the signal pulses from each one of these detectors are mixed together onto a single cable. By means of multichannel PHA, each pulse can be traced back to the specific detector which sent it out. In order to avoid time consuming evacuation procedures, the sample source is placed outside a thin window of the preevacuated analyzer chamber. By the use of this multichannel spectrometer a β-ray spectrum with maximum energy up to about 10 MeV can be measured within 1 min or so. Electron spectra measured with 113m In, 119m In and 144 Pr source are shown. (author)

  20. An integrated micro-chip for rapid detection of magnetic particles

    KAUST Repository

    Gooneratne, Chinthaka P.

    2012-03-09

    This paper proposes an integrated micro-chip for the manipulation and detection of magnetic particles (MPs). A conducting ring structure is used to manipulate MPs toward giant magnetoresistance(GMR) sensing elements for rapid detection. The GMRsensor is fabricated in a horseshoe shape in order to detect the majority of MPs that are trapped around the conducting structure. The GMR sensing elements are connected in a Wheatstone bridge circuit topology for optimum noise suppression. Full fabrication details of the micro-chip, characterization of the GMRsensors, and experimental results with MPs are presented in this paper. Experimental results showed that the micro-chip can detect MPs from low concentration samples after they were guided toward the GMRsensors by applying current to the conducting ring structure.

  1. Rapid changes in gene expression direct rapid shifts in intestinal form and function in the Burmese python after feeding.

    Science.gov (United States)

    Andrew, Audra L; Card, Daren C; Ruggiero, Robert P; Schield, Drew R; Adams, Richard H; Pollock, David D; Secor, Stephen M; Castoe, Todd A

    2015-05-01

    Snakes provide a unique and valuable model system for studying the extremes of physiological remodeling because of the ability of some species to rapidly upregulate organ form and function upon feeding. The predominant model species used to study such extreme responses has been the Burmese python because of the extreme nature of postfeeding response in this species. We analyzed the Burmese python intestine across a time series, before, during, and after feeding to understand the patterns and timing of changes in gene expression and their relationship to changes in intestinal form and function upon feeding. Our results indicate that >2,000 genes show significant changes in expression in the small intestine following feeding, including genes involved in intestinal morphology and function (e.g., hydrolases, microvillus proteins, trafficking and transport proteins), as well as genes involved in cell division and apoptosis. Extensive changes in gene expression occur surprisingly rapidly, within the first 6 h of feeding, coincide with changes in intestinal morphology, and effectively return to prefeeding levels within 10 days. Collectively, our results provide an unprecedented portrait of parallel changes in gene expression and intestinal morphology and physiology on a scale that is extreme both in the magnitude of changes, as well as in the incredibly short time frame of these changes, with up- and downregulation of expression and function occurring in the span of 10 days. Our results also identify conserved vertebrate signaling pathways that modulate these responses, which may suggest pathways for therapeutic modulation of intestinal function in humans. Copyright © 2015 the American Physiological Society.

  2. SUN-LIKE MAGNETIC CYCLES IN THE RAPIDLY ROTATING YOUNG SOLAR ANALOG HD 30495

    International Nuclear Information System (INIS)

    Egeland, Ricky; Metcalfe, Travis S.; Hall, Jeffrey C.; Henry, Gregory W.

    2015-01-01

    A growing body of evidence suggests that multiple dynamo mechanisms can drive magnetic variability on different timescales, not only in the Sun but also in other stars. Many solar activity proxies exhibit a quasi-biennial (∼2 year) variation, which is superimposed upon the dominant 11 year cycle. A well-characterized stellar sample suggests at least two different relationships between rotation period and cycle period, with some stars exhibiting long and short cycles simultaneously. Within this sample, the solar cycle periods are typical of a more rapidly rotating star, implying that the Sun might be in a transitional state or that it has an unusual evolutionary history. In this work, we present new and archival observations of dual magnetic cycles in the young solar analog HD 30495, a ∼1 Gyr old G1.5 V star with a rotation period near 11 days. This star falls squarely on the relationships established by the broader stellar sample, with short-period variations at ∼1.7 years and a long cycle of ∼12 years. We measure three individual long-period cycles and find durations ranging from 9.6 to 15.5 years. We find the short-term variability to be intermittent, but present throughout the majority of the time series, though its occurrence and amplitude are uncorrelated with the longer cycle. These essentially solar-like variations occur in a Sun-like star with more rapid rotation, though surface differential rotation measurements leave open the possibility of a solar equivalence

  3. Rapid adaptive responses to climate change in corals

    KAUST Repository

    Torda, Gergely; Donelson, Jennifer M.; Aranda, Manuel; Barshis, Daniel J.; Bay, Line; Berumen, Michael L.; Bourne, David G.; Cantin, Neal; Foret, Sylvain; Matz, Mikhail; Miller, David J.; Moya, Aurelie; Putnam, Hollie M.; Ravasi, Timothy; van Oppen, Madeleine J. H.; Thurber, Rebecca Vega; Vidal-Dupiol, Jeremie; Voolstra, Christian R.; Watson, Sue-Ann; Whitelaw, Emma; Willis, Bette L.; Munday, Philip L.

    2017-01-01

    Pivotal to projecting the fate of coral reefs is the capacity of reef-building corals to acclimatize and adapt to climate change. Transgenerational plasticity may enable some marine organisms to acclimatize over several generations and it has been hypothesized that epigenetic processes and microbial associations might facilitate adaptive responses. However, current evidence is equivocal and understanding of the underlying processes is limited. Here, we discuss prospects for observing transgenerational plasticity in corals and the mechanisms that could enable adaptive plasticity in the coral holobiont, including the potential role of epigenetics and coral-associated microbes. Well-designed and strictly controlled experiments are needed to distinguish transgenerational plasticity from other forms of plasticity, and to elucidate the underlying mechanisms and their relative importance compared with genetic adaptation.

  4. Rapid changes in the gut microbiome during human evolution.

    Science.gov (United States)

    Moeller, Andrew H; Li, Yingying; Mpoudi Ngole, Eitel; Ahuka-Mundeke, Steve; Lonsdorf, Elizabeth V; Pusey, Anne E; Peeters, Martine; Hahn, Beatrice H; Ochman, Howard

    2014-11-18

    Humans are ecosystems containing trillions of microorganisms, but the evolutionary history of this microbiome is obscured by a lack of knowledge about microbiomes of African apes. We sequenced the gut communities of hundreds of chimpanzees, bonobos, and gorillas and developed a phylogenetic approach to reconstruct how present-day human microbiomes have diverged from those of ancestral populations. Compositional change in the microbiome was slow and clock-like during African ape diversification, but human microbiomes have deviated from the ancestral state at an accelerated rate. Relative to the microbiomes of wild apes, human microbiomes have lost ancestral microbial diversity while becoming specialized for animal-based diets. Individual wild apes cultivate more phyla, classes, orders, families, genera, and species of bacteria than do individual humans across a range of societies. These results indicate that humanity has experienced a depletion of the gut flora since diverging from Pan.

  5. Rapid adaptive responses to climate change in corals

    KAUST Repository

    Torda, Gergely

    2017-09-01

    Pivotal to projecting the fate of coral reefs is the capacity of reef-building corals to acclimatize and adapt to climate change. Transgenerational plasticity may enable some marine organisms to acclimatize over several generations and it has been hypothesized that epigenetic processes and microbial associations might facilitate adaptive responses. However, current evidence is equivocal and understanding of the underlying processes is limited. Here, we discuss prospects for observing transgenerational plasticity in corals and the mechanisms that could enable adaptive plasticity in the coral holobiont, including the potential role of epigenetics and coral-associated microbes. Well-designed and strictly controlled experiments are needed to distinguish transgenerational plasticity from other forms of plasticity, and to elucidate the underlying mechanisms and their relative importance compared with genetic adaptation.

  6. Rapid further heating of tokamak plasma by fast-rising magnetic pulse

    International Nuclear Information System (INIS)

    Inoue, N.; Nihei, H.; Yamazaki, K.; Ichimura, M.; Morikawa, J.; Hoshino, K.; Uchida, T.

    1977-01-01

    The object of the experiment was to study the rapid further heating of a tokamak plasma and its influence on confinement. For this purpose, a high-voltage theta-pinch pulse was applied to a tokamak plasma and production of a high-temperature (keV) plasma was ensured within a microsecond. The magnetic pulse is applied at the plasma current maximum parallel or antiparallel to the study toroidal field. In either case, the pulsed field quickly penetrates the plasma and the plasma resistivity estimated from the penetration time is about 100 times larger than the classical. A burst of energetic neutrals of approximately 1 μs duration was observed and the energy distribution had two components of the order of 1 keV and 0.1 keV in the antiparallel case. Doppler broadening measurement shows heating of ions to a temperature higher than 200 eV; however, the line profile is not always Maxwellian distribution. The X-rays disappear at the moment of applying the magnetic pulse and reappear about 100 μs later with an intensive burst, while both energy levels are the same (approximately 100 keV). (author)

  7. Lock-in thermography as a rapid and reproducible thermal characterization method for magnetic nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Lemal, Philipp; Geers, Christoph; Monnier, Christophe A.; Crippa, Federica; Daum, Leopold; Urban, Dominic A.; Rothen-Rutishauser, Barbara [Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, CH-1700 Fribourg (Switzerland); Bonmarin, Mathias, E-mail: mathias.bonmarin@zhaw.ch [Institute of Computational Physics, Zurich University of Applied Sciences, Technikumstrasse 9, 8400 Winterthur (Switzerland); Petri-Fink, Alke, E-mail: alke.fink@unifr.ch [Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, CH-1700 Fribourg (Switzerland); Chemistry Department, University of Fribourg, Chemin du Museé 9, CH-1700 Fribourg (Switzerland); Moore, Thomas L., E-mail: thomaslee.moore@unifr.ch [Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, CH-1700 Fribourg (Switzerland)

    2017-04-01

    Lock-in thermography (LIT) is a sensitive imaging technique generally used in engineering and materials science (e.g. detecting defects in composite materials). However, it has recently been expanded for investigating the heating power of nanomaterials, such as superparamagnetic iron oxide nanoparticles (SPIONs). Here we implement LIT as a rapid and reproducible method that can evaluate the heating potential of various sizes of SPIONs under an alternating magnetic field (AMF), as well as the limits of detection for each particle size. SPIONs were synthesized via thermal decomposition and stabilized in water via a ligand transfer process. Thermographic measurements of SPIONs were made by stimulating particles of varying sizes and increasing concentrations under an AMF. Furthermore, a commercially available SPION sample was included as an external reference. While the size dependent heating efficiency of SPIONs has been previously described, our objective was to probe the sensitivity limits of LIT. For certain size regimes it was possible to detect signals at concentrations as low as 0.1 mg Fe/mL. Measuring at different concentrations enabled a linear regression analysis and extrapolation of the limit of detection for different size nanoparticles. - Highlights: • A multi-sample screening assessment of magnetic nanoparticle thermal characteristics is shown via lock-in thermography. • Lower concentration limit of nanoparticle detection based on particle size is proposed. • A commercially available reference sample indicates the stability and reproducibility of LIT.

  8. A magnetic particles-based chemiluminescence enzyme immunoassay for rapid detection of ovalbumin.

    Science.gov (United States)

    Feng, Xiao-Li; Ren, Hong-Lin; Li, Yan-Song; Hu, Pan; Zhou, Yu; Liu, Zeng-Shan; Yan, Dong-Ming; Hui, Qi; Liu, Dong; Lin, Chao; Liu, Nan-Nan; Liu, Yan-Yan; Lu, Shi-Ying

    2014-08-15

    Egg allergy is an important public health and safety concern, so quantification and administration of food or vaccines containing ovalbumin (OVA) are urgently needed. This study aimed to establish a rapid and sensitive magnetic particles-chemiluminescence enzyme immunoassay (MPs-CLEIA) for the determination of OVA. The proposed method was developed on the basis of a double antibodies sandwich immunoreaction and luminol-H2O2 chemiluminescence system. The MPs served as both the solid phase and separator, the anti-OVA MPs-coated polyclonal antibodies (pAbs) were used as capturing antibody, and the horseradish peroxidase (HRP)-labeled monoclonal antibody (mAb) was taken as detecting antibody. The parameters of the method were evaluated and optimized. The established MPs-CLEIA method had a linear range from 0.31 to 100ng/ml with a detection limit of 0.24ng/ml. The assays showed low reactivities and less than 5% of intraassay and interassay coefficients of variation (CVs), and the average recoveries were between 92 and 97%. Furthermore, the developed method was applied in real samples analysis successfully, and the correlation coefficient with the commercially available OVA kit was 0.9976. Moreover, it was more rapid and sensitive compared with the other methods for testing OVA. Copyright © 2014 Elsevier Inc. All rights reserved.

  9. Nonvolatile memory design magnetic, resistive, and phase change

    CERN Document Server

    Li, Hai

    2011-01-01

    The manufacture of flash memory, which is the dominant nonvolatile memory technology, is facing severe technical barriers. So much so, that some emerging technologies have been proposed as alternatives to flash memory in the nano-regime. Nonvolatile Memory Design: Magnetic, Resistive, and Phase Changing introduces three promising candidates: phase-change memory, magnetic random access memory, and resistive random access memory. The text illustrates the fundamental storage mechanism of these technologies and examines their differences from flash memory techniques. Based on the latest advances,

  10. Ethnobiology 5: Interdisciplinarity in an Era of Rapid Environmental Change

    Directory of Open Access Journals (Sweden)

    Steve Wolverton

    2013-01-01

    Full Text Available Ethnobiology 5 stems from Eugene Hunn’s four phases of the history of ethnobiology and focuses on the relevance of ethnobiological research in the context of environmental and cultural change.  It refers to a contemporary phase of the field’s historical development.  In this paper, I argue that ethnobiology is preadapted to be a scholarly umbrella for a number of disciplines that concern human-environment interactions, suggesting that one goal of Ethnobiology 5 is to bridge traditional academic boundaries in order to broaden the community of ethnobiologists. Another goal of Ethnobiology 5 is to capitalize on and communicate the relevance of ethnobiological scholarship for solving problems related to contemporary environmental and cultural crises.  Indeed, ethnobiology is not a subfield of any traditional discipline and by the nature of its name bridges humanities, social science, and science.  Ethnobiology has always been interdisciplinary in terms of its subject matter, yet its community of scholars is relatively small compared to mission-driven disciplines, such as conservation biology.  Venues for publication and presentation of ethnobiological research, as well as how ethnobiologists portray their research, are critical to growing ethnobiology.

  11. Coral Reefs Under Rapid Climate Change and Ocean Acidification

    Science.gov (United States)

    Hoegh-Guldberg, O.; Mumby, P. J.; Hooten, A. J.; Steneck, R. S.; Greenfield, P.; Gomez, E.; Harvell, C. D.; Sale, P. F.; Edwards, A. J.; Caldeira, K.; Knowlton, N.; Eakin, C. M.; Iglesias-Prieto, R.; Muthiga, N.; Bradbury, R. H.; Dubi, A.; Hatziolos, M. E.

    2007-12-01

    Atmospheric carbon dioxide concentration is expected to exceed 500 parts per million and global temperatures to rise by at least 2°C by 2050 to 2100, values that significantly exceed those of at least the past 420,000 years during which most extant marine organisms evolved. Under conditions expected in the 21st century, global warming and ocean acidification will compromise carbonate accretion, with corals becoming increasingly rare on reef systems. The result will be less diverse reef communities and carbonate reef structures that fail to be maintained. Climate change also exacerbates local stresses from declining water quality and overexploitation of key species, driving reefs increasingly toward the tipping point for functional collapse. This review presents future scenarios for coral reefs that predict increasingly serious consequences for reef-associated fisheries, tourism, coastal protection, and people. As the International Year of the Reef 2008 begins, scaled-up management intervention and decisive action on global emissions are required if the loss of coral-dominated ecosystems is to be avoided.

  12. Dynamics of the solar magnetic field. V. Velocities associated with changing magnetic fields

    International Nuclear Information System (INIS)

    Levine, R.H.; Nakagawa, Y.

    1975-01-01

    Methods of determining horizontal velocities from the magnetic induction equation on the basis of a time series of magnetogram observations are discussed. For the flare of 1972 August 7, it is shown that a previously developed method of predicting positions of likely flare activity provides reasonable agreement with observations. Limitations to this type of solution of the magnetic induction equation are pointed out, and unambiguous solutions, corresponding to phenomenological determinations of velocity patterns under various physical circumstances, are presented for simple magnetic configurations. Implications for the analysis of changes in a series of magnetogram observations are discussed

  13. Phase composition, structure and magnetic behaviour of low neodymium rapid-quenched Nd-Fe-B alloys

    Czech Academy of Sciences Publication Activity Database

    Ćosović, V.; Žák, Tomáš; Talijan, N.; Grujić, A.; Stajić-Trošić, J.

    2008-01-01

    Roč. 456, 1-2 (2008), s. 251-256 ISSN 0925-8388 R&D Projects: GA MŠk 1M0512 Institutional research plan: CEZ:AV0Z20410507 Keywords : multiphase Nd(Pr)-Fe-B alloys * rapid solidification * magnetic measurements * Mossbauer spectroscopy * X-ray diffraction * Nanocrystalline composite Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.510, year: 2008

  14. Health impacts of rapid economic changes in Thailand.

    Science.gov (United States)

    Tangcharoensathien, V; Harnvoravongchai, P; Pitayarangsarit, S; Kasemsup, V

    2000-09-01

    The economic crisis in Thailand in July 1997 had major social implications for unemployment, under employment, household income contraction, changing expenditure patterns, and child abandonment. The crisis increased poverty incidence by 1 million, of whom 54% were the ultra-poor. This paper explores and explains the short-term health impact of the crisis, using existing data and some special surveys and interviews for 2 years during 1998-99. The health impacts of the crisis are mixed, some being negative and some being positive. Household health expenditure reduced by 24% in real terms; among the poorer households, institutional care was replaced by self-medication. The pre-crisis rising trend in expenditure on alcohol and tobacco consumption was reversed. Immunization spending and coverage were sustained at a very high level after the crisis, but reports of increases in diphtheria and pertussis indicate declining programme quality. An increase in malaria, despite budget increases, had many causes but was mainly due to reduced programme effectiveness. STD incidence continued the pre-crisis downward trend. Rates of HIV risky sexual behaviour were higher among conscripts than other male workers, but in both groups there was lower condom use with casual partners. HIV serosurveillance showed a continuation of the pre-crisis downward trend among commercial sex workers (CSW, both brothel and non-brothel based), pregnant women and donated blood; this trend was slightly reversed among male STD patients and more among intravenous drug users. Condom coverage among brothel based CSW continued to increase to 97.5%, despite a 72% budget cut in free condom distribution. Poverty and lack of insurance coverage are two major determinants of absence of or inadequate antenatal care, and low birthweight. The Low Income Scheme could not adequately cover the poor but the voluntary Health Card Scheme played a health safety net role for maternal and child health. Low birthweight and

  15. Hard magnetic properties of rapidly annealed NdFeB thin films on Nb and V buffer layers

    International Nuclear Information System (INIS)

    Jiang, H.; Evans, J.; O'Shea, M.J.; Du Jianhua

    2001-01-01

    NdFeB thin films of the form A (20 nm)/NdFeB(d nm)/A(20 nm), where d ranges from 54 to 540 nm and the buffer layer A is Nb or V were prepared on a Si(1 0 0) substrate by magnetron sputtering. The hard Nd 2 Fe 14 B phase is formed by a 30 s rapid anneal or a 20 min anneal. Average crystallite size ranged from 20 to 35 nm with the rapidly annealed samples having the smaller crystallite size. These samples also exhibited a larger coercivity and energy product than those treated by a 20 min vacuum anneal. A maximum coercivity of 26.3 kOe at room temperature was obtained for a Nb/NdFeB (180 nm)/Nb film after a rapid anneal at 725 deg. C. Initial magnetization curves indicate magnetization rotation rather than nucleation of reverse domains is important in the magnetization process. A Brown's equation analysis of the coercivity as a function of temperature allowed us to compare the rapidly annealed and 20 min annealed samples. This analysis suggests that rapid annealing gives higher quality crystalline grains than the 20 min annealed sample leading to the observed large coercivity in the rapidly annealed samples

  16. RAPID PENUMBRA AND LORENTZ FORCE CHANGES IN AN X1.0 SOLAR FLARE

    International Nuclear Information System (INIS)

    Xu, Zhe; Jiang, Yunchun; Yang, Jiayang; Yang, Bo; Bi, Yi

    2016-01-01

    We present observations of the violent changes in photospheric magnetic structures associated with an X1.1 flare, which occurred in a compact δ-configuration region in the following part of AR 11890 on 2013 November 8. In both central and peripheral penumbra regions of the small δ sunspot, these changes took place abruptly and permanently in the reverse direction during the flare: the inner/outer penumbra darkened/disappeared, where the magnetic fields became more horizontal/vertical. Particularly, the Lorentz force (LF) changes in the central/peripheral region had a downward/upward and inward direction, meaning that the local pressure from the upper atmosphere was enhanced/released. It indicates that the LF changes might be responsible for the penumbra changes. These observations can be well explained as the photospheric response to the coronal field reconstruction within the framework of the magnetic implosion theory and the back reaction model of flares

  17. Rapid microwave-assisted regeneration of magnetic carbon nanotubes loaded with p-nitrophenol

    International Nuclear Information System (INIS)

    Cui, Chunyue; Zheng, Qingzhu; Han, Yanhe; Xin, Yanjun

    2015-01-01

    Highlights: • Magnetic CNTs material was successfully synthesized. • Magnetic CNTs have high fast adsorption rate and adsorption capacity. • Magnetic CNTs can be easily separated from the water by external magnetic field. • Magnetic CNTs can be recycled by MW irradiation regeneration. - Abstract: A novel magnetic carbon nanotubes (CNTs) adsorbent with good sorption, magnetic separability, and microwave (MW) regeneration properties was prepared successfully using thermal decomposition. The magnetic CNTs were characterized using transmission electron microscopy, energy dispersive X-ray, nitrogen adsorption (Brunauer–Emmett–Teller surface area), and X-ray diffraction and their magnetic properties were measured using a vibrating sample magnetometer. Magnetic nanoparticles (≈10 nm diameter) were dispersed uniformly on the CNTs with a magnetic CNTs surface area of 146.7 m 2 g −1 and a saturation magnetization of 21.11 emu g −1 . When the magnetic CNTs were used in the sorption of p-nitrophenol, the equilibrium time was 20 min and the sorption isotherms fit the Freundlich isotherm well. The spent magnetic CNTs could be separated magnetically and be regenerated by MW irradiation. After six adsorption and MW regeneration cycles (at 850 W for 180 s), the adsorption capacity of the magnetic CNTs was higher than that of the virgin magnetic CNTs with a low carbon loss

  18. Assessment of Alphamagnetic Spectrometer (AMS) Upper Experiment Structural Configuration Shielding Effectiveness Associated with Change from Cryo-Cooled Magnet to Permanent Magnet

    Science.gov (United States)

    Scully, Robert

    2012-01-01

    In the spring of 2010, the Alpha Magnetic Spectrometer 2 (AMS-02) underwent a series of system level electromagnetic interference control measurements, followed by thermal vacuum testing. Shortly after completion of the thermal vacuum testing, the project decided to remove the cryogenically cooled superconducting magnet, and replace it with the original permanent magnet design employed in the earlier AMS- 01 assembly. Doing so necessitated several structural changes, as well as removal or modification of numerous electronic and thermal control devices and systems. At this stage, the project was rapidly approaching key milestone dates for hardware completion and delivery for launch, and had little time for additional testing or assessment of any impact to the electromagnetic signature of the AMS-02. Therefore, an analytical assessment of the radiated emissions behavioural changes associated with the system changes was requested.

  19. Rapid non-contrast magnetic resonance imaging for post appendectomy intra-abdominal abscess in children

    International Nuclear Information System (INIS)

    Lee, Megan H.; Eutsler, Eric P.; Khanna, Geetika; Sheybani, Elizabeth F.

    2017-01-01

    Acute appendicitis, especially if perforated at presentation, is often complicated by postoperative abscess formation. The detection of a postoperative abscess relies primarily on imaging. This has traditionally been done with contrast-enhanced computed tomography. Non-contrast magnetic resonance imaging (MRI) has the potential to accurately detect intra-abdominal abscesses, especially with the use of diffusion-weighted imaging (DWI). To evaluate our single-center experience with a rapid non-contrast MRI protocol evaluating post-appendectomy abscesses in children with persistent postsurgical symptoms. In this retrospective, institutional review board-approved study, all patients underwent a clinically indicated non-contrast 1.5- or 3-Tesla abdomen/pelvis MRI consisting of single-shot fast spin echo, inversion recovery and DWI sequences. All MRI studies were reviewed by two blinded pediatric radiologists to identify the presence of a drainable fluid collection. Each fluid collection was further characterized as accessible or not accessible for percutaneous or transrectal drainage. Imaging findings were compared to clinical outcome. Seven of the 15 patients had a clinically significant fluid collection, and 5 of these patients were treated with percutaneous drain placement or exploratory laparotomy. The other patients had a phlegmon or a clinically insignificant fluid collection and were discharged home within 48 h. Rapid non-contrast MRI utilizing fluid-sensitive and DWI sequences can be used to identify drainable fluid collections in post-appendectomy patients. This protocol can be used to triage patients between conservative management vs. abscess drainage without oral/intravenous contrast or exposure to ionizing radiation. (orig.)

  20. Rapid non-contrast magnetic resonance imaging for post appendectomy intra-abdominal abscess in children

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Megan H. [Washington University School of Medicine in St. Louis, Mallinckrodt Institute of Radiology, St. Louis, MO (United States); Eutsler, Eric P.; Khanna, Geetika [Washington University School of Medicine in St. Louis, Pediatric Radiology, Mallinckrodt Institute of Radiology, St. Louis, MO (United States); Sheybani, Elizabeth F. [Mercy Hospital St. Louis, Department of Radiology, St. Louis, MO (United States)

    2017-07-15

    Acute appendicitis, especially if perforated at presentation, is often complicated by postoperative abscess formation. The detection of a postoperative abscess relies primarily on imaging. This has traditionally been done with contrast-enhanced computed tomography. Non-contrast magnetic resonance imaging (MRI) has the potential to accurately detect intra-abdominal abscesses, especially with the use of diffusion-weighted imaging (DWI). To evaluate our single-center experience with a rapid non-contrast MRI protocol evaluating post-appendectomy abscesses in children with persistent postsurgical symptoms. In this retrospective, institutional review board-approved study, all patients underwent a clinically indicated non-contrast 1.5- or 3-Tesla abdomen/pelvis MRI consisting of single-shot fast spin echo, inversion recovery and DWI sequences. All MRI studies were reviewed by two blinded pediatric radiologists to identify the presence of a drainable fluid collection. Each fluid collection was further characterized as accessible or not accessible for percutaneous or transrectal drainage. Imaging findings were compared to clinical outcome. Seven of the 15 patients had a clinically significant fluid collection, and 5 of these patients were treated with percutaneous drain placement or exploratory laparotomy. The other patients had a phlegmon or a clinically insignificant fluid collection and were discharged home within 48 h. Rapid non-contrast MRI utilizing fluid-sensitive and DWI sequences can be used to identify drainable fluid collections in post-appendectomy patients. This protocol can be used to triage patients between conservative management vs. abscess drainage without oral/intravenous contrast or exposure to ionizing radiation. (orig.)

  1. Diagnostic Performance of a Rapid Magnetic Resonance Imaging Method of Measuring Hepatic Steatosis

    Science.gov (United States)

    House, Michael J.; Gan, Eng K.; Adams, Leon A.; Ayonrinde, Oyekoya T.; Bangma, Sander J.; Bhathal, Prithi S.; Olynyk, John K.; St. Pierre, Tim G.

    2013-01-01

    Objectives Hepatic steatosis is associated with an increased risk of developing serious liver disease and other clinical sequelae of the metabolic syndrome. However, visual estimates of steatosis from histological sections of biopsy samples are subjective and reliant on an invasive procedure with associated risks. The aim of this study was to test the ability of a rapid, routinely available, magnetic resonance imaging (MRI) method to diagnose clinically relevant grades of hepatic steatosis in a cohort of patients with diverse liver diseases. Materials and Methods Fifty-nine patients with a range of liver diseases underwent liver biopsy and MRI. Hepatic steatosis was quantified firstly using an opposed-phase, in-phase gradient echo, single breath-hold MRI methodology and secondly, using liver biopsy with visual estimation by a histopathologist and by computer-assisted morphometric image analysis. The area under the receiver operating characteristic (ROC) curve was used to assess the diagnostic performance of the MRI method against the biopsy observations. Results The MRI approach had high sensitivity and specificity at all hepatic steatosis thresholds. Areas under ROC curves were 0.962, 0.993, and 0.972 at thresholds of 5%, 33%, and 66% liver fat, respectively. MRI measurements were strongly associated with visual (r2 = 0.83) and computer-assisted morphometric (r2 = 0.84) estimates of hepatic steatosis from histological specimens. Conclusions This MRI approach, using a conventional, rapid, gradient echo method, has high sensitivity and specificity for diagnosing liver fat at all grades of steatosis in a cohort with a range of liver diseases. PMID:23555650

  2. Rapid determination of iron oxide content in magnetically modified particulate materials

    Czech Academy of Sciences Publication Activity Database

    Šafařík, Ivo; Nýdlová, L.; Pospíšková, K.; Baldíková, E.; Maděrová, Z.; Šafaříková, Miroslava

    2016-01-01

    Roč. 26, June (2016), s. 114-117 ISSN 1674-2001 Institutional support: RVO:60077344 Keywords : magnetic iron oxide s * magnetic permeability meter * magnetically modified materials Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.621, year: 2016

  3. Optimizing the magnetization-prepared rapid gradient-echo (MP-RAGE sequence.

    Directory of Open Access Journals (Sweden)

    Jinghua Wang

    Full Text Available The three-dimension (3D magnetization-prepared rapid gradient-echo (MP-RAGE sequence is one of the most popular sequences for structural brain imaging in clinical and research settings. The sequence captures high tissue contrast and provides high spatial resolution with whole brain coverage in a short scan time. In this paper, we first computed the optimal k-space sampling by optimizing the contrast of simulated images acquired with the MP-RAGE sequence at 3.0 Tesla using computer simulations. Because the software of our scanner has only limited settings for k-space sampling, we then determined the optimal k-space sampling for settings that can be realized on our scanner. Subsequently we optimized several major imaging parameters to maximize normal brain tissue contrasts under the optimal k-space sampling. The optimal parameters are flip angle of 12°, effective inversion time within 900 to 1100 ms, and delay time of 0 ms. In vivo experiments showed that the quality of images acquired with our optimal protocol was significantly higher than that of images obtained using recommended protocols in prior publications. The optimization of k-spacing sampling and imaging parameters significantly improved the quality and detection sensitivity of brain images acquired with MP-RAGE.

  4. A multiple-proxy approach to understanding rapid Holocene climate change in Southeast Greenland

    Science.gov (United States)

    Davin, S. H.; Bradley, R. S.; Balascio, N. L.; de Wet, G.

    2012-12-01

    The susceptibility of the Arctic to climate change has made it an excellent workshop for paleoclimatological research. Although there have been previous studies concerning climate variability carried out in the Arctic, there remains a critical dearth of knowledge due the limited number of high-resolution Holocene climate-proxy records available from this region. This gap skews our understanding of observed and predicted climate change, and fuels uncertainty both in the realms of science and policy. This study takes a comprehensive approach to tracking Holocene climate variability in the vicinity of Tasiilaq, Southeast Greenland using a ~5.6 m sediment core from Lower Sermilik Lake. An age-depth model for the core has been established using 8 radiocarbon dates, the oldest of which was taken at 4 m down core and has been been dated to approximately 6.2 kyr BP. The bottom meter of the core below the final radiocarbon date contains a transition from cobbles and coarse sand to organic-rich laminations, indicating the termination of direct glacial influence and therefore likely marking the end of the last glacial period in this region. The remainder of the core is similarly organic-rich, with light-to-dark brown laminations ranging from 0.5 -1 cm in thickness and riddled with turbidites. Using this core in tandem with findings from an on-site assessment of the geomorphic history of the locale we attempt to assess and infer the rapid climatic shifts associated with the Holocene on a sub-centennial scale. Such changes include the termination of the last glacial period, the Mid-Holocene Climatic Optimum, the Neoglacial Period, the Medieval Climatic Optimum, and the Little Ice Age. A multiple proxy approach including magnetic susceptibility, bulk organic geochemistry, elemental profiles acquired by XRF scanning, grain-size, and spectral data will be used to characterize the sediment and infer paleoclimate conditions. Additionally, percent biogenic silica by weight has been

  5. Long-term culture change related to rapid response system implementation.

    Science.gov (United States)

    Stevens, Jennifer; Johansson, Anna; Lennes, Inga; Hsu, Douglas; Tess, Anjala; Howell, Michael

    2014-12-01

    Increasing attention to patient safety in training hospitals may come at the expense of trainee autonomy and professional growth. This study sought to examine changes in medical trainees' self-reported behaviour after the institution-wide implementation of a rapid response system. We conducted a two-point cross-sectional survey of medical trainees in 2006, during the implementation of a rapid response system, and in 2010, in a single academic medical centre. A novel instrument was used to measure trainee likelihood of calling for supervisory assistance, perception of autonomy, and comfort in managing decompensating patients. Non-parametric tests to assess for change were used and year of training was evaluated as an effect modifier. Response rates were 38% in 2006 and 70% in 2010. After 5 years of the full implementation of the rapid response system, residents were significantly more likely to report calling their attending physicians for assistance (rising from 40% to 65% of relevant situations; p autonomy at 5 years after the implementation of the rapid response system. These changes were mirrored in the actual use of the rapid response system, which increased by 41% during the 5-year period after adjustment for patient volume (p < 0.0001). A primary team-focused implementation of a rapid response system was associated with durable changes in resident physicians' reported behaviour, including increased comfort with involving more experienced physicians and managing unstable patients. © 2014 John Wiley & Sons Ltd.

  6. Rapid changes in the range limits of Scots pine 4000 years ago

    International Nuclear Information System (INIS)

    Gear, A.J.; Huntley, B.

    1991-01-01

    Paleoecological data provide estimates of response rates to past climate changes. Fossil Pinus sylvestris stumps in far northern Scotland demonstrate former presence of pine trees where conventional pollen evidence of pine forests is lacking. Radiocarbon, dendrochronological, and fine temporal-resolution palynological data show that pine forest were present for about four centuries some 4,000 years ago; the forests expanded and then retreated rapidly some 70 to 80 kilometers. Despite the rapidity of this response to climate change, it occurred at rates slower by an order of magnitude than those necessary to maintain equilibrium with forecast climate changes attributed to the greenhouse effect

  7. Understanding rapid theoretical change in particle physics: a month-by-month co-citation analysis

    International Nuclear Information System (INIS)

    Sullivan, D.; Koester, D.; White, D.H.; Kern, R.

    1979-01-01

    While co-citation analysis has proved a powerful tool in the study of changes in intellectual foci in science, no one has ever used the technique to study very rapid changes in the theoretical structure of a scientific field. This paper presents month-by-month co-citation analyses of key phases in the weak-electromagnetic unification research program within particle physics, and shows that these analyses capture and illuminate very rapid intellectual changes. These data provide yet another illustration of the utility of co-citation analysis for understanding the history of science. 8 figures

  8. Rapid climate change did not cause population collapse at the end of the European Bronze Age.

    Science.gov (United States)

    Armit, Ian; Swindles, Graeme T; Becker, Katharina; Plunkett, Gill; Blaauw, Maarten

    2014-12-02

    The impact of rapid climate change on contemporary human populations is of global concern. To contextualize our understanding of human responses to rapid climate change it is necessary to examine the archeological record during past climate transitions. One episode of abrupt climate change has been correlated with societal collapse at the end of the northwestern European Bronze Age. We apply new methods to interrogate archeological and paleoclimate data for this transition in Ireland at a higher level of precision than has previously been possible. We analyze archeological (14)C dates to demonstrate dramatic population collapse and present high-precision proxy climate data, analyzed through Bayesian methods, to provide evidence for a rapid climatic transition at ca. 750 calibrated years B.C. Our results demonstrate that this climatic downturn did not initiate population collapse and highlight the nondeterministic nature of human responses to past climate change.

  9. Curioser and Curioser: New Concepts in the Rapidly Changing Landscape of Educational Administration.

    Science.gov (United States)

    Fowler, Frances C.

    1999-01-01

    The new "Handbook" assumes that society is changing rapidly and educational administration must change with it. This article critiques chapters on four concepts: ideology, the new consumerism, social capital, and the new institutionalism. Consumerism is pure 19th-century liberalism/individualism; social capital theory and…

  10. Extremely rapid directional change during Matuyama-Brunhes geomagnetic polarity reversal

    Science.gov (United States)

    Sagnotti, Leonardo; Scardia, Giancarlo; Giaccio, Biagio; Liddicoat, Joseph C.; Nomade, Sebastien; Renne, Paul R.; Sprain, Courtney J.

    2014-11-01

    We report a palaeomagnetic investigation of the last full geomagnetic field reversal, the Matuyama-Brunhes (M-B) transition, as preserved in a continuous sequence of exposed lacustrine sediments in the Apennines of Central Italy. The palaeomagnetic record provides the most direct evidence for the tempo of transitional field behaviour yet obtained for the M-B transition. 40Ar/39Ar dating of tephra layers bracketing the M-B transition provides high-accuracy age constraints and indicates a mean sediment accumulation rate of about 0.2 mm yr-1 during the transition. Two relative palaeointensity (RPI) minima are present in the M-B transition. During the terminus of the upper RPI minimum, a directional change of about 180 ° occurred at an extremely fast rate, estimated to be less than 2 ° per year, with no intermediate virtual geomagnetic poles (VGPs) documented during the transit from the southern to northern hemisphere. Thus, the entry into the Brunhes Normal Chron as represented by the palaeomagnetic directions and VGPs developed in a time interval comparable to the duration of an average human life, which is an order of magnitude more rapid than suggested by current models. The reported investigation therefore provides high-resolution integrated palaeomagnetic and radioisotopic data that document the fine details of the anatomy and tempo of the M-B transition in Central Italy that in turn are crucial for a better understanding of Earth's magnetic field, and for the development of more sophisticated models that are able to describe its global structure and behaviour.

  11. Combining magnetic nanoparticle with biotinylated nanobodies for rapid and sensitive detection of influenza H3N2

    Science.gov (United States)

    Zhu, Min; Hu, Yonghong; Li, Guirong; Ou, Weijun; Mao, Panyong; Xin, Shaojie; Wan, Yakun

    2014-09-01

    Our objective is to develop a rapid and sensitive assay based on magnetic beads to detect the concentration of influenza H3N2. The possibility of using variable domain heavy-chain antibodies (nanobody) as diagnostic tools for influenza H3N2 was investigated. A healthy camel was immunized with inactivated influenza H3N2. A nanobody library of 8 × 108 clones was constructed and phage displayed. After three successive biopanning steps, H3N2-specific nanobodies were successfully isolated, expressed in Escherichia coli, and purified. Sequence analysis of the nanobodies revealed that we possessed four classes of nanobodies against H3N2. Two nanobodies were further used to prepare our rapid diagnostic kit. Biotinylated nanobody was effectively immobilized onto the surface of streptavidin magnetic beads. The modified magnetic beads with nanobody capture specifically influenza H3N2 and can still be recognized by nanobodies conjugated to horseradish peroxidase (HRP) conjugates. Under optimized conditions, the present immunoassay exhibited a relatively high sensitive detection with a limit of 50 ng/mL. In conclusion, by combining magnetic beads with specific nanobodies, this assay provides a promising influenza detection assay to develop a potential rapid, sensitive, and low-cost diagnostic tool to screen for influenza infections.

  12. Rapid and accurate biofuel moisture content gauging using magnetic resonance measurement technology

    Energy Technology Data Exchange (ETDEWEB)

    Jaervinen, T.

    2013-04-15

    Biomass is extensively utilised in energy production and as a raw material, such as for the production of liquid biofuels. All those processes will benefit if the moisture content of bio material is known in advance as accurately as possible under transient circumstances. Biofuel trade is increasingly based on the calorific value of fuels. In the first step, this also increases the need for rapid and accurate moisture content determination. During the last few years, large biofuel standardisation has been implemented, emphasising biofuel quality control at all stages of the utilisation chain. In principle, the moisture instrumental measurement can be utilised by many technologies and procedures. Typical techniques are infrared, radiofrequency, microwave, radiometric, electrical conductivity, capacitance, and impedance. Nuclear magnetic resonance (MR) and thermal neutron absorption are also applied. The MR measurement principle has been known and utilised already since the early 1950s. It has become the basic instrumental analysis tool in chemistry. It is also well-known as a very accurate method for analysing most compounds, especially substances containing hydrogen. The utilisation of MR metering is expanded extensively to medical diagnostics as a form of magnetic resonance imaging (MRI). Because of the precision of the MR principle, there have for a long time been efforts to apply it in new and different areas, and to make more user-friendly, smaller, and even portable devices. Such a device was designed by Vaisala a few years ago. VTT has utilised Vaisala's MR prototype for approximately one year for moisture content measurement of different biofuels. The first step in the use of an MR device for moisture determination was the definition of its measurement accuracy compared to the standard method (EN 14774). Those tests proved that the absolute precision seems to be comparable to the standard moisture content measurement method. It was also found out that

  13. Development of rapid methods for relaxation time mapping and motion estimation using magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Gilani, Syed Irtiza Ali

    2008-09-15

    Recent technological developments in the field of magnetic resonance imaging have resulted in advanced techniques that can reduce the total time to acquire images. For applications such as relaxation time mapping, which enables improved visualisation of in vivo structures, rapid imaging techniques are highly desirable. TAPIR is a Look- Locker-based sequence for high-resolution, multislice T{sub 1} relaxation time mapping. Despite the high accuracy and precision of TAPIR, an improvement in the k-space sampling trajectory is desired to acquire data in clinically acceptable times. In this thesis, a new trajectory, termed line-sharing, is introduced for TAPIR that can potentially reduce the acquisition time by 40 %. Additionally, the line-sharing method was compared with the GRAPPA parallel imaging method. These methods were employed to reconstruct time-point images from the data acquired on a 4T high-field MR research scanner. Multislice, multipoint in vivo results obtained using these methods are presented. Despite improvement in acquisition speed, through line-sharing, for example, motion remains a problem and artefact-free data cannot always be obtained. Therefore, in this thesis, a rapid technique is introduced to estimate in-plane motion. The presented technique is based on calculating the in-plane motion parameters, i.e., translation and rotation, by registering the low-resolution MR images. The rotation estimation method is based on the pseudo-polar FFT, where the Fourier domain is composed of frequencies that reside in an oversampled set of non-angularly, equispaced points. The essence of the method is that unlike other Fourier-based registration schemes, the employed approach does not require any interpolation to calculate the pseudo-polar FFT grid coordinates. Translation parameters are estimated by the phase correlation method. However, instead of two-dimensional analysis of the phase correlation matrix, a low complexity subspace identification of the phase

  14. Development of rapid methods for relaxation time mapping and motion estimation using magnetic resonance imaging

    International Nuclear Information System (INIS)

    Gilani, Syed Irtiza Ali

    2008-09-01

    Recent technological developments in the field of magnetic resonance imaging have resulted in advanced techniques that can reduce the total time to acquire images. For applications such as relaxation time mapping, which enables improved visualisation of in vivo structures, rapid imaging techniques are highly desirable. TAPIR is a Look- Locker-based sequence for high-resolution, multislice T 1 relaxation time mapping. Despite the high accuracy and precision of TAPIR, an improvement in the k-space sampling trajectory is desired to acquire data in clinically acceptable times. In this thesis, a new trajectory, termed line-sharing, is introduced for TAPIR that can potentially reduce the acquisition time by 40 %. Additionally, the line-sharing method was compared with the GRAPPA parallel imaging method. These methods were employed to reconstruct time-point images from the data acquired on a 4T high-field MR research scanner. Multislice, multipoint in vivo results obtained using these methods are presented. Despite improvement in acquisition speed, through line-sharing, for example, motion remains a problem and artefact-free data cannot always be obtained. Therefore, in this thesis, a rapid technique is introduced to estimate in-plane motion. The presented technique is based on calculating the in-plane motion parameters, i.e., translation and rotation, by registering the low-resolution MR images. The rotation estimation method is based on the pseudo-polar FFT, where the Fourier domain is composed of frequencies that reside in an oversampled set of non-angularly, equispaced points. The essence of the method is that unlike other Fourier-based registration schemes, the employed approach does not require any interpolation to calculate the pseudo-polar FFT grid coordinates. Translation parameters are estimated by the phase correlation method. However, instead of two-dimensional analysis of the phase correlation matrix, a low complexity subspace identification of the phase

  15. Basic study for plastic deformation of rapidly quenched Nd-Fe-Co-Ga-B magnets at elevated temperature

    International Nuclear Information System (INIS)

    Akayama, M.; Tanigawa, S.; Tokunaga, M.

    1990-01-01

    In order to optimize hot working conditions of rapidly quenched Nd-Fe-C-Ga-B magnets, the behavior of plastic deformation at elevated temperatures has been studied. Compressive and tensile tests were performed with various hot working parameters. Computer simulation of the die upsetting process was performed by rigid plastic FEM calculation. It was found that, to suppress the occurrence of peripheral cracks and improve magnetic properties, low strain rates are necessary. Computer calculation of the distribution of stress can explain the mechanism of peripheral crack initiation in the die upsetting process

  16. Monitoring changes in seismic velocity related to an ongoing rapid inflation event at Okmok volcano, Alaska

    Science.gov (United States)

    Bennington, Ninfa; Haney, Matt; De Angelis, Silvio; Thurber, Clifford; Freymueller, Jeff

    2015-01-01

    Okmok is one of the most active volcanoes in the Aleutian Arc. In an effort to improve our ability to detect precursory activity leading to eruption at Okmok, we monitor a recent, and possibly ongoing, GPS-inferred rapid inflation event at the volcano using ambient noise interferometry (ANI). Applying this method, we identify changes in seismic velocity outside of Okmok’s caldera, which are related to the hydrologic cycle. Within the caldera, we observe decreases in seismic velocity that are associated with the GPS-inferred rapid inflation event. We also determine temporal changes in waveform decorrelation and show a continual increase in decorrelation rate over the time associated with the rapid inflation event. Themagnitude of relative velocity decreases and decorrelation rate increases are comparable to previous studies at Piton de la Fournaise that associate such changes with increased production of volatiles and/ormagmatic intrusion within the magma reservoir and associated opening of fractures and/or fissures. Notably, the largest decrease in relative velocity occurs along the intrastation path passing nearest to the center of the caldera. This observation, along with equal amplitude relative velocity decreases revealed via analysis of intracaldera autocorrelations, suggests that the inflation sourcemay be located approximately within the center of the caldera and represent recharge of shallow magma storage in this location. Importantly, there is a relative absence of seismicity associated with this and previous rapid inflation events at Okmok. Thus, these ANI results are the first seismic evidence of such rapid inflation at the volcano.

  17. Effect of component substitution on the magnetic properties of Zr2Co11 phase and rapidly quenched Zr2Co11 - based alloys

    International Nuclear Information System (INIS)

    Gabaj, A.M.; Shchegoleva, N.N.; Gaviko, V.S.; Ivanova, G.V.

    2003-01-01

    Magnetic properties of homogenized ingots and rapidly quenched ribbons of (Zr 1-x M x ) 16.4 Co 83.6 with M=Ti, Nb, Y, Gd and Zr 16.4 (Co 1-y M* y ) 83.6 with M*= Mn, Fe, Ni, Cu, Al, Ga, Si are studied. The phase composition of the alloys is determined with the help of thermomagnetic analysis and, in specific cases, with the use of X-ray diffraction analysis and electron microscopical data. It is ascertained that a part of zirconium in a phase Zr 2 Co 11 can be replaced by titanium and niobium. The solubility of rare earth elements is noted to be not revealed. Cobalt is partially replaced by Al, Cu, Ga, Si, Ni and Fe in a 2:11 phase, and Mn stabilizes the structure of a Laves phase with unexpectedly strong ferromagnetic properties. For magnetic hardness of the rapidly quenched alloys the introduction of Ti is appeared to be most beneficial. This element enhances noticeably the coercive force and hysteresis loop rectangularity and, as it takes place, it does not change practically magnetic properties of a 2:11 phase but suppresses the formation of dendrites on its crystallization. A small increase of the coercive force is also observed on addition of Cu and Al [ru

  18. Rapid ecosystem change challenges the adaptive capacity of Local Environmental Knowledge.

    Science.gov (United States)

    Fernández-Llamazares, Álvaro; Díaz-Reviriego, Isabel; Luz, Ana C; Cabeza, Mar; Pyhälä, Aili; Reyes-García, Victoria

    2015-03-01

    The use of Local Environmental Knowledge has been considered as an important strategy for adaptive management in the face of Global Environmental Change. However, the unprecedented rates at which global change occurs may pose a challenge to the adaptive capacity of local knowledge systems. In this paper, we use the concept of the shifting baseline syndrome to examine the limits in the adaptive capacity of the local knowledge of an indigenous society facing rapid ecosystem change. We conducted semi-structured interviews regarding perceptions of change in wildlife populations and in intergenerational transmission of knowledge amongst the Tsimane', a group of hunter-gatherers of Bolivian Amazonia ( n = 300 adults in 13 villages). We found that the natural baseline against which the Tsimane' measure ecosystem changes might be shifting with every generation as a result of (a) age-related differences in the perception of change and (b) a decrease in the intergenerational sharing of environmental knowledge. Such findings suggest that local knowledge systems might not change at a rate quick enough to adapt to conditions of rapid ecosystem change, hence potentially compromising the adaptive success of the entire social-ecological system. With the current pace of Global Environmental Change, widening the gap between the temporal rates of on-going ecosystem change and the timescale needed for local knowledge systems to adjust to change, efforts to tackle the shifting baseline syndrome are urgent and critical for those who aim to use Local Environmental Knowledge as a tool for adaptive management.

  19. Microstructure and magnetic properties of rapidly solidified nanocrystalline Fe81Zr7B12 alloy

    International Nuclear Information System (INIS)

    Xiong, X.Y.; Muddle, B.C.; Finlayson, T.R.

    2000-01-01

    Full text: Nanocrystalline Fe-Zr-B alloys have aroused extensive research interest due to their high saturation magnetization. There have been several studies [Suzuki et al., 1994; Kim et al., 1994] of the effect of boron on the formation of nanocrystalline structure and magnetic properties, showing that the addition of boron to Fe-Zr alloys improves the glass-forming ability and refines the primary bcc α-Fe grains during crystallization. However, when the boron content is increased to 8 at.%, the magnetic permeability is observed to decrease. There has been no detailed work to date concerning the microstructural evolution and magnetic properties in those alloys with higher boron content

  20. Engaging Chicago residents in climate change action: Results from Rapid Ethnographic Inquiry

    Science.gov (United States)

    Lynne M. Westphal; Jennifer. Hirsch

    2010-01-01

    Addressing climate change requires action at all levels of society, from neighborhood to international levels. Using Rapid Ethnography rooted in Asset Based Community Development theory, we investigated climate-friendly attitudes and behaviors in two Chicago neighborhoods in order to assist the City with implementation of its Climate Action Plan. Our research suggests...

  1. Computed tomographic demonstration of rapid changes in fatty infiltration of the liver

    International Nuclear Information System (INIS)

    Bashist, B.; Hecht, H.L.; Harely, W.D.

    1982-01-01

    Two alcoholic patients in whom computed tomography (CT) demonstrated reversal of fatty infiltration of the liver are described. The rapid reversibility of fatty infiltration can be useful in monitoring alcoholics with fatty livers. Focal fatty infiltration can mimic focal hepatic lesions and repeat scans can be utilized to assess changes in CT attenuation values when this condition is suspected

  2. ABRUPT LONGITUDINAL MAGNETIC FIELD CHANGES IN FLARING ACTIVE REGIONS

    International Nuclear Information System (INIS)

    Petrie, G. J. D.; Sudol, J. J.

    2010-01-01

    We characterize the changes in the longitudinal photospheric magnetic field during 38 X-class and 39 M-class flares within 65 0 of disk center using 1 minute GONG magnetograms. In all 77 cases, we identify at least one site in the flaring active region where clear, permanent, stepwise field changes occurred. The median duration of the field changes was about 15 minutes and was approximately equal for X-class and for M-class flares. The absolute values of the field changes ranged from the detection limit of ∼10 G to as high as ∼450 G in two exceptional cases. The median value was 69 G. Field changes were significantly stronger for X-class than for M-class flares and for limb flares than for disk-center flares. Longitudinal field changes less than 100 G tended to decrease longitudinal field strengths, both close to disk center and close to the limb, while field changes greater than 100 G showed no such pattern. Likewise, longitudinal flux strengths tended to decrease during flares. Flux changes, particularly net flux changes near disk center, correlated better than local field changes with GOES peak X-ray flux. The strongest longitudinal field and flux changes occurred in flares observed close to the limb. We estimate the change of Lorentz force associated with each flare and find that this is large enough in some cases to power seismic waves. We find that longitudinal field decreases would likely outnumber increases at all parts of the solar disk within 65 0 of disk center, as in our observations, if photospheric field tilts increase during flares as predicted by Hudson et al.

  3. A novel automated device for rapid nucleic acid extraction utilizing a zigzag motion of magnetic silica beads

    International Nuclear Information System (INIS)

    Yamaguchi, Akemi; Matsuda, Kazuyuki; Uehara, Masayuki; Honda, Takayuki; Saito, Yasunori

    2016-01-01

    We report a novel automated device for nucleic acid extraction, which consists of a mechanical control system and a disposable cassette. The cassette is composed of a bottle, a capillary tube, and a chamber. After sample injection in the bottle, the sample is lysed, and nucleic acids are adsorbed on the surface of magnetic silica beads. These magnetic beads are transported and are vibrated through the washing reagents in the capillary tube under the control of the mechanical control system, and thus, the nucleic acid is purified without centrifugation. The purified nucleic acid is automatically extracted in 3 min for the polymerase chain reaction (PCR). The nucleic acid extraction is dependent on the transport speed and the vibration frequency of the magnetic beads, and optimizing these two parameters provided better PCR efficiency than the conventional manual procedure. There was no difference between the detection limits of our novel device and that of the conventional manual procedure. We have already developed the droplet-PCR machine, which can amplify and detect specific nucleic acids rapidly and automatically. Connecting the droplet-PCR machine to our novel automated extraction device enables PCR analysis within 15 min, and this system can be made available as a point-of-care testing in clinics as well as general hospitals. - Highlights: • Automatic nucleic acid extraction is performed in 3 min. • Zigzag motion of magnetic silica beads yields rapid and efficient extraction. • The present our device provides better performance than the conventional procedure.

  4. 31 P magnetic resonance fingerprinting for rapid quantification of creatine kinase reaction rate in vivo.

    Science.gov (United States)

    Wang, Charlie Y; Liu, Yuchi; Huang, Shuying; Griswold, Mark A; Seiberlich, Nicole; Yu, Xin

    2017-12-01

    The purpose of this work was to develop a 31 P spectroscopic magnetic resonance fingerprinting (MRF) method for fast quantification of the chemical exchange rate between phosphocreatine (PCr) and adenosine triphosphate (ATP) via creatine kinase (CK). A 31 P MRF sequence (CK-MRF) was developed to quantify the forward rate constant of ATP synthesis via CK ( kfCK), the T 1 relaxation time of PCr ( T1PCr), and the PCr-to-ATP concentration ratio ( MRPCr). The CK-MRF sequence used a balanced steady-state free precession (bSSFP)-type excitation with ramped flip angles and a unique saturation scheme sensitive to the exchange between PCr and γATP. Parameter estimation was accomplished by matching the acquired signals to a dictionary generated using the Bloch-McConnell equation. Simulation studies were performed to examine the susceptibility of the CK-MRF method to several potential error sources. The accuracy of nonlocalized CK-MRF measurements before and after an ischemia-reperfusion (IR) protocol was compared with the magnetization transfer (MT-MRS) method in rat hindlimb at 9.4 T (n = 14). The reproducibility of CK-MRF was also assessed by comparing CK-MRF measurements with both MT-MRS (n = 17) and four angle saturation transfer (FAST) (n = 7). Simulation results showed that CK-MRF quantification of kfCK was robust, with less than 5% error in the presence of model inaccuracies including dictionary resolution, metabolite T 2 values, inorganic phosphate metabolism, and B 1 miscalibration. Estimation of kfCK by CK-MRF (0.38 ± 0.02 s -1 at baseline and 0.42 ± 0.03 s -1 post-IR) showed strong agreement with MT-MRS (0.39 ± 0.03 s -1 at baseline and 0.44 ± 0.04 s -1 post-IR). kfCK estimation was also similar between CK-MRF and FAST (0.38 ± 0.02 s -1 for CK-MRF and 0.38 ± 0.11 s -1 for FAST). The coefficient of variation from 20 s CK-MRF quantification of kfCK was 42% of that by 150 s MT-MRS acquisition and was 12% of that by 20 s FAST

  5. The magnetic shield design and simulation of an X-ray spectrometer for Chang'E mission

    International Nuclear Information System (INIS)

    Zhang Jiayu; Wang Huanyu; Zhang Chengmo; Yang Jiawei; Liang Xiaohua; Wang Jinzhou; Cao Xuelei; Gao Min; Cui Xingzhu; Peng Wenxi

    2008-01-01

    Basic design methods about the magnetic shield of an X-ray spectrometer for Chang'E Mission were introduced in this paper. The real magnetic field distribution was obtained through the measure experiment, and according to the measure results, the simulation to evaluate the magnetic shield effect was carded on. The results showed that the collimator can play a good role in magnetic shield to the electron. (authors)

  6. Rapid stress-induced transcriptomic changes in the brain depend on beta-adrenergic signaling.

    Science.gov (United States)

    Roszkowski, Martin; Manuella, Francesca; von Ziegler, Lukas; Durán-Pacheco, Gonzalo; Moreau, Jean-Luc; Mansuy, Isabelle M; Bohacek, Johannes

    2016-08-01

    Acute exposure to stressful experiences can rapidly increase anxiety and cause neuropsychiatric disorders. The effects of stress result in part from the release of neurotransmitters and hormones, which regulate gene expression in different brain regions. The fast neuroendocrine response to stress is largely mediated by norepinephrine (NE) and corticotropin releasing hormone (CRH), followed by a slower and more sustained release of corticosterone. While corticosterone is an important regulator of gene expression, it is not clear which stress-signals contribute to the rapid regulation of gene expression observed immediately after stress exposure. Here, we demonstrate in mice that 45 min after an acute swim stress challenge, large changes in gene expression occur across the transcriptome in the hippocampus, a region sensitive to the effects of stress. We identify multiple candidate genes that are rapidly and transiently altered in both males and females. Using a pharmacological approach, we show that most of these rapidly induced genes are regulated by NE through β-adrenergic receptor signaling. We find that CRH and corticosterone can also contribute to rapid changes in gene expression, although these effects appear to be restricted to fewer genes. These results newly reveal a widespread impact of NE on the transcriptome and identify novel genes associated with stress and adrenergic signaling. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Integrated ocean management as a strategy to meet rapid climate change: the Norwegian case.

    Science.gov (United States)

    Hoel, Alf Håkon; Olsen, Erik

    2012-02-01

    The prospects of rapid climate change and the potential existence of tipping points in marine ecosystems where nonlinear change may result from them being overstepped, raises the question of strategies for coping with ecosystem change. There is broad agreement that the combined forces of climate change, pollution and increasing economic activities necessitates more comprehensive approaches to oceans management, centering on the concept of ecosystem-based oceans management. This article addresses the Norwegian experience in introducing integrated, ecosystem-based oceans management, emphasizing how climate change, seen as a major long-term driver of change in ecosystems, is addressed in management plans. Understanding the direct effects of climate variability and change on ecosystems and indirect effects on human activities is essential for adaptive planning to be useful in the long-term management of the marine environment.

  8. A bioinspired color-changing polystyrene microarray as a rapid qualitative sensor for methanol and ethanol

    International Nuclear Information System (INIS)

    Kuo, Wen-Kai; Weng, Hsueh-Ping; Hsu, Jyun-Jheng; Yu, Hsin Her

    2016-01-01

    Polystyrene (PS) microspheres were synthesized by emulsifier-free emulsion polymerization and arranged in an array of closely packed, opal-like photonic crystals by slow self-assembly through dip-coating. This periodic array of PS microspheres was then employed as a rapid qualitative sensor for methanol and ethanol. Both solvents could be detected rapidly based on the routes of their reflection coordinates in the chromaticity diagram or directly by the naked eye on the basis of the change in color within 1 min once a solvent sample had been placed on the PS photochromic sensor. This opal-like PS sensor can thus not only be employed as a rapid sensor for methanol and ethanol but can also be used as a powerful tool for the fast screening of illicit drugs and toxic chemicals during forensic investigations. - Highlights: • Opal-like array of polystyrene (PS) microspheres is synthesized by self-assembly. • This periodic PS array is used as a rapid sensor for methanol and ethanol. • Solvents are detected by routes of reflection coordinates in chromaticity diagram. • They are also detected directly by naked eye based on change in color of sensor. • The color change is irreversible for methanol but reversible for ethanol.

  9. A bioinspired color-changing polystyrene microarray as a rapid qualitative sensor for methanol and ethanol

    Energy Technology Data Exchange (ETDEWEB)

    Kuo, Wen-Kai, E-mail: wkkuo@nfu.edu.tw [Graduate Institute of Electro-Optical and Materials Science, National Formosa University, 64 Wenhua Road, Huwei, Yunlin 63208, Taiwan (China); Weng, Hsueh-Ping, E-mail: sherry.weng7949@gmail.com [Graduate Institute of Electro-Optical and Materials Science, National Formosa University, 64 Wenhua Road, Huwei, Yunlin 63208, Taiwan (China); Hsu, Jyun-Jheng, E-mail: k88520x@gmail.com [Graduate Institute of Electro-Optical and Materials Science, National Formosa University, 64 Wenhua Road, Huwei, Yunlin 63208, Taiwan (China); Yu, Hsin Her, E-mail: hhyu@nfu.edu.tw [Department of Biotechnology, National Formosa University, 64 Wenhua Road, Huwei, Yunlin 63208, Taiwan (China)

    2016-04-15

    Polystyrene (PS) microspheres were synthesized by emulsifier-free emulsion polymerization and arranged in an array of closely packed, opal-like photonic crystals by slow self-assembly through dip-coating. This periodic array of PS microspheres was then employed as a rapid qualitative sensor for methanol and ethanol. Both solvents could be detected rapidly based on the routes of their reflection coordinates in the chromaticity diagram or directly by the naked eye on the basis of the change in color within 1 min once a solvent sample had been placed on the PS photochromic sensor. This opal-like PS sensor can thus not only be employed as a rapid sensor for methanol and ethanol but can also be used as a powerful tool for the fast screening of illicit drugs and toxic chemicals during forensic investigations. - Highlights: • Opal-like array of polystyrene (PS) microspheres is synthesized by self-assembly. • This periodic PS array is used as a rapid sensor for methanol and ethanol. • Solvents are detected by routes of reflection coordinates in chromaticity diagram. • They are also detected directly by naked eye based on change in color of sensor. • The color change is irreversible for methanol but reversible for ethanol.

  10. Magnetic field topology and chemical abundance distributions of the young, rapidly rotating, chemically peculiar star HR 5624

    Science.gov (United States)

    Kochukhov, O.; Silvester, J.; Bailey, J. D.; Landstreet, J. D.; Wade, G. A.

    2017-09-01

    Context. The young, rapidly rotating Bp star HR 5624 (HD 133880) shows an unusually strong non-sinusoidal variability of its longitudinal magnetic field. This behaviour was previously interpreted as the signature of an exceptionally strong, quadrupole-dominated surface magnetic field geometry. Aims: We studied the magnetic field structure and chemical abundance distributions of HR 5624 with the aim to verify the unusual quadrupolar nature of its magnetic field and to investigate correlations between the field topology and chemical spots. Methods: We analysed high-resolution, time series Stokes parameter spectra of HR 5624 with the help of a magnetic Doppler imaging inversion code based on detailed polarised radiative transfer modelling of the line profiles. Results: We refined the stellar parameters, revised the rotational period, and obtained new longitudinal magnetic field measurements. Our magnetic Doppler inversions reveal that the field structure of HR 5624 is considerably simpler and the field strength is much lower than proposed by previous studies. We find a maximum local field strength of 12 kG and a mean field strength of 4 kG, which is about a factor of three weaker than predicted by quadrupolar field models. Our model implies that overall large-scale field topology of HR 5624 is better described as a distorted, asymmetric dipole rather than an axisymmetric quadrupole. The chemical abundance maps of Mg, Si, Ti, Cr, Fe, and Nd obtained in our study are characterised by large-scale, high-contrast abundance patterns. These structures correlate weakly with the magnetic field geometry and, in particular, show no distinct element concentrations in the horizontal field regions predicted by theoretical atomic diffusion calculations. Conclusions: We conclude that the surface magnetic field topology of HR 5624 is not as unusual as previously proposed. Considering these results together with other recent magnetic mapping analyses of early-type stars suggests that

  11. Magnetic resonance imaging characteristics of fibrocystic change of the breast.

    Science.gov (United States)

    van den Bosch, Maurice A A J; Daniel, Bruce L; Mariano, Michelle N; Nowels, Kent N; Birdwell, Robyn L; Fong, Kathy J; Desmond, Pam S; Plevritis, Sylvia; Stables, Lara A; Zakhour, Marowan; Herfkens, Robert J; Ikeda, Debra M

    2005-07-01

    The objective of this study was to identify magnetic resonance imaging (MRI) characteristics of fibrocystic change (FCC) of the breast. Fourteen patients with a histopathologic diagnosis of solitary FCC of the breast underwent x-ray mammography and MRI of the breast. Three experienced breast imaging radiologists retrospectively reviewed the MRI findings and categorized the lesions on morphologic and kinetic criteria according to the ACR BI-RADS-MRI Lexicon. The most striking morphologic feature of fibrocystic change was nonmass-like regional enhancement found in 6 of 14 (43%) FCC lesions. Based on morphologic criteria alone, 12 of 14 (86%) lesions were correctly classified as benign. According to analysis of the time-intensity curves, 10 of 14 (71%) FCC lesions were correctly classified as benign. Although FCC has a wide spectrum of morphologic and kinetic features on MRI, it most often presents as a mass or a nonmass-like regional enhancing lesion with benign enhancement kinetics.

  12. Rapid and sensitive electrochemiluminescence detection of rotavirus by magnetic primer based reverse transcription-polymerase chain reaction

    International Nuclear Information System (INIS)

    Zhan Fangfang; Zhou Xiaoming; Xing Da

    2013-01-01

    Graphical abstract: In this work, we have developed and demonstrated a magnetic primer based RT-PCR assay for ECL detection of rotavirus. In the presence of two functional primers (magnetic primer and TBR-primer) and PCR reagents, cDNA from RT was amplified directly onto MPs during PCR cycles of denaturation, annealing and extension. The resulting MPs–TBR complexes were easily loaded on the electrode surface and produced a concentrated ECL signal. The figure shows the schematic illustration of magnetic primer RT-PCR based ECL assay for rotavirus detection. Highlights: ► A novel method for detection of rotavirus has been developed. ► In the presence of magnetic primer, TBR-primer and PCR reagents, cDNA form RT was amplified directly onto MPs. ► To obtain the best sensing and efficient performance, important parameters associated with the efficiency were investigated carefully. ► The proposed method will find numerous applications in food safety field and clinical diagnosis. - Abstract: A novel method for detection of rotavirus has been developed by integrating magnetic primer based reverse transcription-polymerase chain reaction (RT-PCR) with electrochemiluminescence (ECL) detection. This is realized by accomplishing RT of rotavirus RNA in traditional way and performing PCR of the resulting cDNA fragment on the surface of magnetic particles (MPs). In order to implement PCR on MPs and achieve rapid ECL detection, forward and reverse primers are bounded to MPs and tris-(2,2′-bipyridyl) ruthenium (TBR), respectively. After RT-PCR amplification, the TBR labels are directly enriched onto the surface of MPs. Then the MPs–TBR complexes can be loaded on the electrode surface and analyzed by magnetic ECL platform without any post-modification or post-incubation process. So some laborious manual operations can be avoided to achieve rapid yet sensitive detection. In this study, rotavirus in fecal specimens was successfully detected within 1.5 h. Experimental

  13. Rapid and sensitive electrochemiluminescence detection of rotavirus by magnetic primer based reverse transcription-polymerase chain reaction

    Energy Technology Data Exchange (ETDEWEB)

    Zhan Fangfang; Zhou Xiaoming [MOE Key Laboratory of Laser Life Science and Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou 510631 (China); Xing Da, E-mail: xingda@scnu.edu.cn [MOE Key Laboratory of Laser Life Science and Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou 510631 (China)

    2013-01-25

    Graphical abstract: In this work, we have developed and demonstrated a magnetic primer based RT-PCR assay for ECL detection of rotavirus. In the presence of two functional primers (magnetic primer and TBR-primer) and PCR reagents, cDNA from RT was amplified directly onto MPs during PCR cycles of denaturation, annealing and extension. The resulting MPs-TBR complexes were easily loaded on the electrode surface and produced a concentrated ECL signal. The figure shows the schematic illustration of magnetic primer RT-PCR based ECL assay for rotavirus detection. Highlights: Black-Right-Pointing-Pointer A novel method for detection of rotavirus has been developed. Black-Right-Pointing-Pointer In the presence of magnetic primer, TBR-primer and PCR reagents, cDNA form RT was amplified directly onto MPs. Black-Right-Pointing-Pointer To obtain the best sensing and efficient performance, important parameters associated with the efficiency were investigated carefully. Black-Right-Pointing-Pointer The proposed method will find numerous applications in food safety field and clinical diagnosis. - Abstract: A novel method for detection of rotavirus has been developed by integrating magnetic primer based reverse transcription-polymerase chain reaction (RT-PCR) with electrochemiluminescence (ECL) detection. This is realized by accomplishing RT of rotavirus RNA in traditional way and performing PCR of the resulting cDNA fragment on the surface of magnetic particles (MPs). In order to implement PCR on MPs and achieve rapid ECL detection, forward and reverse primers are bounded to MPs and tris-(2,2 Prime -bipyridyl) ruthenium (TBR), respectively. After RT-PCR amplification, the TBR labels are directly enriched onto the surface of MPs. Then the MPs-TBR complexes can be loaded on the electrode surface and analyzed by magnetic ECL platform without any post-modification or post-incubation process. So some laborious manual operations can be avoided to achieve rapid yet sensitive detection

  14. Scaling of the magnetic entropy change of Fe3−xMnxSi

    International Nuclear Information System (INIS)

    Said, M.R.; Hamam, Y.A.; Abu-Aljarayesh, I.

    2014-01-01

    The magnetic entropy change of Fe 3−x Mn x Si (for x=1.15, 1.3 and 1.5) has been extracted from isothermal magnetization measurements near the Curie temperature. We used the scaling hypotheses of the thermodynamic potentials to scale the magnetic entropy change to a single universal curve for each sample. The effect of the exchange field and the Curie temperature on the maximum entropy change is discussed. - Highlights: • The maximum of the magnetic entropy change occurs at temperatures T>T C . • The exchange field enhances the magnetic entropy change. • The magnetic entropy change at T C is inversely proportional to T C . • Scaling hypothesis is used to scale the magnetic entropy change

  15. Changes in the High-Latitude Topside Ionospheric Vertical Electron-Density Profiles in Response to Solar-Wind Perturbations During Large Magnetic Storms

    Science.gov (United States)

    Benson, Robert F.; Fainberg, Joseph; Osherovich, Vladimir; Truhlik, Vladimir; Wang, Yongli; Arbacher, Becca

    2011-01-01

    The latest results from an investigation to establish links between solar-wind and topside-ionospheric parameters will be presented including a case where high-latitude topside electron-density Ne(h) profiles indicated dramatic rapid changes in the scale height during the main phase of a large magnetic storm (Dst wind data obtained from the NASA OMNIWeb database indicated that the magnetic storm was due to a magnetic cloud. This event is one of several large magnetic storms being investigated during the interval from 1965 to 1984 when both solar-wind and digital topside ionograms, from either Alouette-2, ISIS-1, or ISIS-2, are potentially available.

  16. Rapid Hip Osteoarthritis Development in a Patient with Anterior Acetabular Cyst with Sagittal Alignment Change

    Directory of Open Access Journals (Sweden)

    Yasuhiro Homma

    2014-01-01

    Full Text Available Rapidly destructive coxarthrosis (RDC is rare and develops unusual clinical course. Recent studies suggest multiple possible mechanisms of the development of RDC. However the exact mechanism of RDC is still not clear. The difficulty of the study on RDC is attributed to its rareness and the fact that the data before the onset of RDC is normally unavailable. In this report, we presented the patient having the radiographic data before the onset who had rapid osteoarthritis (OA development after contralateral THA, which meets the current criteria of RDC. We thought that the increased posterior tilt of the pelvis after THA reinforced the stress concentration at pre-existed anterior acetabular cyst, thereby the destruction of the cyst was occurred. As a result the rapid OA was developed. We think that there is the case of rapid osteoarthritis developing due to alternating load concentration by posterior pelvic tilt on preexisting anterior acetabular cyst such as our patient among the cases diagnosed as RDC without any identifiable etiology. The recognition of sagittal alignment changes and anterior acetabular cyst may play important role in prediction and prevention of the rapid hip osteoarthritis development similar to RDC.

  17. Effects of high latitude protected areas on bird communities under rapid climate change.

    Science.gov (United States)

    Santangeli, Andrea; Rajasärkkä, Ari; Lehikoinen, Aleksi

    2017-06-01

    Anthropogenic climate change is rapidly becoming one of the main threats to biodiversity, along with other threats triggered by human-driven land-use change. Species are already responding to climate change by shifting their distributions polewards. This shift may create a spatial mismatch between dynamic species distributions and static protected areas (PAs). As protected areas represent one of the main pillars for preserving biodiversity today and in the future, it is important to assess their contribution in sheltering the biodiversity communities, they were designated to protect. A recent development to investigate climate-driven impacts on biological communities is represented by the community temperature index (CTI). CTI provides a measure of the relative temperature average of a community in a specific assemblage. CTI value will be higher for assemblages dominated by warm species compared with those dominated by cold-dwelling species. We here model changes in the CTI of Finnish bird assemblages, as well as changes in species densities, within and outside of PAs during the past four decades in a large boreal landscape under rapid change. We show that CTI has markedly increased over time across Finland, with this change being similar within and outside PAs and five to seven times slower than the temperature increase. Moreover, CTI has been constantly lower within than outside of PAs, and PAs still support communities, which show colder thermal index than those outside of PAs in the 1970s and 1980s. This result can be explained by the higher relative density of northern species within PAs than outside. Overall, our results provide some, albeit inconclusive, evidence that PAs may play a role in supporting the community of northern species. Results also suggest that communities are, however, shifting rapidly, both inside and outside of PAs, highlighting the need for adjusting conservation measures before it is too late. © 2016 John Wiley & Sons Ltd.

  18. New type of Piezoresistive Pressure Sensors for Environments with Rapidly Changing Temperature

    Directory of Open Access Journals (Sweden)

    Tykhan Myroslav

    2017-03-01

    Full Text Available The theoretical aspects of a new type of piezo-resistive pressure sensors for environments with rapidly changing temperatures are presented. The idea is that the sensor has two identical diaphragms which have different coefficients of linear thermal expansion. Therefore, when measuring pressure in environments with variable temperature, the diaphragms will have different deflection. This difference can be used to make appropriate correction of the sensor output signal and, thus, to increase accuracy of measurement. Since physical principles of sensors operation enable fast correction of the output signal, the sensor can be used in environments with rapidly changing temperature, which is its essential advantage. The paper presents practical implementation of the proposed theoretical aspects and the results of testing the developed sensor.

  19. Environmental impacts of rapid water level changes; Miljoekonsekvenser av raske vannstandsendringer

    Energy Technology Data Exchange (ETDEWEB)

    Arnekleiv, Jo Vegar; Bakken, Tor Haakon; Bogen, Jim; Boensnes, Truls Erik; Elster, Margrethe; Harby, Atle; Kutznetsova, Yulia; Saltveit, Svein Jakob; Sauterleute, Julian; Stickler, Morten; Sundt, Haakon; Tjomsland, Torulv; Ugedal, Ola

    2012-07-01

    This report summarizes the state of knowledge of the environmental impacts of power driving and rapid water level changes and describes possible mitigation measures. The report assesses the environmental effects of possible increased power installation in Mauranger and Tonstad power plants, based on existing data and knowledge. At Straumsmo plants in Barduelva there are collected some physical data and the environmental impact of existing power driving is considered. (eb)

  20. Importance of magnetic resonance imaging in patients with fibrocystic changes.

    Science.gov (United States)

    Kiyak, G; Asik, E; Yazgan, A

    2011-01-01

    A proper detection of atypical epithelial hyperplasia (component of FCC) without missing the coexistent malign disease is the main problem in evaluating the FCC-affected patients. For some patients, it is not enough to use only mammography and ultrasonography in pursuit or decision biopsy. Magnetic resonance imaging (MRI) may be important in these patients. Nevertheless, the MRI features of FCC are not clearly known because there are very few studies specifically focused on FCC. Studies reporting on MRI of breast fibrocystic changes are very scarce and their MRI findings are not clearly known. The aim of this study was to determine the MRI characteristics of fibrocystic changes. Twenty-six patients with pathologically proven fibrocystic changes of the breast were retrospectively reviewed. The MRI study was performed using 1.5 T MR scanner with a phase array bilateral breast coil. The imaging protocol consisted of pre-contrast T1-weighted imaging and bilateral dynamic 3D contrast-enhanced imaging. The morphologic and kinetic features of fibrocystic changes on MRI were evaluated. Twenty-four patients showed benign enhancement kinetics (type 1), while 2 patients showed malignant enhancement kinetics (type 2). To our knowledge, the analysis of enhancement kinetics may be more useful in identifying atypical epithelial hyperplasia and cancer from other breast lesions provided that corrections are made for the true phase of menstrual cycle (Tab. 1, Fig. 1, Ref. 10).

  1. Rapid magnetic solid-phase extraction based on monodisperse magnetic single-crystal ferrite nanoparticles for the determination of free fatty acid content in edible oils.

    Science.gov (United States)

    Wei, Fang; Zhao, Qin; Lv, Xin; Dong, Xu-Yan; Feng, Yu-Qi; Chen, Hong

    2013-01-09

    This study proposes a rapid magnetic solid-phase extraction (MSPE) based on monodisperse magnetic single-crystal ferrite (Fe(3)O(4)) nanoparticles (NPs) for determining the quantities of eight free fatty acids (FFAs), including palmitic acid (C16:0), stearic acid (C18:0), oleic acid (C18:1), linoleic acid (C18:2), linolenic acid (C18:3), arachidic acid (C20:0), eicosenoic acid (C20:1), and behenic acid (C22:0) in oil. The amine-functionalized mesoporous Fe(3)O(4) magnetic NPs were applied as a sorbent for MSPE of FFAs from oil samples in a process that is based on hydrophilic interaction. The extraction can be completed rapidly in a dispersive mode with the aid of vigorous vortex. Additional tedious processing steps such as centrifugation and evaporation of organic solvent were not necessary with this procedure. Furthermore, esterification of FFAs can be accomplished during the desorption procedure by using methanol/sulfuric acid (99:1, v/v) as the desorption solvent. Several parameters affecting the extraction efficiency were investigated, including the matrix solvent for extraction, the desorption solvent and desorption time, and the amount of sorbent and extraction time. The pretreatment process was rapid under optimal conditions, being accomplished within 15 min. When coupled with gas chromatography-flame ionization detection (GC-FID), a rapid, simple, and convenient MSPE-GC-FID method for the determination of FFAs in oil samples was established with a total analysis time within 25 min. The limits of detection for the target FFAs were found to be 7.22-26.26 ng/mL. Recoveries in oil samples were in the range of 81.33-117.75%, with RSDs of <6.4% (intraday) and <6.9% (interday). This method was applied successfully to the analysis of dynamic FFA formation in four types of edible oils subjected to an accelerated storage test. The simple, rapid, and cost-effective method developed in the current study offers a potential application for the extraction and

  2. Observation of reversible, rapid changes in drug susceptibility of hypoxic tumor cells in a microfluidic device

    Energy Technology Data Exchange (ETDEWEB)

    Germain, Todd; Ansari, Megan; Pappas, Dimitri, E-mail: d.pappas@ttu.edu

    2016-09-14

    Hypoxia is a major stimulus for increased drug resistance and for survival of tumor cells. Work from our group and others has shown that hypoxia increases resistance to anti-cancer compounds, radiation, and other damage-pathway cytotoxic agents. In this work we utilize a microfluidic culture system capable of rapid switching of local oxygen concentrations to determine changes in drug resistance in prostate cancer cells. We observed rapid adaptation to hypoxia, with drug resistance to 2 μM staurosporine established within 30 min of hypoxia. Annexin-V/Sytox Green apoptosis assays over 9 h showed 78.0% viability, compared to 84.5% viability in control cells (normoxic cells with no staurosporine). Normoxic cells exposed to the same staurosporine concentration had a viability of 48.6% after 9 h. Hypoxia adaptation was rapid and reversible, with Hypoxic cells treated with 20% oxygen for 30 min responding to staurosporine with 51.6% viability after drug treatment for 9 h. Induction of apoptosis through the receptor-mediated pathway, which bypasses anti-apoptosis mechanisms induced by hypoxia, resulted in 39.4 ± 7% cell viability. The rapid reversibility indicates co-treatment of oxygen with anti-cancer compounds may be a potential therapeutic target. - Highlights: • Microfluidic system switches rapidly between normoxia and hypoxia (5 min). • Observation of rapid adaptation of PC3 cells to hypoxia and normoxia (30 min). • Drug susceptibility in tumor cells restored after chip switched to normoxia for 30 min.

  3. Rapid liquid phase sintered Mn doped BiFeO3 ceramics with enhanced polarization and weak magnetization

    Science.gov (United States)

    Kumar, Manoj; Yadav, K. L.

    2007-12-01

    Single-phase BiFe1-xMnxO3 multiferroic ceramics have been synthesized by rapid liquid phase sintering method to study the influence of Mn substitution on their crystal structure, dielectric, magnetic, and ferroelectric behaviors. From XRD analysis it is seen that Mn substitution does not affect the crystal structure of the BiFe1-xMnxO3 system. An enhancement in magnetization was observed for BiFe1-xMnxO3 ceramics. However, the ferooelectric hysteresis loops were not really saturated, we observed a spontaneous polarization of 10.23μC /cm2 under the applied field of 42kV/cm and remanent polarization of 3.99μC/cm2 for x =0.3 ceramic.

  4. Variation of particle exhaust with changes in divertor magnetic balance

    International Nuclear Information System (INIS)

    Petrie, T.W.; Allen, S.L.; Brooks, N.H.

    2006-01-01

    Recent experiments on DIII-D point to the importance of two factors in determining how effectively the deuterium particle inventory in a tokamak plasma can be controlled through pumping at the divertor target(s): (1) the divertor magnetic balance, i.e. the degree to which the divertor topology is single-null or double-null (DN) and (2) the direction of the of B x ∇B ion drift with respect to the X-point(s). Changes in divertor magnetic balance near the DN shape have a much stronger effect on the particle exhaust rate at the inner divertor target(s) than on the particle exhaust rate at the outer divertor target(s). The particle exhaust rate for the DN shape is strongest at the outer strike point opposite the B x ∇B ion particle drift direction. Our data suggests that the presence of B x ∇B and E x B ion particle drifts in the scrape-off layer and divertor(s) play an important role in the particle exhaust rates of DN and near-DN plasmas. Particle exhaust rates are shown to depend strongly on the edge (pedestal) density. These results have implications for particle control in ITER and other future tokamaks

  5. Rapid extraction of genomic DNA from saliva for HLA typing on microarray based on magnetic nanobeads

    Energy Technology Data Exchange (ETDEWEB)

    Xie Xin; Zhang Xu E-mail: shinezhang@hotmail.com; Yu Bingbin; Gao Huafang; Zhang Huan; Fei Weiyang

    2004-09-01

    A series of simplified protocols are developed for extracting genomic DNA from saliva by using the magnetic nanobeads as absorbents. In these protocols, both the enrichment of the target cells and the adsorption of DNA can be achieved simultaneously by our functionally modified magnetic beads in one step, and the DNA-nanobeads complex can be used as PCR templates. HLA typing based on an oligonucleotide array was conducted by hybridization with the PCR products. The result shows that the protocols are robust and sensitive.

  6. RAPID SPECTRAL CHANGES OF CYGNUS X-1 IN THE LOW/HARD STATE WITH SUZAKU

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, S.; Makishima, K. [Cosmic Radiation Laboratory, Institute of Physical and Chemical Research (RIKEN), Wako, Saitama 351-0198 (Japan); Negoro, H. [Department of Physics, College of Science and Technology, Nihon University, 1-8 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8308 (Japan); Torii, S.; Noda, H. [Department of Physics, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Mineshige, S. [Department of Astronomy, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502 (Japan)

    2013-04-20

    Rapid spectral changes in the hard X-ray on a timescale down to {approx}0.1 s are studied by applying a ''shot analysis'' technique to the Suzaku observations of the black hole binary Cygnus X-1, performed on 2008 April 18 during the low/hard state. We successfully obtained the shot profiles, covering 10-200 keV with the Suzaku HXD-PIN and HXD-GSO detector. It is notable that the 100-200 keV shot profile is acquired for the first time owing to the HXD-GSO detector. The intensity changes in a time-symmetric way, though the hardness changes in a time-asymmetric way. When the shot-phase-resolved spectra are quantified with the Compton model, the Compton y-parameter and the electron temperature are found to decrease gradually through the rising phase of the shot, while the optical depth appears to increase. All the parameters return to their time-averaged values immediately within 0.1 s past the shot peak. We have not only confirmed this feature previously found in energies below {approx}60 keV, but also found that the spectral change is more prominent in energies above {approx}100 keV, implying the existence of some instant mechanism for direct entropy production. We discuss possible interpretations of the rapid spectral changes in the hard X-ray band.

  7. EEG-guided transcranial magnetic stimulation reveals rapid shifts in motor cortical excitability during the human sleep slow oscillation

    DEFF Research Database (Denmark)

    Bergmann, Til O; Mölle, Matthias; Schmidt, Marlit A

    2012-01-01

    Evoked cortical responses do not follow a rigid input–output function but are dynamically shaped by intrinsic neural properties at the time of stimulation. Recent research has emphasized the role of oscillatory activity in determining cortical excitability. Here we employed EEG-guided transcranial......, closely resembling a spontaneous SO. However, both MEPs and TEPs were consistently larger when evoked during SO up-states than during down-states, and ampliudes within each SO state depended on the actual EEG potential at the time and site of stimulation. These results provide first-time evidence...... magnetic stimulation (TMS) during non-rapid eye movement sleep to examine whether the spontaneous

  8. [Developmental changes of rapid automatized naming and Hiragana reading of Japanese in elementary-school children].

    Science.gov (United States)

    Kobayashi, Tomoka; Inagaki, Masumi; Gunji, Atsuko; Yatabe, Kiyomi; Kita, Yosuke; Kaga, Makiko; Gotoh, Takaaki; Koike, Toshihide

    2011-11-01

    Two hundred and seven Japanese elementary school children aged from 6 (Grade 1) to 12 (Grade 6) years old were tested for their abilities to name numbers and pictured objects along with reading Hiragana characters and words. These children all showed typical development and their classroom teachers judged that they were not having any problems with reading or writing. The children were randomly divided into two groups, the first group was assigned to two naming tasks;the rapid automatized naming (RAN) of "numbers" and "pictured objects," the second group was assigned to two rapid alternative stimulus (RAS) naming tasks using numbers and pictured objects. All children were asked to perform two reading tasks that were written in Hiragana script: single mora reading task and four syllable word reading task. The total articulation time for naming and reading and performance in terms of accuracy were measured for each task. Developmental changes in these variables were evaluated. The articulation time was significantly longer for the first graders, and it gradually shortened as they moved through to the upper grades in all tasks. The articulation time reached a plateau in the 5th grade for the number naming, while gradual change continued after drastic change in the lower grades for the pictured object naming. The articulation times for the single mora reading and RAN of numbers correlated strongly. The articulation time for the RAS naming was significantly longer compared to that for the RAN, though there were very few errors. The RAS naming showed the highest correlation with the four syllable word reading. This study demonstrated that the performance in rapid automatized naming of numbers and pictures were closely related with performance on reading tasks. Thus Japanese children with reading disorders such as developmental dyslexia should also be evaluated for rapid automatized naming.

  9. Brainstem and cerebellar changes after cerebrovascular accidents: magnetic resonance imaging

    International Nuclear Information System (INIS)

    Uchino, A.; Takase, Y.; Nomiyama, K.; Egashira, R.; Kudo, S.

    2006-01-01

    We illustrate the various types of secondary degeneration in the brainstem and/or cerebellum detected on magnetic resonance (MR) images obtained after cerebrovascular accidents. The changes include: (a) ipsilateral nigral degeneration after striatal infarction; (b) Wallerian degeneration of the pyramidal tract in the brainstem after supratentorial pyramidal tract or motor cortex injury; (c) Wallerian degeneration of the corticopontine tract in the brainstem after frontal lobe infarction; (d) ipsilateral brainstem atrophy and crossed cerebellar atrophy due to an extensive supratentorial lesion; (e) ipsilateral superior cerebellar peduncle atrophy, contralateral rubral degeneration, contralateral inferior olivary degeneration and ipsilateral cerebellar atrophy after dentate nucleus hemorrhage; (f) ipsilateral inferior olivary degeneration after pontine tegmentum hemorrhage; (g) bilateral wallerian degeneration of the pontocerebellar tracts after ventromedial pontine infarction or basis pontis hemorrhage; and (h) ipsilateral cerebellar atrophy after middle cerebellar peduncle hemorrhage. (orig.)

  10. Brainstem and cerebellar changes after cerebrovascular accidents: magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Uchino, A.; Takase, Y.; Nomiyama, K.; Egashira, R.; Kudo, S. [Saga Medical School, Department of Radiology, Saga (Japan)

    2006-03-15

    We illustrate the various types of secondary degeneration in the brainstem and/or cerebellum detected on magnetic resonance (MR) images obtained after cerebrovascular accidents. The changes include: (a) ipsilateral nigral degeneration after striatal infarction; (b) Wallerian degeneration of the pyramidal tract in the brainstem after supratentorial pyramidal tract or motor cortex injury; (c) Wallerian degeneration of the corticopontine tract in the brainstem after frontal lobe infarction; (d) ipsilateral brainstem atrophy and crossed cerebellar atrophy due to an extensive supratentorial lesion; (e) ipsilateral superior cerebellar peduncle atrophy, contralateral rubral degeneration, contralateral inferior olivary degeneration and ipsilateral cerebellar atrophy after dentate nucleus hemorrhage; (f) ipsilateral inferior olivary degeneration after pontine tegmentum hemorrhage; (g) bilateral wallerian degeneration of the pontocerebellar tracts after ventromedial pontine infarction or basis pontis hemorrhage; and (h) ipsilateral cerebellar atrophy after middle cerebellar peduncle hemorrhage. (orig.)

  11. Sequential changes of sodium magnetic resonance images after cerebral hemorrhage

    International Nuclear Information System (INIS)

    Shimizu, T.; Naritomi, H.; Kuriyama, Y.; Sawada, T.

    1992-01-01

    Four patients with cerebral hemorrhage were examined serially from the acute to chronic phase by 1 H magnetic resonance imaging (MRI), 23 Na MRI and computed tomography (CT). At 1-2 days after bleeding, the 23 Na image revealed no visible signal change in the area of hemorrhage, although CT and 1 H images clearly demonstrated the existence of a hematoma in the thalamus or putamen. At 4-7 days after the hemorrhage, the 23 Na images began to exhibit a small increase in signal intensity at the hematoma site, while at 2-3 weeks, a marked increase in 23 Na signal intensity was observed. These findings suggest that the hematoma consisted mainly of a corpuscular component, with a low Na + concentration, with little serum component. 23 Na MRI appears to provide important information for understanding the evoluation of cerebral hemorrhage and for estimating the viability of cells, although its value for diagnosis may not be great. (orig./GDG)

  12. Observation of reversible, rapid changes in drug susceptibility of hypoxic tumor cells in a microfluidic device.

    Science.gov (United States)

    Germain, Todd; Ansari, Megan; Pappas, Dimitri

    2016-09-14

    Hypoxia is a major stimulus for increased drug resistance and for survival of tumor cells. Work from our group and others has shown that hypoxia increases resistance to anti-cancer compounds, radiation, and other damage-pathway cytotoxic agents. In this work we utilize a microfluidic culture system capable of rapid switching of local oxygen concentrations to determine changes in drug resistance in prostate cancer cells. We observed rapid adaptation to hypoxia, with drug resistance to 2 μM staurosporine established within 30 min of hypoxia. Annexin-V/Sytox Green apoptosis assays over 9 h showed 78.0% viability, compared to 84.5% viability in control cells (normoxic cells with no staurosporine). Normoxic cells exposed to the same staurosporine concentration had a viability of 48.6% after 9 h. Hypoxia adaptation was rapid and reversible, with Hypoxic cells treated with 20% oxygen for 30 min responding to staurosporine with 51.6% viability after drug treatment for 9 h. Induction of apoptosis through the receptor-mediated pathway, which bypasses anti-apoptosis mechanisms induced by hypoxia, resulted in 39.4 ± 7% cell viability. The rapid reversibility indicates co-treatment of oxygen with anti-cancer compounds may be a potential therapeutic target. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. MR Measurement Technique of Rapidly Switched Gradient Magnetic Fields in MR Tomography

    Czech Academy of Sciences Publication Activity Database

    Bartušek, Karel; Gescheidtová, E.

    2005-01-01

    Roč. 29, č. 4 (2005), s. 675-686 ISSN 0937-9347 Institutional research plan: CEZ:AV0Z20650511 Keywords : MR tomography * gradiernt magnet ic field * IF method * IFSE method * IFSES method * spin echo Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 0.743, year: 2005

  14. Evolution under changing climates: climatic niche stasis despite rapid evolution in a non-native plant.

    Science.gov (United States)

    Alexander, Jake M

    2013-09-22

    A topic of great current interest is the capacity of populations to adapt genetically to rapidly changing climates, for example by evolving the timing of life-history events, but this is challenging to address experimentally. I use a plant invasion as a model system to tackle this question by combining molecular markers, a common garden experiment and climatic niche modelling. This approach reveals that non-native Lactuca serriola originates primarily from Europe, a climatic subset of its native range, with low rates of admixture from Asia. It has rapidly refilled its climatic niche in the new range, associated with the evolution of flowering phenology to produce clines along climate gradients that mirror those across the native range. Consequently, some non-native plants have evolved development times and grow under climates more extreme than those found in Europe, but not among populations from the native range as a whole. This suggests that many plant populations can adapt rapidly to changed climatic conditions that are already within the climatic niche space occupied by the species elsewhere in its range, but that evolution to conditions outside of this range is more difficult. These findings can also help to explain the prevalence of niche conservatism among non-native species.

  15. Rapid changes in corticospinal excitability during force field adaptation of human walking

    DEFF Research Database (Denmark)

    Barthélemy, Dorothy; Alain, S; Grey, Michael James

    2012-01-01

    measured changes in motor-evoked potentials (MEPs) elicited by transcranial magnetic stimulation (TMS) in the tibialis anterior (TA) muscle before, during, and after subjects adapted to a force field applied to the ankle joint during treadmill walking. When the force field assisted dorsiflexion during...... the swing phase of the step cycle, subjects adapted by decreasing TA EMG activity. In contrast, when the force field resisted dorsiflexion, they increased TA EMG activity. After the force field was removed, normal EMG activity gradually returned over the next 5 min of walking. TA MEPs elicited in the early...... be explained by changes in background TA EMG activity. These effects seemed specific to walking, as similar changes in TA MEP were not seen when seated subjects were tested during static dorsiflexion. These observations suggest that the corticospinal tract contributes to the adaptation of walking...

  16. More rapid climate change promotes evolutionary rescue through selection for increased dispersal distance.

    Science.gov (United States)

    Boeye, Jeroen; Travis, Justin M J; Stoks, Robby; Bonte, Dries

    2013-02-01

    Species can either adapt to new conditions induced by climate change or shift their range in an attempt to track optimal environmental conditions. During current range shifts, species are simultaneously confronted with a second major anthropogenic disturbance, landscape fragmentation. Using individual-based models with a shifting climate window, we examine the effect of different rates of climate change on the evolution of dispersal distances through changes in the genetically determined dispersal kernel. Our results demonstrate that the rate of climate change is positively correlated to the evolved dispersal distances although too fast climate change causes the population to crash. When faced with realistic rates of climate change, greater dispersal distances evolve than those required for the population to keep track of the climate, thereby maximizing population size. Importantly, the greater dispersal distances that evolve when climate change is more rapid, induce evolutionary rescue by facilitating the population in crossing large gaps in the landscape. This could ensure population persistence in case of range shifting in fragmented landscapes. Furthermore, we highlight problems in using invasion speed as a proxy for potential range shifting abilities under climate change.

  17. Rapid area change in pitch-up manoeuvres of small perching birds.

    Science.gov (United States)

    Polet, D T; Rival, D E

    2015-10-26

    Rapid pitch-up has been highlighted as a mechanism to generate large lift and drag during landing manoeuvres. However, pitching rates had not been measured previously in perching birds, and so the direct applicability of computations and experiments to observed behaviour was not known. We measure pitch rates in a small, wild bird (the black-capped chickadee; Poecile atricapillus), and show that these rates are within the parameter range used in experiments. Pitching rates were characterized by the shape change number, a metric comparing the rate of frontal area increase to acceleration. Black-capped chickadees increase the shape change number during perching in direct proportion to their total kinetic and potential energy at the start of the manoeuvre. The linear relationship between dissipated energy and shape change number is in accordance with a simple analytical model developed for two-dimensional pitching and decelerating airfoils. Black-capped chickadees use a wing pitch-up manoeuvre during perching to dissipate energy quickly while maintaining lift and drag through rapid area change. It is suggested that similar pitch-and-decelerate manoeuvres could be used to aid in the controlled, precise landings of small manoeuvrable air vehicles.

  18. Tracking and unpacking rapid Arctic change: Indicators of community health and sustainability in northern Alaska and links to cryospheric change

    Science.gov (United States)

    Eicken, H.; Sam, J. M.; Mueller-stoffels, M.; Lovecraft, A. L.; Fresco, N. L.

    2017-12-01

    Tracking and responding to rapid Arctic change benefits from time series of indicator variables that describe the state of the system and can inform anticipatory action. A key challenge is to identify and monitor sets of indicators that capture relevant variability, trends, and transitions in social-environmental systems. We present findings from participatory scenarios focused on community health and sustainability in northern Alaska. In a series of workshops in 2015 and 2016 (Kotzebue workshop photo shown below), over 50 experts, mostly local, identified determinants of community health and sustainability by 2040 in the Northwest Arctic and North Slope Boroughs, Alaska. Drawing on further research, an initial set of factors and uncertainties was refined and prioritized into a total of 20 key drivers, ranging from governance issues to socio-economic and environmental factors. The research team then developed sets of future projections that describe plausible outcomes by mid-century for each of these drivers. A plausibility and consistency analysis of all pairwise combinations of these projections (following Mueller-Stoffels and Eicken, In: North by 2020 - Perspectives on Alaska's Changing Social-Ecological Systems, University of Alaska Press, 2011) resulted in the identification of robust scenarios. The latter were further reviewed by workshop participants, and a set of indicator variables, including indicators of relevant cryospheric change, was identified to help track trajectories towards plausible future states. Publically accessible recorded data only exist for a subset of the more than 70 indicators, reaching back a few years to several decades. For several indicators, the sampling rate or time series length are insufficient for tracking of and response to change. A core set of variables has been identified that meets indicator requirements and can serve as a tool for Alaska Arctic communities in adapting to or mitigating rapid change affecting community

  19. Rapidly reversible redox transformation in nanophase manganese oxides at room temperature triggered by changes in hydration.

    Science.gov (United States)

    Birkner, Nancy; Navrotsky, Alexandra

    2014-04-29

    Chemisorption of water onto anhydrous nanophase manganese oxide surfaces promotes rapidly reversible redox phase changes as confirmed by calorimetry, X-ray diffraction, and titration for manganese average oxidation state. Surface reduction of bixbyite (Mn2O3) to hausmannite (Mn3O4) occurs in nanoparticles under conditions where no such reactions are seen or expected on grounds of bulk thermodynamics in coarse-grained materials. Additionally, transformation does not occur on nanosurfaces passivated by at least 2% coverage of what is likely an amorphous manganese oxide layer. The transformation is due to thermodynamic control arising from differences in surface energies of the two phases (Mn2O3 and Mn3O4) under wet and dry conditions. Such reversible and rapid transformation near room temperature may affect the behavior of manganese oxides in technological applications and in geologic and environmental settings.

  20. Disseminating Knowledge Through Publication: Magnet® Nurses Changing Practice.

    Science.gov (United States)

    Graystone, Rebecca

    2018-01-01

    Clinical nurses and nurse leaders are inspiring and fostering amazing outcomes. In this column, the new Magnet Recognition Program® director discusses the expectation for dissemination of outcomes from Magnet®-designated organizations building on work presented at the 2017 National Magnet Conference™.

  1. Rapid changes in gene expression direct rapid shifts in intestinal form and function in the Burmese python after feeding

    OpenAIRE

    Andrew, Audra L.; Card, Daren C.; Ruggiero, Robert P.; Schield, Drew R.; Adams, Richard H.; Pollock, David D.; Secor, Stephen M.; Castoe, Todd A.

    2015-01-01

    Snakes provide a unique and valuable model system for studying the extremes of physiological remodeling because of the ability of some species to rapidly upregulate organ form and function upon feeding. The predominant model species used to study such extreme responses has been the Burmese python because of the extreme nature of postfeeding response in this species. We analyzed the Burmese python intestine across a time series, before, during, and after feeding to understand the patterns and ...

  2. One pot synthesis of magnetic graphene/carbon nanotube composites as magnetic dispersive solid-phase extraction adsorbent for rapid determination of oxytetracycline in sewage water.

    Science.gov (United States)

    Sun, Yunyun; Tian, Jing; Wang, Lu; Yan, Hongyuan; Qiao, Fengxia; Qiao, Xiaoqiang

    2015-11-27

    A simple and time-saving one pot synthesis of magnetic graphene/carbon nanotube composites (M-G/CNTs) was developed that could avoid the tedious drying process of graphite oxide, and G/CNTs were modified by Fe3O4 nanoparticles in the reduction procedure. It contributed to a shorten duration of the synthesis process of M-G/CNTs. The obtained M-G/CNTs were characterized and the results indicated that CNTs and Fe3O4 nanoparticles were served as spacer distributing to the layers of graphene, which was beneficial for enlarging surface area and improving extraction efficiency. Moreover, M-G/CNTs showed good magnetic property and outstanding thermal stability. Then M-G/CNTs were applied as adsorbent of magnetic dispersive solid-phase extraction for rapid extraction and determination of oxytetracycline in sewage water. Under the optimum conditions, good linearity was obtained in the range of 20-800ngmL(-1) and the recoveries were ranged from 95.5% to 112.5% with relative standard deviations less than 5.8%. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Mobile magnetic particles as solid-supports for rapid surface-based bioanalysis in continuous flow.

    Science.gov (United States)

    Peyman, Sally A; Iles, Alexander; Pamme, Nicole

    2009-11-07

    An extremely versatile microfluidic device is demonstrated in which multi-step (bio)chemical procedures can be performed in continuous flow. The system operates by generating several co-laminar flow streams, which contain reagents for specific (bio)reactions across a rectangular reaction chamber. Functionalized magnetic microparticles are employed as mobile solid-supports and are pulled from one side of the reaction chamber to the other by use of an external magnetic field. As the particles traverse the co-laminar reagent streams, binding and washing steps are performed on their surface in one operation in continuous flow. The applicability of the platform was first demonstrated by performing a proof-of-principle binding assay between streptavidin coated magnetic particles and biotin in free solution with a limit of detection of 20 ng mL(-1) of free biotin. The system was then applied to a mouse IgG sandwich immunoassay as a first example of a process involving two binding steps and two washing steps, all performed within 60 s, a fraction of the time required for conventional testing.

  4. Microstructure and composition in rapidly quenched NdFeB-based hard magnet alloys

    International Nuclear Information System (INIS)

    Nguyen, T.D.; Krishnan, K.M.; Lewis, L.H.; Zhu, Y.; Welch, D.O.

    1996-01-01

    A detailed study of the microstructure and composition in hot-pressed (MQ-2) and die-upset (MQ-3) magnet alloys based on the Nd 2 Fe 14 B composition, utilizing high resolution and analytical transmission electron microscopy, is reported. The initial magnetic properties of the two samples show different behaviors, which are attributed to the difference in the anisotropy of the grain structure and the grain boundaries. The hot-pressed sample shows faceted grains of the 2-14-1 phase, while die-upset sample shows plate-like grains, together with larger equiaxed grains that contain a speckling of precipitates in the grain interior. The grain structure and composition remain rather similar in the two samples. The grain boundary phase averages ∼1 endash approx-gt 10 nm in width. The thicker grain boundaries are Nd-rich, while the thinner grain boundaries in the hot-pressed sample exhibit an Fe-rich composition near that of the NdFe 3 phase. Nd-rich phases are found at the grain boundary junctions of both samples, with the Nd:Fe ratio near 7:3 in the die-upset sample, and up to 3:2 in the hot-pressed sample. The significance of the microstructure and the grain boundary phases on the magnetic behavior in the two samples is discussed. copyright 1996 American Institute of Physics

  5. Selected physical, biological and biogeochemical implications of a rapidly changing Arctic Marginal Ice Zone

    Science.gov (United States)

    Barber, David G.; Hop, Haakon; Mundy, Christopher J.; Else, Brent; Dmitrenko, Igor A.; Tremblay, Jean-Eric; Ehn, Jens K.; Assmy, Philipp; Daase, Malin; Candlish, Lauren M.; Rysgaard, Søren

    2015-12-01

    The Marginal Ice Zone (MIZ) of the Arctic Ocean is changing rapidly due to a warming Arctic climate with commensurate reductions in sea ice extent and thickness. This Pan-Arctic review summarizes the main changes in the Arctic ocean-sea ice-atmosphere (OSA) interface, with implications for primary- and secondary producers in the ice and the underlying water column. Changes in the Arctic MIZ were interpreted for the period 1979-2010, based on best-fit regressions for each month. Trends of increasingly open water were statistically significant for each month, with quadratic fit for August-November, illustrating particularly strong seasonal feedbacks in sea-ice formation and decay. Geographic interpretations of physical and biological changes were based on comparison of regions with significant changes in sea ice: (1) The Pacific Sector of the Arctic Ocean including the Canada Basin and the Beaufort, Chukchi and East Siberian seas; (2) The Canadian Arctic Archipelago; (3) Baffin Bay and Hudson Bay; and (4) the Barents and Kara seas. Changes in ice conditions in the Barents sea/Kara sea region appear to be primarily forced by ocean heat fluxes during winter, whereas changes in the other sectors appear to be more summer-autumn related and primarily atmospherically forced. Effects of seasonal and regional changes in OSA-system with regard to increased open water were summarized for photosynthetically available radiation, nutrient delivery to the euphotic zone, primary production of ice algae and phytoplankton, ice-associated fauna and zooplankton, and gas exchange of CO2. Changes in the physical factors varied amongst regions, and showed direct effects on organisms linked to sea ice. Zooplankton species appear to be more flexible and likely able to adapt to variability in the onset of primary production. The major changes identified for the ice-associated ecosystem are with regard to production timing and abundance or biomass of ice flora and fauna, which are related to

  6. Specific changes in rapidly transported proteins during regeneration of the goldfish optic nerve

    International Nuclear Information System (INIS)

    Benowitz, L.I.; Shashoua, V.E.; Yoon, M.G.

    1981-01-01

    Double labeling methods were used to identify changes in the complement of proteins synthesized in the retinal ganglion cells and transported down the optic nerve during the process of axonal regeneration. Eight to 62 days after goldfish underwent a unilateral optic nerve crush, one eye was labeled with [3H]-, the other with [14C]proline. Control and regenerating optic nerves were dissected out and homogenized together after 5 hr, a time which allowed us to examine selectively membrane-bound components which migrate in the rapid phase of axoplasmic transport. Proteins from the two sides were so-purified and separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Analysis of the 3H and 14C incorporation patterns along the gels revealed a radical shift away from the normal labeling spectrum during regeneration, with selective changes in labeling at particular molecular weights varying over a 3-fold range. Eight days after crushing the optic nerve, the greatest increases in labeling were seen for material with apparent molecular weights of 24,000 to 27,000, 44,000, and 210,000 daltons. These peaks declined thereafter, and on days 29 to 39, the most prominent increases were at 110,000 to 140,000 daltons. These studies indicate a continuously changing pattern in the synthesis and/or degradation of proteins that are rapidly transported down the optic nerve during regeneration and point to molecular species potential significance in the establishment of the visual map upon the brain

  7. Modulators of mercury risk to wildlife and humans in the context of rapid global change

    Science.gov (United States)

    Eagles-Smith, Collin A.; Silbergeld, Ellen K.; Basu, Niladri; Bustamante, Paco; Diaz-Barriga, Fernando; Hopkins, William A.; Kidd, Karen A.; Nyland, Jennifer F.

    2018-01-01

    Environmental mercury (Hg) contamination is an urgent global health threat. The complexity of Hg in the environment can hinder accurate determination of ecological and human health risks, particularly within the context of the rapid global changes that are altering many ecological processes, socioeconomic patterns, and other factors like infectious disease incidence, which can affect Hg exposures and health outcomes. However, the success of global Hg-reduction efforts depends on accurate assessments of their effectiveness in reducing health risks. In this paper, we examine the role that key extrinsic and intrinsic drivers play on several aspects of Hg risk to humans and organisms in the environment. We do so within three key domains of ecological and human health risk. First, we examine how extrinsic global change drivers influence pathways of Hg bioaccumulation and biomagnification through food webs. Next, we describe how extrinsic socioeconomic drivers at a global scale, and intrinsic individual-level drivers, influence human Hg exposure. Finally, we address how the adverse health effects of Hg in humans and wildlife are modulated by a range of extrinsic and intrinsic drivers within the context of rapid global change. Incorporating components of these three domains into research and monitoring will facilitate a more holistic understanding of how ecological and societal drivers interact to influence Hg health risks.

  8. Facile and rapid one-pot microwave-assisted synthesis of Pd-Ni magnetic nanoalloys confined in mesoporous carbons

    International Nuclear Information System (INIS)

    Martínez de Yuso, Alicia; Le Meins, Jean-Marc; Oumellal, Yassine; Paul-Boncour, Valérie; Zlotea, Claudia; Matei Ghimbeu, Camelia

    2016-01-01

    An easy and rapid one-pot microwave-assisted soft-template synthesis method for the preparation of Pd-Ni nanoalloys confined in mesoporous carbon is reported. This approach allows the formation of mesoporous carbon and the growth of the particles at the same time, under short microwave irradiation (4 h) compared to the several days spent for the classical approach. In addition, the synthesis steps are diminished and no thermopolymerization step or reduction treatment being required. The influence of the Pd-Ni composition on the particle size and on the carbon characteristics was investigated. Pd-Ni solid solutions in the whole composition range could be obtained, and the metallic composition proved to have an important effect on the nanoparticle size but low influence on carbon textural properties. Small and uniformly distributed nanoparticles were confined in mesoporous carbon with uniform pore size distribution, and dependence between the nanoparticle size and the nanoalloy composition was observed, i.e., increase of the particle size with increasing the Ni content (from 5 to 14 nm). The magnetic properties of the materials showed a strong nanoparticle size and/or composition effect. The blocking temperature of Pd-Ni nanoalloys increases with the increase of Ni amount and therefore of particle size. The magnetization values are smaller than the bulk counterpart particularly for the Ni-rich compositions due to the formed graphitic shells surrounding the particles inducing a dead magnetic layer.

  9. Facile and rapid one-pot microwave-assisted synthesis of Pd-Ni magnetic nanoalloys confined in mesoporous carbons

    Science.gov (United States)

    Martínez de Yuso, Alicia; Le Meins, Jean-Marc; Oumellal, Yassine; Paul-Boncour, Valérie; Zlotea, Claudia; Matei Ghimbeu, Camelia

    2016-12-01

    An easy and rapid one-pot microwave-assisted soft-template synthesis method for the preparation of Pd-Ni nanoalloys confined in mesoporous carbon is reported. This approach allows the formation of mesoporous carbon and the growth of the particles at the same time, under short microwave irradiation (4 h) compared to the several days spent for the classical approach. In addition, the synthesis steps are diminished and no thermopolymerization step or reduction treatment being required. The influence of the Pd-Ni composition on the particle size and on the carbon characteristics was investigated. Pd-Ni solid solutions in the whole composition range could be obtained, and the metallic composition proved to have an important effect on the nanoparticle size but low influence on carbon textural properties. Small and uniformly distributed nanoparticles were confined in mesoporous carbon with uniform pore size distribution, and dependence between the nanoparticle size and the nanoalloy composition was observed, i.e., increase of the particle size with increasing the Ni content (from 5 to 14 nm). The magnetic properties of the materials showed a strong nanoparticle size and/or composition effect. The blocking temperature of Pd-Ni nanoalloys increases with the increase of Ni amount and therefore of particle size. The magnetization values are smaller than the bulk counterpart particularly for the Ni-rich compositions due to the formed graphitic shells surrounding the particles inducing a dead magnetic layer.

  10. Facile and rapid one-pot microwave-assisted synthesis of Pd-Ni magnetic nanoalloys confined in mesoporous carbons

    Energy Technology Data Exchange (ETDEWEB)

    Martínez de Yuso, Alicia; Le Meins, Jean-Marc [Université de Strasbourg, Université de Haute-Alsace, Institut de Science des Matériaux de Mulhouse, CNRS UMR (France); Oumellal, Yassine; Paul-Boncour, Valérie; Zlotea, Claudia [Institut de Chimie et des Matériaux Paris Est, UMR 7182, CNRS-UPEC (France); Matei Ghimbeu, Camelia, E-mail: camelia.ghimbeu@uha.fr [Université de Strasbourg, Université de Haute-Alsace, Institut de Science des Matériaux de Mulhouse, CNRS UMR (France)

    2016-12-15

    An easy and rapid one-pot microwave-assisted soft-template synthesis method for the preparation of Pd-Ni nanoalloys confined in mesoporous carbon is reported. This approach allows the formation of mesoporous carbon and the growth of the particles at the same time, under short microwave irradiation (4 h) compared to the several days spent for the classical approach. In addition, the synthesis steps are diminished and no thermopolymerization step or reduction treatment being required. The influence of the Pd-Ni composition on the particle size and on the carbon characteristics was investigated. Pd-Ni solid solutions in the whole composition range could be obtained, and the metallic composition proved to have an important effect on the nanoparticle size but low influence on carbon textural properties. Small and uniformly distributed nanoparticles were confined in mesoporous carbon with uniform pore size distribution, and dependence between the nanoparticle size and the nanoalloy composition was observed, i.e., increase of the particle size with increasing the Ni content (from 5 to 14 nm). The magnetic properties of the materials showed a strong nanoparticle size and/or composition effect. The blocking temperature of Pd-Ni nanoalloys increases with the increase of Ni amount and therefore of particle size. The magnetization values are smaller than the bulk counterpart particularly for the Ni-rich compositions due to the formed graphitic shells surrounding the particles inducing a dead magnetic layer.

  11. Neurogenomics and the role of a large mutational target on rapid behavioral change.

    Science.gov (United States)

    Stanley, Craig E; Kulathinal, Rob J

    2016-11-08

    Behavior, while complex and dynamic, is among the most diverse, derived, and rapidly evolving traits in animals. The highly labile nature of heritable behavioral change is observed in such evolutionary phenomena as the emergence of converged behaviors in domesticated animals, the rapid evolution of preferences, and the routine development of ethological isolation between diverging populations and species. In fact, it is believed that nervous system development and its potential to evolve a seemingly infinite array of behavioral innovations played a major role in the successful diversification of metazoans, including our own human lineage. However, unlike other rapidly evolving functional systems such as sperm-egg interactions and immune defense, the genetic basis of rapid behavioral change remains elusive. Here we propose that the rapid divergence and widespread novelty of innate and adaptive behavior is primarily a function of its genomic architecture. Specifically, we hypothesize that the broad diversity of behavioral phenotypes present at micro- and macroevolutionary scales is promoted by a disproportionately large mutational target of neurogenic genes. We present evidence that these large neuro-behavioral targets are significant and ubiquitous in animal genomes and suggest that behavior's novelty and rapid emergence are driven by a number of factors including more selection on a larger pool of variants, a greater role of phenotypic plasticity, and/or unique molecular features present in large genes. We briefly discuss the origins of these large neurogenic genes, as they relate to the remarkable diversity of metazoan behaviors, and highlight key consequences on both behavioral traits and neurogenic disease across, respectively, evolutionary and ontogenetic time scales. Current approaches to studying the genetic mechanisms underlying rapid phenotypic change primarily focus on identifying signatures of Darwinian selection in protein-coding regions. In contrast

  12. Experiences of Families Transmitting Values in a Rapidly Changing Society: Implications for Family Therapists.

    Science.gov (United States)

    Akyil, Yudum; Prouty, Anne; Blanchard, Amy; Lyness, Kevin

    2016-06-01

    Intergenerational value transmission affects parent-child relationships and necessitates constant negotiation in families. Families with adolescents from rapidly changing societies face unique challenges in balancing the traditional collectivistic family values that promote harmony with emerging values that promote autonomy. Using modern Turkey as an example of such a culture, the authors examine the transmission process in families that hold more traditional and collectivistic values than their adolescent children. Special consideration is given to generational and cultural differences in the autonomy and relatedness dimensions. © 2015 Family Process Institute.

  13. Wiki management a revolutionary new model for a rapidly changing and collaborative world

    CERN Document Server

    Collins, Rod

    2013-01-01

    We now live in a "wiki" world where mass collaboration is not only possible-it's often the best solution. Conventional management thought assumes that command-and-control is the most effective way to organize the efforts of large numbers of people, but rapid change and increasing complexity have rendered that model obsolete. As a result, most managers today lack the skills and knowledge needed to succeed in an age when networks are proving smarter and faster than hierarchies. Designing organizations for mass collaboration demands a new and very different model-wiki management.

  14. Tropical vegetation evidence for rapid sea level changes associated with Heinrich Events

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, Catalina; Dupont, Lydie M, E-mail: catalina@uni-bremen.d, E-mail: dupont@uni-bremen.d [MARUM - Centre for Marine Environmental Sciences, University of Bremen, Leobener Strasse, D-28359 Germany (Germany)

    2010-03-15

    A Cariaco Basin pollen record shows the development of tropical salt marshes during marine isotope stage 3. Rapid and abrupt expansions of salt marsh vegetation in tropical South America are associated with north Atlantic Heinrich Events stadials (HE-stadials). Intervals of salt marsh expansion have an internal structure, which consists of a recurrent alternation of species that starts with pollen increments of Chenopodiaceae, that are followed by increments of grasses, and subsequently by increments of Cyperaceae. This pattern suggests a successional process that is determined by the close relationship between sea-level and plant community dynamics. The salt tolerant Chenopodiaceae, indicate hypersaline intertidal environments, which were most likely promoted by extremely dry atmospheric conditions. Rapid sea-level rise characterizes the onset of HE-stadials, causing the continued recruitment of pioneer species, which are the only ones tolerating rapid rates of disturbance. Once sea-level rise decelerates, marsh plants are able to trap and stabilize sediments, favouring the establishment of more competitive species. These results add to the scarce knowledge on the dynamics of tropical salt marsh ecosystems, and provide independent paleoclimatic evidence on sea-level changes following Antarctic climate variability.

  15. Rapid gene expression changes in peripheral blood lymphocytes upon practice of a comprehensive yoga program.

    Directory of Open Access Journals (Sweden)

    Su Qu

    Full Text Available One of the most common integrative medicine (IM modalities is yoga and related practices. Previous work has shown that yoga may improve wellness in healthy people and have benefits for patients. However, the mechanisms of how yoga may positively affect the mind-body system are largely unknown. Here we have assessed possible rapid changes in global gene expression profiles in the peripheral blood mononuclear cells (PBMCs in healthy people that practiced either a comprehensive yoga program or a control regimen. The experimental sessions included gentle yoga postures, breathing exercises, and meditation (Sudarshan Kriya and Related Practices--SK&P compared with a control regimen of a nature walk and listening to relaxing music. We show that the SK&P program has a rapid and significantly greater effect on gene expression in PBMCs compared with the control regimen. These data suggest that yoga and related practices result in rapid gene expression alterations which may be the basis for their longer term cell biological and higher level health effects.

  16. Development of a System for Rapid Detection of Contaminants in Water Supplies Using Magnetic Resonance and Nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Lowery, Thomas J; Neely, Lori; Chepin, James; Wellman, Parris; Toso, Ken; Murray, Paul; Audeh, Mark; Demas, Vasiliki; Palazzolo, Robert; Min, Michael; Phung, Nu; Blanco, Matt; Raphel, Jordan; O' Neil, Troy

    2010-09-14

    To keep the water supply safe and to ensure a swift and accurate response to a water supply contamination event, rapid and robust methods for microbial testing are necessary. Current technologies are complex, lengthy and costly and there is a need for rapid, reliable, and precise approaches that can readily address this fundamental security and safety issue. T2 Biosystems is focused on providing solutions to this problem by making breakthroughs in nanotechnology and biosensor techniques that address the current technical restrictions facing rapid, molecular analysis in complex samples. In order to apply the T2 Biosystems nucleic acid detection procedure to the analysis of nucleic acid targets in unprocessed water samples, Bacillus thuringeinsis was selected as a model organism and local river water was selected as the sample matrix. The initial assay reagent formulation was conceived with a manual magnetic resonance reader, was optimized using a high throughput system, and transferred back to the MR reader for potential field use. The final assay employing the designed and manufactured instruments was capable of detecting 10 CFU/mL of B. thuringiensis directly within the environmental water sample within 90 minutes. Further, discrimination of two closely related species of Bacilli was accomplished using the methods of this project; greater than 3-fold discrimination between B. cereus and B. thuringiensis at a concentrations spanning 10 CFU/mL to 10{sup 5} CFU/mL was observed.

  17. Magnetic Inflation and Stellar Mass. II. On the Radii of Single, Rapidly Rotating, Fully Convective M-Dwarf Stars

    Science.gov (United States)

    Kesseli, Aurora Y.; Muirhead, Philip S.; Mann, Andrew W.; Mace, Greg

    2018-06-01

    Main-sequence, fully convective M dwarfs in eclipsing binaries are observed to be larger than stellar evolutionary models predict by as much as 10%–15%. A proposed explanation for this discrepancy involves effects from strong magnetic fields, induced by rapid rotation via the dynamo process. Although, a handful of single, slowly rotating M dwarfs with radius measurements from interferometry also appear to be larger than models predict, suggesting that rotation or binarity specifically may not be the sole cause of the discrepancy. We test whether single, rapidly rotating, fully convective stars are also larger than expected by measuring their R\\sin i distribution. We combine photometric rotation periods from the literature with rotational broadening (v\\sin i) measurements reported in this work for a sample of 88 rapidly rotating M dwarf stars. Using a Bayesian framework, we find that stellar evolutionary models underestimate the radii by 10 % {--}15{ % }-2.5+3, but that at higher masses (0.18 theory is 13%–18%, and we argue that the discrepancy is unlikely to be due to effects from age. Furthermore, we find no statistically significant radius discrepancy between our sample and the handful of M dwarfs with interferometric radii. We conclude that neither rotation nor binarity are responsible for the inflated radii of fully convective M dwarfs, and that all fully convective M dwarfs are larger than models predict.

  18. Rapid changes in protein phosphorylation associated with gravity perception in corn roots

    International Nuclear Information System (INIS)

    McFadden, J.J.; Poovaiah, B.W.

    1987-01-01

    A previous paper from this laboratory showed calcium- and calmodulin-dependent in vivo protein phosphorylation in corn root tips. The authors show that rapid changes in calcium-dependent protein phosphorylation are involved in light-dependent graviperception in corn root tips. Corn seedlings (Zea mays L, cv Merit) were grown in the dark for 3 d, then apical root segments were harvested in dim green light to measure in vivo protein phosphorylation. Segments were incubated with 0.5 mCi 32 P for 1 h, then immediately frozen in liquid N 2 or first treated with either 7 min light, or 7 min light plus 1 mM EGTA and 10 μM A23187. Labeled proteins were separated by 2D gel electrophoresis and detected by autoradiography. Light caused rapid and specific promotion of phosphorylation of 5 polypeptides. The increases in protein phosphorylation were reversed by treating with EGTA and A23187. The authors postulate that these changes in protein phosphorylation are an essential part of the light-dependent gravity response in Merit roots

  19. Health Systems Research in a Complex and Rapidly Changing Context: Ethical Implications of Major Health Systems Change at Scale.

    Science.gov (United States)

    MacGregor, Hayley; Bloom, Gerald

    2016-12-01

    This paper discusses health policy and systems research in complex and rapidly changing contexts. It focuses on ethical issues at stake for researchers working with government policy makers to provide evidence to inform major health systems change at scale, particularly when the dynamic nature of the context and ongoing challenges to the health system can result in unpredictable outcomes. We focus on situations where 'country ownership' of HSR is relatively well established and where there is significant involvement of local researchers and close ties and relationships with policy makers are often present. We frame our discussion around two country case studies with which we are familiar, namely China and South Africa and discuss the implications for conducting 'embedded' research. We suggest that reflexivity is an important concept for health system researchers who need to think carefully about positionality and their normative stance and to use such reflection to ensure that they can negotiate to retain autonomy, whilst also contributing evidence for health system change. A research process informed by the notion of reflexive practice and iterative learning will require a longitudinal review at key points in the research timeline. Such review should include the convening of a deliberative process and should involve a range of stakeholders, including those most likely to be affected by the intended and unintended consequences of change. © 2016 The Authors Developing World Bioethics Published by John Wiley & Sons Ltd.

  20. Cerebral magnetic resonance changes associated with fibromyalgia syndrome.

    Science.gov (United States)

    Murga, Iñigo; Guillen, Virginia; Lafuente, José-Vicente

    2017-06-07

    Fibromyalgia syndrome is a chronic disease, of unknown origin, whose diagnostic criteria were established in 1990 by the American College of Rheumatology. New criteria were proposed in 2010 that have not yet been validated. It is characterized by a generalized chronic musculoskeletal pain, accompanied by hyperalgesia and allodynia, as well as other motor, vegetative, cognitive and affective symptoms and signs. We have reviewed a set of studies with cerebral magnetic resonance (morphometry, connectivity and spectroscopy) that refer to changes in areas involved in pain processing. Modifications in gray and white matter volume, as well as in levels of N-acetylaspartate, choline or glutamate, among other metabolites, have been observed in the hippocampus, insula, prefrontal and cingular cortex. Neuroradiological findings are nonspecific and similar to those found in other examples of chronic pain. An increase in the sample size and a standardized methodology would facilitate comparison, allowing the drawing of general conclusions. Copyright © 2017 Elsevier España, S.L.U. All rights reserved.

  1. Rapid and quantitative chemical exchange saturation transfer (CEST) imaging with magnetic resonance fingerprinting (MRF).

    Science.gov (United States)

    Cohen, Ouri; Huang, Shuning; McMahon, Michael T; Rosen, Matthew S; Farrar, Christian T

    2018-05-13

    To develop a fast magnetic resonance fingerprinting (MRF) method for quantitative chemical exchange saturation transfer (CEST) imaging. We implemented a CEST-MRF method to quantify the chemical exchange rate and volume fraction of the N α -amine protons of L-arginine (L-Arg) phantoms and the amide and semi-solid exchangeable protons of in vivo rat brain tissue. L-Arg phantoms were made with different concentrations (25-100 mM) and pH (pH 4-6). The MRF acquisition schedule varied the saturation power randomly for 30 iterations (phantom: 0-6 μT; in vivo: 0-4 μT) with a total acquisition time of ≤2 min. The signal trajectories were pattern-matched to a large dictionary of signal trajectories simulated using the Bloch-McConnell equations for different combinations of exchange rate, exchangeable proton volume fraction, and water T 1 and T 2 relaxation times. The chemical exchange rates of the N α -amine protons of L-Arg were significantly (P exchange using saturation power method. Similarly, the L-Arg concentrations determined using MRF were significantly (P exchange rate was well fit (R 2  = 0.9186) by a base catalyzed exchange model. The amide proton exchange rate measured in rat brain cortex (34.8 ± 11.7 Hz) was in good agreement with that measured previously with the water exchange spectroscopy method (28.6 ± 7.4 Hz). The semi-solid proton volume fraction was elevated in white (12.2 ± 1.7%) compared to gray (8.1 ± 1.1%) matter brain regions in agreement with previous magnetization transfer studies. CEST-MRF provides a method for fast, quantitative CEST imaging. © 2018 International Society for Magnetic Resonance in Medicine.

  2. Pattern of magnetic resonance imaging and magnetic resonance venography changes in cerebral venous sinus thrombosis

    International Nuclear Information System (INIS)

    Zafar, A.; Ali, Z.

    2012-01-01

    Background: Cerebral venous sinus thrombosis is a common but highly under-recognised condition, which is missed not only by general practitioners but also by neurologists. Computerised tomography (CT) or magnetic resonance imaging (MRI) of brain alone is not sufficient to diagnose this condition. Objective of this study was to explore the pattern of magnetic resonance imaging (MRI) and magnetic resonance venography (MRV) changes in cerebral venous sinus thrombosis (CVST). Methods: This was a descriptive study in which 52 cases of cerebral venous sinus thrombosis with special emphasis on their MRI and MRV findings were included. The study was conducted in Neurology Unit, Lady Reading Hospital, Peshawar, Pakistan, from January 2010 to July 2011. All patients suffering from cerebral venous sinus thrombosis were included in the study. Multi-planar/multi-sequential, Tesla 1.5 MRI/MRV time of flight images were done in all cases where there was suspicion of cerebral venous sinus thrombosis. Results: Out of 52 patients with cerebral venous sinus thrombosis 41 (78.84%) were female and 11 (21.15%) were male. Mean age was 37+-5 years. Definite risk factors were found in 38 (73.076%) patients with pregnancy, use of oral contraceptives or puerperium being the most frequently found risk factor in 20 (73.076%) patients. Most common complaint was headache found in 41 (78.84%) patients, followed by focal neurological deficits, and altered mental status and seizures. Papilloedema was seen in 20 (38.46%) patients. The cerebral venous sinuses most frequently involved were transverse and sigmoid sinuses in 17 patients (32.69%) while superior sagittal sinus alone in 10 (19.23%) patients. Overall CT brain was normal in 30% and MRI brain in 23.07% patients; however, MRV of these patients revealed CVST. Conclusion: Imaging plays a primary role in the diagnosis of cerebral venous sinus thrombosis because the clinical picture of CVST is non-specific and highly variable. Thrombosis of

  3. Changes in Patient and Nurse Outcomes Associated with Magnet Hospital Recognition

    Science.gov (United States)

    Kutney-Lee, Ann; Stimpfel, Amy Witkoski; Sloane, Douglas M.; Cimiotti, Jeannie P.; Quinn, Lisa W.; Aiken, Linda H.

    2015-01-01

    Background Research has documented an association between Magnet hospitals and better outcomes for nurses and patients. However, little longitudinal evidence exists to support a causal link between Magnet recognition and outcomes. Objective To compare changes over time in surgical patient outcomes, nurse-reported quality, and nurse outcomes in a sample of hospitals that attained Magnet recognition between 1999 and 2007 with hospitals that remained non-Magnet. Research Design Retrospective, two-stage panel design using four secondary data sources. Subjects 136 Pennsylvania hospitals (11 “emerging” Magnets and 125 non-Magnets) Measures American Nurses Credentialing Center Magnet recognition; risk-adjusted rates of surgical 30-day mortality and failure-to-rescue, nurse-reported quality measures, and nurse outcomes; the Practice Environment Scale of the Nursing Work Index Methods Fixed effects difference models were used to compare changes in outcomes between emerging Magnet hospitals and hospitals that remained non-Magnet. Results Emerging Magnet hospitals demonstrated markedly greater improvements in their work environments than other hospitals. On average, the changes in 30-day surgical mortality and failure-to-rescue rates over the study period were more pronounced in emerging Magnet hospitals than in non-Magnet hospitals, by 2.4 fewer deaths per 1000 patients (pMagnet hospitals and non-Magnet hospitals were observed in nurse-reported quality of care and nurse outcomes. Conclusions In general, Magnet recognition is associated with significant improvements over time in the quality of the work environment, and in patient and nurse outcomes that exceed those of non-Magnet hospitals. PMID:25906016

  4. Developmental changes in magnetic resonance imaging of the brain in children

    International Nuclear Information System (INIS)

    Aihara, Masao; Iai, Mizue; Takeuchi, Akio; Tamai, Kazuto; Tanabe, Yuzo; Nakajima, Hironori

    1986-01-01

    Nine normal subjects (aged 3 months to 15 years) were exmined by a Picker Vista magnetic resonance (MR) imager with a 0.5 T superconducting magnet operated at 0.256 T. Inversion-recovery images showed a high intensity in the posterior limb of the internal capsule and thalami and occipital radiation, and a low intensity in the frontal region in an infant aged 3 months. In an infant aged 8 months, high intensity areas were seen in the anterior limb of the internal capsule and in the corpus callosum. In a child aged 1 year, there were extensive high intensities in the subcortical white matter. At the age of 8, this became more extensive. A consistent decrease in the T1 values in all regions was observed with age. The T1 values decreased rapidly from 3 to 8 months, and then remained relatively constant in the second decade of life. There was a difference in T1 values between the frontal and occipital white matter in the first year of life. For a 3-month-old infant, the T1 value was 650 msec in the posterior limb of the internal capsule. The T1 value decreased rapidly in infants below 1 year and reached the constant level (300 to 350 msec) in the second decade of life. The central somatosensory conduction time decreased gradually from 3 to 8 months after birth. We suppose that the developmental changes in MR imaging and T1 values are correlated with those of the water and lipid contents and the myelination cycles of the brain. (J.P.N.)

  5. Rapid heating effects on grain-size, texture and magnetic properties ...

    Indian Academy of Sciences (India)

    Administrator

    oriented electrical steels (Kumar et ... through changes in recovery and recrystallization beha- viour during the final annealing treatment (Duan et .... recovery, recrystallization and grain coarsening (Doherty et al 1988). The size of recrystallized grain is ...

  6. Magnetic resonance imaging features of fibrocystic change of the breast.

    Science.gov (United States)

    Chen, Jeon-Hor; Liu, Hui; Baek, Hyeon-Man; Nalcioglu, Orhan; Su, Min-Ying

    2008-11-01

    Studies specifically reporting MRI of fibrocystic change (FCC) of the breast are very few and its MRI features are not clearly known. The purpose of this study was to analyze the MRI features of FCC of the breast. Thirty-one patients with pathologically proven FCC of the breast were retrospectively reviewed. The MRI study was performed using a 1.5-T MR scanner with standard bilateral breast coil. The imaging protocol consisted of pre-contrast T1-weighed imaging and dynamic contrast-enhanced axial T1-weighed imaging. The MRI features were interpreted based on the morphologic and enhancement kinetic descriptors defined on ACR BIRADS-MRI lexicon. FCC of the breast had a wide spectrum of morphologic and kinetic features on MRI. Two types of FCC were found, including a more diffuse type of nonmass lesion (12/31, 39%) showing benign enhancement kinetic pattern with medium wash-in in early phase (9/10, 90%) and a focal mass-type lesion (11/31, 35%) with enhancement kinetic usually showing rapid up-slope mimicking a breast cancer (8/11, 73%). MRI is able to elaborate the diverse imaging features of FCC of the breast. Our result showed that FCC presenting as a focal mass-type lesion was usually overdiagnosed as malignancy. Understanding MRI of FCC is important to determine which cohort of patients should be followed up alone or receive aggressive management.

  7. Coercivity enhancement of HDDR-processed Nd-Fe-B permanent magnet with the rapid hot-press consolidation process

    Energy Technology Data Exchange (ETDEWEB)

    Nozawa, N. [Magnetic Materials Research Laboratory, NEOMAX Company, Hitachi Metals Ltd., Osaka 618-0013 (Japan); Sepehri-Amin, H. [Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba 305-8571 (Japan); Magnetic Materials Center, National Institute for Materials Science, Tsukuba 305-0047 (Japan); Ohkubo, T. [Magnetic Materials Center, National Institute for Materials Science, Tsukuba 305-0047 (Japan); Hono, K. [Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba 305-8571 (Japan); Magnetic Materials Center, National Institute for Materials Science, Tsukuba 305-0047 (Japan); Nishiuchi, T. [Magnetic Materials Research Laboratory, NEOMAX Company, Hitachi Metals Ltd., Osaka 618-0013 (Japan); Hirosawa, S., E-mail: Satoshi_Hirosawa@hitachi-metals.co.j [Magnetic Materials Research Laboratory, NEOMAX Company, Hitachi Metals Ltd., Osaka 618-0013 (Japan)

    2011-01-15

    High coercivity, fully dense anisotropic permanent magnets of submicron grain sizes were produced by rapid hot-press consolidation of hydrogenation-disproportionation-desorption-recombination (HDDR) processed Nd-Fe-Co-B powders. In the hot-press process, the coercivity of the consolidated material showed a sharp minimum prior to full densification. Thereafter, it reached a value 25% higher than that of the initial powder. Scanning electron microscopy and transmission electron microscopy observations revealed that the variation in H{sub cJ} was caused by a redistribution of Nd along the grain boundaries during hot pressing and that the high coercivity was attributable to the formation of thin, continuous Nd-rich phase along the grain boundaries.

  8. Rapidly Assessing Changes in Bone Mineral Balance Using Natural Stable Calcium Isotopes

    Science.gov (United States)

    Morgan, J. L. L.; Gordon, G. W.; Romaniello, S. J.; Skulan, J. L.; Smith, S. M.; Anbar, A. D.

    2011-01-01

    We demonstrate that variations in the Ca isotope ratios in urine rapidly and quantitatively reflect changes in bone mineral balance. This variation occurs because bone formation depletes soft tissue of light Ca isotopes, while bone resorption releases that isotopically light Ca back into soft tissue. In a study of 12 individuals confined to bed rest, a condition known to induce bone resorption, we show that Ca isotope ratios shift in a direction consistent with net bone loss after just 7 days, long before detectible changes in bone density occur. Consistent with this interpretation, the Ca isotope variations track changes observed in N-teleopeptide, a bone resorption biomarker, while bone-specific alkaline phosphatase, a bone formation biomarker, is unchanged. Ca isotopes can in principle be used to quantify net changes in bone mass. Ca isotopes indicate an average loss of 0.62 +/- 0.16 % in bone mass over the course of this 30-day study. The Ca isotope technique should accelerate the pace of discovery of new treatments for bone disease and provide novel insights into the dynamics of bone metabolism.

  9. Wildlife health in a rapidly changing North: focus on avian disease

    Science.gov (United States)

    Van Hemert, Caroline R.; Pearce, John M.; Handel, Colleen M.

    2014-01-01

    Climate-related environmental changes have increasingly been linked to emerging infectious diseases in wildlife. The Arctic is facing a major ecological transition that is expected to substantially affect animal and human health. Changes in phenology or environmental conditions that result from climate warming may promote novel species assemblages as host and pathogen ranges expand to previously unoccupied areas. Recent evidence from the Arctic and subarctic suggests an increase in the spread and prevalence of some wildlife diseases, but baseline data necessary to detect and verify such changes are still lacking. Wild birds are undergoing rapid shifts in distribution and have been implicated in the spread of wildlife and zoonotic diseases. Here, we review evidence of current and projected changes in the abundance and distribution of avian diseases and outline strategies for future research. We discuss relevant climatic and environmental factors, emerging host–pathogen contact zones, the relationship between host condition and immune function, and potential wildlife and human health outcomes in northern regions.

  10. Monitoring Forest Change in Landscapes Under-Going Rapid Energy Development: Challenges and New Perspectives

    Directory of Open Access Journals (Sweden)

    Paul D. Pickell

    2014-07-01

    Full Text Available The accelerated development of energy resources around the world has substantially increased forest change related to oil and gas activities. In some cases, oil and gas activities are the primary catalyst of land-use change in forested landscapes. We discuss the challenges associated with characterizing ecological change related to energy resource development using North America as an exemplar. We synthesize the major impacts of energy development to forested ecosystems and offer new perspectives on how to detect and monitor anthropogenic disturbance during the Anthropocene. The disturbance of North American forests for energy development has resulted in persistent linear corridors, suppression of historical disturbance regimes, novel ecosystems, and the eradication of ecological memory. Characterizing anthropogenic disturbances using conventional patch-based disturbance measures will tend to underestimate the ecological impacts of energy development. Suitable indicators of anthropogenic impacts in forests should be derived from the integration of multi-scalar Earth observations. Relating these indicators to ecosystem condition will be a capstone in the progress toward monitoring forest change in landscapes undergoing rapid energy development.

  11. Rapid landscape change in 6th century northern Jordan: interdisciplinary geoarchaeological perspectives

    Science.gov (United States)

    Lucke, Bernhard

    2016-04-01

    Landscapes of the ancient fertile crescent are considered affected by soil degradation as result of long-term farming since the Neolithic, and impressive ruins of antiquity led to assumptions that their abandonment must have been conntected with reduced agricultural productivity. In this context, a valley fill near the site of Abila of the Decapolis in northern Jordan was apparently deposited largely during the 6th century AD, and provides evidence for a rapid and intense landscape change during the Late Byzantine period. However, an interdisciplinary case study of land use, soil development, and sediments found that the valley fill cannot be connected with large-scale soil erosion in the vicinity of the site. On the one hand, this is indicated by the distribution of soil development and archaeological material as marker of past land use activity in the past, which suggests that the best soils were and still are used intensively. On the other hand, the sediments seem to point to the occurrence of climatic extremes such as heavy floods, the occurrence of soil creep after water saturation, but also a significant shift to aridity which may have triggered socio-economic changes of subsistence strategies from agriculture to pastoralism. The dates of sediments which are available so far indicate that the climatic change seemingly occurred rapidly within approximately 100 years during the late 6th and early 7th century AD, possibly connected with the "year without sun" or 'Mystery Veil' which the Byzantine historian Procopius described in the year 536 AD. Modern analogies of the Pinatubo eruption in 1991 let it seem possible that a volcanic event, perhaps the outbreak of the Ilopango volcano, was connected with these environmental turbulences. Such events cannot be understood by isolated studies: without a broad interdisciplinary framework, single archives are prone to misinterpretation, and our understanding of the environmental history of Abila is still very limited.

  12. Measuring Land Change in Coastal Zone around a Rapidly Urbanized Bay.

    Science.gov (United States)

    Huang, Faming; Huang, Boqiang; Huang, Jinliang; Li, Shenghui

    2018-05-23

    Urban development is a major cause for eco-degradation in many coastal regions. Understanding urbanization dynamics and underlying driving factors is crucial for urban planning and management. Land-use dynamic degree indices and intensity analysis were used to measure land changes occurred in 1990, 2002, 2009, and 2017 in the coastal zone around Quanzhou bay, which is a rapidly urbanized bay in Southeast China. The comprehensive land-use dynamic degree and interval level intensity analysis both revealed that land change was accelerating across the three time intervals in a three-kilometer-wide zone along the coastal line (zone A), while land change was fastest during the second time interval 2002⁻2009 in a separate terrestrial area within coastal zone (zone B). Driven by urbanization, built-up gains and cropland losses were active for all time intervals in both zones. Mudflat losses were active except in the first time interval in zone A due to the intensive sea reclamation. The gain of mangrove was active while the loss of mangrove is dormant for all three intervals in zone A. Transition level analysis further revealed the similarities and differences in processes within patterns of land changes for both zones. The transition from cropland to built-up was systematically targeted and stationary while the transition from woodland to built-up was systematically avoiding transition in both zones. Built-up tended to target aquaculture for the second and third time intervals in zone A but avoid Aquaculture for all intervals in zone B. Land change in zone A was more significant than that in zone B during the second and third time intervals at three-level intensity. The application of intensity analysis can enhance our understanding of the patterns and processes in land changes and suitable land development plans in the Quanzhou bay area. This type of investigation is useful to provide information for developing sound land use policy to achieve urban sustainability in

  13. Rapid Land Cover Map Updates Using Change Detection and Robust Random Forest Classifiers

    Directory of Open Access Journals (Sweden)

    Konrad J. Wessels

    2016-10-01

    Full Text Available The paper evaluated the Landsat Automated Land Cover Update Mapping (LALCUM system designed to rapidly update a land cover map to a desired nominal year using a pre-existing reference land cover map. The system uses the Iteratively Reweighted Multivariate Alteration Detection (IRMAD to identify areas of change and no change. The system then automatically generates large amounts of training samples (n > 1 million in the no-change areas as input to an optimized Random Forest classifier. Experiments were conducted in the KwaZulu-Natal Province of South Africa using a reference land cover map from 2008, a change mask between 2008 and 2011 and Landsat ETM+ data for 2011. The entire system took 9.5 h to process. We expected that the use of the change mask would improve classification accuracy by reducing the number of mislabeled training data caused by land cover change between 2008 and 2011. However, this was not the case due to exceptional robustness of Random Forest classifier to mislabeled training samples. The system achieved an overall accuracy of 65%–67% using 22 detailed classes and 72%–74% using 12 aggregated national classes. “Water”, “Plantations”, “Plantations—clearfelled”, “Orchards—trees”, “Sugarcane”, “Built-up/dense settlement”, “Cultivation—Irrigated” and “Forest (indigenous” had user’s accuracies above 70%. Other detailed classes (e.g., “Low density settlements”, “Mines and Quarries”, and “Cultivation, subsistence, drylands” which are required for operational, provincial-scale land use planning and are usually mapped using manual image interpretation, could not be mapped using Landsat spectral data alone. However, the system was able to map the 12 national classes, at a sufficiently high level of accuracy for national scale land cover monitoring. This update approach and the highly automated, scalable LALCUM system can improve the efficiency and update rate of regional land

  14. A rapid method for detection of genetically modified organisms based on magnetic separation and surface-enhanced Raman scattering.

    Science.gov (United States)

    Guven, Burcu; Boyacı, İsmail Hakkı; Tamer, Ugur; Çalık, Pınar

    2012-01-07

    In this study, a new method combining magnetic separation (MS) and surface-enhanced Raman scattering (SERS) was developed to detect genetically modified organisms (GMOs). An oligonucleotide probe which is specific for 35 S DNA target was immobilized onto gold coated magnetic nanospheres to form oligonucleotide-coated nanoparticles. A self assembled monolayer was formed on gold nanorods using 5,5'-dithiobis (2-nitrobenzoic acid) (DTNB) and the second probe of the 35 S DNA target was immobilized on the activated nanorod surfaces. Probes on the nanoparticles were hybridized with the target oligonucleotide. Optimization parameters for hybridization were investigated by high performance liquid chromatography. Optimum hybridization parameters were determined as: 4 μM probe concentration, 20 min immobilization time, 30 min hybridization time, 55 °C hybridization temperature, 750 mM buffer salt concentration and pH: 7.4. Quantification of the target concentration was performed via SERS spectra of DTNB on the nanorods. The correlation between the target concentration and the SERS signal was found to be linear within the range of 25-100 nM. The analyses were performed with only one hybridization step in 40 min. Real sample analysis was conducted using Bt-176 maize sample. The results showed that the developed MS-SERS assay is capable of detecting GMOs in a rapid and selective manner. This journal is © The Royal Society of Chemistry 2012

  15. Rapid determination of recent cocaine use with magnetic particles-based enzyme immunoassays in serum, saliva, and urine fluids.

    Science.gov (United States)

    Vidal, Juan C; Bertolín, Juan R; Bonel, Laura; Asturias, Laura; Arcos-Martínez, M Julia; Castillo, Juan R

    2016-06-05

    Cocaine is one of the most worldwide used illicit drugs. We report a magnetic particles-based enzyme-linked immunoassay (mpEIA) method for the rapid and sensitive determination of cocaine (COC) in saliva, urine and serum samples. Under optimized conditions, the limits of detections were 0.09ngmL(-1) (urine), 0.15ngmL(-1) (saliva), and 0.06ngmL(-1) COC (human serum). Sensitivities were in the range EC50=0.6-2.5ngmL(-1) COC. The cross-reactivity with the principal metabolite benzoylecgonine (BZE) was only 1.6%. Recovering percentages of doped samples (0, 10, 50, and 100ngmL(-1) of COC) ranged from about 86-111%. Some advantages of the developed mpEIA over conventional ELISA kits are faster incubations, improved reproducibility, and consumption of lower amounts of antibody and enzyme conjugates due to the use of magnetic beads. The reported method was validated following the guidelines on bioanalytical methods of the European Medicines Agency (2011). Unmetabolized COC detection has a great interest in pharmacological, pharmacokinetics, and toxicokinetics studies, and can be used to detect a very recent COC use (1-6h). Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Vector magnetic field changes associated with X-class flares

    Science.gov (United States)

    Wang, Haimin; Ewell, M. W., Jr.; Zirin, H.; Ai, Guoxiang

    1994-01-01

    We present high-resolution transverse and longitudinal magnetic field measurements bracketing five X-class solar flares. We show that the magnetic shear, defined as the angular difference between the measured field and calculated potential field, actually increases after all of these flares. In each case, the shear is shown to increase along a substantial portion of the magnetic neutral line. For two of the cases, we have excellent time resolution, on the order of several minutes, and we demonstrate that the shear increase is impulsive. We briefly discuss the theoretical implications of our results.

  17. Multiplex Biosensing Based on Highly Sensitive Magnetic Nanolabel Quantification: Rapid Detection of Botulinum Neurotoxins A, B, and E in Liquids.

    Science.gov (United States)

    Orlov, Alexey V; Znoyko, Sergey L; Cherkasov, Vladimir R; Nikitin, Maxim P; Nikitin, Petr I

    2016-11-01

    We present a multiplex quantitative lateral flow (LF) assay for simultaneous on-site detection of botulinum neurotoxin (BoNT) types A, B, and E in complex matrixes, which is innovative by virtually no sacrifice in performance while transition from the single-plex assays and by characteristics on the level of laboratory quantitative methods. The novel approach to easy multiplexing is realized via joining an on-demand set of single-plex LF strips, which employ magnetic nanolabels, into a miniature cylinder cartridge that mimics LF strip during all assay stages. The cartridge is read out by an original portable multichannel reader based on the magnetic particle quantification technique. The developed reader offers the unmatched 60 zmol detection limit and 7-order linear dynamic range for volumetric registration of magnetic labels inside a cartridge of several millimeters in diameter regardless of its optical transparency. Each of the test strips, developed here as building blocks for the multiplex assay, can be used "as is" for autonomous quantitative single-plex detection with the same measuring setup, exhibiting the limits of detection (LOD) of 0.22, 0.11, and 0.32 ng/mL for BoNT-A, -B, and -E, respectively. The proposed multiplex assay has demonstrated the remarkably similar LOD values of 0.20, 0.12, 0.35 ng/mL under the same conditions. The multiplex assay performance was successfully validated by BoNT detection in milk and apple and orange juices. The developed methods can be extended to other proteins and used for rapid multianalyte tests for point-of-care in vitro diagnostics, food analysis, biosafety and environmental monitoring, forensics, and security, etc.

  18. Rapid removal of uranium from aqueous solutions using magnetic Fe3O4@SiO2 composite particles.

    Science.gov (United States)

    Fan, Fang-Li; Qin, Zhi; Bai, Jing; Rong, Wei-Dong; Fan, Fu-You; Tian, Wei; Wu, Xiao-Lei; Wang, Yang; Zhao, Liang

    2012-04-01

    Rapid removal of U(VI) from aqueous solutions was investigated using magnetic Fe(3)O(4)@SiO(2) composite particles as the novel adsorbent. Batch experiments were conducted to study the effects of initial pH, amount of adsorbent, shaking time and initial U(VI) concentrations on uranium sorption efficiency as well as the desorbing of U(VI). The sorption of uranium on Fe(3)O(4)@SiO(2) composite particles was pH-dependent, and the optimal pH was 6.0. In kinetics studies, the sorption equilibrium can be reached within 180 min, and the experimental data were well fitted by the pseudo-second-order model, and the equilibrium sorption capacities calculated by the model were almost the same as those determined by experiments. The Langmuir sorption isotherm model correlates well with the uranium sorption equilibrium data for the concentration range of 20-200 mg/L. The maximum uranium sorption capacity onto magnetic Fe(3)O(4)@SiO(2) composite particles was estimated to be about 52 mg/g at 25 °C. The highest values of uranium desorption (98%) was achieved using 0.01 M HCl as the desorbing agent. Fe(3)O(4)@SiO(2) composite particles showed a good selectivity for uranium from aqueous solution with other interfering cation ions. Present study suggested that magnetic Fe(3)O(4)@SiO(2) composite particles can be used as a potential adsorbent for sorption uranium and also provided a simple, fast separation method for removal of heavy metal ion from aqueous solution. Copyright © 2011 Elsevier Ltd. All rights reserved.

  19. Rapid Colorimetric Detection of Cartap Residues by AgNP Sensor with Magnetic Molecularly Imprinted Microspheres as Recognition Elements

    Directory of Open Access Journals (Sweden)

    Mao Wu

    2018-06-01

    Full Text Available The overuse of cartap in tea tree leads to hazardous residues threatening human health. A colorimetric determination was established to detect cartap residues in tea beverages by silver nanoparticles (AgNP sensor with magnetic molecularly imprinted polymeric microspheres (Fe3O4@mSiO2@MIPs as recognition elements. Using Fe3O4 as supporting core, mesoporous SiO2 as intermediate shell, methylacrylic acid as functional monomer, and cartap as template, Fe3O4@mSiO2@MIPs were prepared to selectively and magnetically separate cartap from tea solution before colorimetric determination by AgNP sensors. The core-shell Fe3O4@mSiO2@MIPs were also characterized by FT-IR, TEM, VSM, and experimental adsorption. The Fe3O4@mSiO2@MIPs could be rapidly separated by an external magnet in 10 s with good reusability (maintained 95.2% through 10 cycles. The adsorption process of cartap on Fe3O4@mSiO2@MIPs conformed to Langmuir adsorption isotherm with maximum adsorption capacity at 0.257 mmol/g and short equilibrium time of 30 min at 298 K. The AgNP colorimetric method semi-quantified cartap ≥5 mg/L by naked eye and quantified cartap 0.1–5 mg/L with LOD 0.01 mg/L by UV-vis spectroscopy. The AgNP colorimetric detection after pretreatment with Fe3O4@mSiO2@MIPs could be successfully utilized to recognize and detect cartap residues in tea beverages.

  20. Cone-beam computed tomography evaluation of dentoskeletal changes after asymmetric rapid maxillary expansion.

    Science.gov (United States)

    Baka, Zeliha Muge; Akin, Mehmet; Ucar, Faruk Izzet; Ileri, Zehra

    2015-01-01

    The aims of this study were to quantitatively evaluate the changes in arch widths and buccolingual inclinations of the posterior teeth after asymmetric rapid maxillary expansion (ARME) and to compare the measurements between the crossbite and the noncrossbite sides with cone-beam computed tomography (CBCT). From our clinic archives, we selected the CBCT records of 30 patients with unilateral skeletal crossbite (13 boys, 14.2 ± 1.3 years old; 17 girls, 13.8 ± 1.3 years old) who underwent ARME treatment. A modified acrylic bonded rapid maxillary expansion appliance including an occlusal locking mechanism was used in all patients. CBCT records had been taken before ARME treatment and after a 3-month retention period. Fourteen angular and 80 linear measurements were taken for the maxilla and the mandible. Frontally clipped CBCT images were used for the evaluation. Paired sample and independent sample t tests were used for statistical comparisons. Comparisons of the before-treatment and after-retention measurements showed that the arch widths and buccolingual inclinations of the posterior teeth increased significantly on the crossbite side of the maxilla and on the noncrossbite side of the mandible (P ARME treatment, the crossbite side of the maxilla and the noncrossbite side of the mandible were more affected than were the opposite sides. Copyright © 2015. Published by Elsevier Inc.

  1. A Rapid Detection Method of Brucella with Quantum Dots and Magnetic Beads Conjugated with Different Polyclonal Antibodies

    Science.gov (United States)

    Song, Dandan; Qu, Xiaofeng; Liu, Yushen; Li, Li; Yin, Dehui; Li, Juan; Xu, Kun; Xie, Renguo; Zhai, Yue; Zhang, Huiwen; Bao, Hao; Zhao, Chao; Wang, Juan; Song, Xiuling; Song, Wenzhi

    2017-03-01

    Brucella spp. are facultative intracellular bacteria that cause zoonotic disease of brucellosis worldwide. Traditional methods for detection of Brucella spp. take 48-72 h that does not meet the need of rapid detection. Herein, a new rapid detection method of Brucella was developed based on polyclonal antibody-conjugating quantum dots and antibody-modified magnetic beads. First, polyclonal antibodies IgG and IgY were prepared and then the antibody conjugated with quantum dots (QDs) and immunomagnetic beads (IMB), respectively, which were activated by N-(3-dimethylaminopropyl)- N'-ethylcar-bodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS) to form probes. We used the IMB probe to separate the Brucella and labeled by the QD probe, and then detected the fluorescence intensity with a fluorescence spectrometer. The detection method takes 105 min with a limit of detection of 103 CFU/mL and ranges from 10 to 105 CFU/mL ( R 2 = 0.9983), and it can be well used in real samples.

  2. Magnetic phase transitions and large magnetic entropy change with a wide temperature span in HoZn

    Energy Technology Data Exchange (ETDEWEB)

    Li, Lingwei, E-mail: wei0396@hotmail.com [Key Laboratory of Electromagnetic Processing of Materials (Ministry of Education), Northeastern University, Shenyang 110819 (China); Institut für Anorganische und Analytische Chemie, Universität Münster, Corrensstrasse 30, D-48149 Münster (Germany); Yuan, Ye [Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Institute of Ion Beam Physics and Materials Research, P.O. Box 510119, 01314 Dresden (Germany); Zhang, Yikun [Key Laboratory of Electromagnetic Processing of Materials (Ministry of Education), Northeastern University, Shenyang 110819 (China); Pöttgen, Rainer [Institut für Anorganische und Analytische Chemie, Universität Münster, Corrensstrasse 30, D-48149 Münster (Germany); Zhou, Shengqiang [Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Institute of Ion Beam Physics and Materials Research, P.O. Box 510119, 01314 Dresden (Germany)

    2015-09-15

    Highlights: • Magnetic phase transitions and magnetocaloric effect in HoZn were studied. • The critical properties of HoZn were systematically investigated. • The obtained critical exponents are satisfied with scaling theory. • A large reversible magnetocaloric effect in HoZn was observed. • HoZn could be a promising candidate for magnetic refrigeration. - Abstract: CsCl-type HoZn undergoes two successive magnetic phase transitions: (i) paramagnetic to ferromagnetic (FM) at T{sub C} ∼ 72 K and (ii) a spin reorientation (SR) at T{sub SR} ∼ 26 K. Magnetization and modified Arrott plots indicate that HoZn undergoes a second-order magnetic phase transition around T{sub C}. The obtained critical exponents have some small deviations from the mean-field theory, indicating a short range or a local magnetic interaction which is properly related to the coexistence of FM and SR transitions at low temperature. Two successive magnetic transitions in HoZn induce one broad pronounced peak together with a shoulder in the temperature dependence of the magnetic entropy change −ΔS{sub M}(T) curves, resulting in a wide temperature range with a large relative cooling power (RCP). For a field change of 0–7 T, the maximum value of −ΔS{sub M} is 15.2 J/kg K around T{sub C} with a large RCP value of 1124 J/kg. The large reversible magnetocaloric effect (MCE) and RC indicate that HoZn is a good candidate for active magnetic refrigeration.

  3. Portable rapid gas content measurement - an opportunity for a step change in the coal industry?

    International Nuclear Information System (INIS)

    Beamish, Basil; Kizil, Mehmet; Gu, Ming

    2013-01-01

    The last major advance in gas content measurement for coal seams was the introduction of the quick crush technique in the early 1990s. This is a laboratory test method that has proven very reliable over the years. Recent laboratory testing using a portable quick crushing device, known as the portable gas content analyser, has produced consistent gas content results for a set of core samples obtained from a single borehole that intersected four coal seams. The retained gas content values obtained for the seams show the same increasing gas content pattern and gas composition change with depth as the standard quick crush technique. Use of the portable gas content analyser provides the opportunity to produce rapid, reliable gas content measurement of coal that could be developed for assessing gas compliance cores and outburst-prone conditions at a mine site.

  4. Phase field modeling of rapid crystallization in the phase-change material AIST

    Science.gov (United States)

    Tabatabaei, Fatemeh; Boussinot, Guillaume; Spatschek, Robert; Brener, Efim A.; Apel, Markus

    2017-07-01

    We carry out phase field modeling as a continuum simulation technique in order to study rapid crystallization processes in the phase-change material AIST (Ag4In3Sb67Te26). In particular, we simulate the spatio-temporal evolution of the crystallization of a molten area of the phase-change material embedded in a layer stack. The simulation model is adapted to the experimental conditions used for recent measurements of crystallization rates by a laser pulse technique. Simulations are performed for substrate temperatures close to the melting temperature of AIST down to low temperatures when an amorphous state is involved. The design of the phase field model using the thin interface limit allows us to retrieve the two limiting regimes of interface controlled (low temperatures) and thermal transport controlled (high temperatures) dynamics. Our simulations show that, generically, the crystallization velocity presents a maximum in the intermediate regime where both the interface mobility and the thermal transport, through the molten area as well as through the layer stack, are important. Simulations reveal the complex interplay of all different contributions. This suggests that the maximum switching velocity depends not only on material properties but also on the precise design of the thin film structure into which the phase-change material is embedded.

  5. Spectroscopic sensitivity of real-time, rapidly induced phytochemical change in response to damage.

    Science.gov (United States)

    Couture, John J; Serbin, Shawn P; Townsend, Philip A

    2013-04-01

    An ecological consequence of plant-herbivore interactions is the phytochemical induction of defenses in response to insect damage. Here, we used reflectance spectroscopy to characterize the foliar induction profile of cardenolides in Asclepias syriaca in response to damage, tracked in vivo changes and examined the influence of multiple plant traits on cardenolide concentrations. Foliar cardenolide concentrations were measured at specific time points following damage to capture their induction profile. Partial least-squares regression (PLSR) modeling was employed to calibrate cardenolide concentrations to reflectance spectroscopy. In addition, subsets of plants were either repeatedly sampled to track in vivo changes or modified to reduce latex flow to damaged areas. Cardenolide concentrations and the induction profile of A. syriaca were well predicted using models derived from reflectance spectroscopy, and this held true for repeatedly sampled plants. Correlations between cardenolides and other foliar-related variables were weak or not significant. Plant modification for latex reduction inhibited an induced cardenolide response. Our findings show that reflectance spectroscopy can characterize rapid phytochemical changes in vivo. We used reflectance spectroscopy to identify the mechanisms behind the production of plant secondary metabolites, simultaneously characterizing multiple foliar constituents. In this case, cardenolide induction appears to be largely driven by enhanced latex delivery to leaves following damage. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

  6. Changes in the etiology of valvular heart disease in the rapidly aging Korean population.

    Science.gov (United States)

    Jang, Shin Yi; Ju, Eun-Young; Seo, Su Ra; Choi, Ji Yeon; Park, Sung-Ji; Kim, Duk-Kyung; Park, Seung Woo

    2014-06-15

    The aim of this study is to assess the changes in the causes of valvular heart disease between 2006 and 2011 in Korea. Data were collected from the Korean National Health Insurance Service from 2006 through 2011. These data consisted of primary diagnoses related to valvular heart disease regardless of other conditions. Valvular heart disease included non-rheumatic mitral valve disorders, non-rheumatic aortic valve disorders, rheumatic mitral valve disorders, and rheumatic aortic valve disorders. Overall, the age-standardized cumulative prevalence of non-rheumatic valvular heart disease was 70.6 per 100,000 persons in 2006 and 110.3 in 2011. This represented an increase from 42.2 to 65.2 in women and from 28.4 to 45.1 in men. In particular, there was a greater increase in prevalence in patients aged 65 years or older compared with groups aged 20-44 years or 45-64 years for both genders. The age-standardized cumulative prevalence of rheumatic valve disease did not change dramatically between 2006 and 2011. The overall age-standardized cumulative prevalence of non-rheumatic valvular heart diseases increased between 2006 and 2011, especially in individuals older than 65 years. These changes should be considered in future designs of cardiovascular healthcare services in countries with a rapidly aging population. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  7. Investigation of strain-induced magnetization change in ferromagnetic microparticles

    International Nuclear Information System (INIS)

    Chuklanov, A P; Nurgazizov, N I; Bizyaev, D A; Khanipov, T F; Bukharaev, A A; Yu Petukhov, V; Chirkov, V V; Gumarov, G G

    2016-01-01

    This work is devoted to investigation of magnetoelastic strain effect on the ferromagnetic microparticles of permalloy. An original method of sample fabrication with compressed microparticles is proposed. Magnetic force microscopy and magneto-optical Kerr experiments were carried out with unstrained and compressed microparticles. The domain walls transformation in compressed microparticles is in good agreement with numerical calculations. Hard axis of magnetization was observed on the compressed sample. (paper)

  8. Rapid evolution of phenology during range expansion with recent climate change.

    Science.gov (United States)

    Lustenhouwer, Nicky; Wilschut, Rutger A; Williams, Jennifer L; van der Putten, Wim H; Levine, Jonathan M

    2018-02-01

    Although climate warming is expected to make habitat beyond species' current cold range edge suitable for future colonization, this new habitat may present an array of biotic or abiotic conditions not experienced within the current range. Species' ability to shift their range with climate change may therefore depend on how populations evolve in response to such novel environmental conditions. However, due to the recent nature of thus far observed range expansions, the role of rapid adaptation during climate change migration is only beginning to be understood. Here, we evaluated evolution during the recent native range expansion of the annual plant Dittrichia graveolens, which is spreading northward in Europe from the Mediterranean region. We examined genetically based differentiation between core and edge populations in their phenology, a trait that is likely under selection with shorter growing seasons and greater seasonality at northern latitudes. In parallel common garden experiments at range edges in Switzerland and the Netherlands, we grew plants from Dutch, Swiss, and central and southern French populations. Population genetic analysis following RAD-sequencing of these populations supported the hypothesized central France origins of the Swiss and Dutch range edge populations. We found that in both common gardens, northern plants flowered up to 4 weeks earlier than southern plants. This differentiation in phenology extended from the core of the range to the Netherlands, a region only reached from central France over approximately the last 50 years. Fitness decreased as plants flowered later, supporting the hypothesized benefits of earlier flowering at the range edge. Our results suggest that native range expanding populations can rapidly adapt to novel environmental conditions in the expanded range, potentially promoting their ability to spread. © 2017 John Wiley & Sons Ltd.

  9. Net Ecosystem Exchange of CO2 with Rapidly Changing High Arctic Landscapes

    Science.gov (United States)

    Emmerton, C. A.

    2015-12-01

    High Arctic landscapes are expansive and changing rapidly. However our understanding of their functional responses and potential to mitigate or enhance anthropogenic climate change is limited by few measurements. We collected eddy covariance measurements to quantify the net ecosystem exchange (NEE) of CO2 with polar semidesert and meadow wetland landscapes at the highest-latitude location measured to date (82°N). We coupled these rare data with ground and satellite vegetation production measurements (Normalized Difference Vegetation Index; NDVI) to evaluate the effectiveness of upscaling local to regional NEE. During the growing season, the dry polar semidesert landscape was a near zero sink of atmospheric CO2 (NEE: -0.3±13.5 g C m-2). A nearby meadow wetland accumulated over two magnitudes more carbon (NEE: -79.3±20.0 g C m-2) than the polar semidesert landscape, and was similar to meadow wetland NEE at much more southern latitudes. Polar semidesert NEE was most influenced by moisture, with wetter surface soils resulting in greater soil respiration and CO2 emissions. At the meadow wetland, soil heating enhanced plant growth, which in turn increased CO2 uptake. Our upscaling assessment found that polar semidesert NDVI measured on site was low (mean: 0.120-0.157) and similar to satellite measurements (mean: 0.155-0.163). However, weak plant growth resulted in poor satellite NDVI-NEE relationships and created challenges for remotely-detecting changes in the cycling of carbon on the polar semidesert landscape. The meadow wetland appeared more suitable to assess plant production and NEE via remote-sensing, however high Arctic wetland extent is constrained by topography to small areas that may be difficult to resolve with large satellite pixels. We predict that until summer precipitation and humidity increases substantially, climate-related changes of dry high Arctic landscapes may be restricted by poor soil moisture retention, and therefore have some inertia against

  10. MAGNET

    CERN Multimedia

    B. Curé

    2012-01-01

      The magnet and its sub-systems were stopped at the beginning of the winter shutdown on 8th December 2011. The magnet was left without cooling during the cryogenics maintenance until 17th January 2012, when the cryoplant operation resumed. The magnet temperature reached 93 K. The vacuum pumping was maintained during this period. During this shutdown, the yearly maintenance was performed on the cryogenics, the vacuum pumps, the magnet control and safety systems, and the power converter and discharge lines. Several preventive actions led to the replacement of the electrovalve command coils, and the 20A DC power supplies of the magnet control system. The filters were cleaned on the demineralised water circuits. The oil of the diffusion pumps was changed. On the cryogenics, warm nitrogen at 343 K was circulated in the cold box to regenerate the filters and the heat exchangers. The coalescing filters have been replaced at the inlet of both the turbines and the lubricant trapping unit. The active cha...

  11. Magnetic behavioural change of silane exposed graphene nanoflakes

    Energy Technology Data Exchange (ETDEWEB)

    Ray, Sekhar C., E-mail: raysc@unisa.ac.za [Department of Physics, College of Science, Engineering and Technology, University of South Africa, Private Bag X6, Florida, 1710, Science Campus, Christiaan de Wet and Pioneer Avenue, Florida Park, Johannesburg 1710 (South Africa); Mishra, D. K. [Department of Physics, College of Science, Engineering and Technology, University of South Africa, Private Bag X6, Florida, 1710, Science Campus, Christiaan de Wet and Pioneer Avenue, Florida Park, Johannesburg 1710 (South Africa); Department of Physics, Institute of Technical Research and Education, Siksha ‘O’ Anusandhan University, Khandagiri Square, Bhubaneswar 751030, Odisha (India); Strydom, A. M. [Highly Correlated Matter Research Group, Physics Department, University of Johannesburg, PO Box 524, Auckland Park 2006 (South Africa); Papakonstantinou, P. [Nanotechnology and Integrated Bioengineering Center (NIBEC), School of Engineering, University of Ulster, Jordanstown Campus, Newtownabbey BT37 0QB (United Kingdom)

    2015-09-21

    The electronic structures and magnetic properties of graphene nanoflakes (GNFs) exposed to an organo-silane precursor [tetra-methyl-silane, Si(CH{sub 3}){sub 4}] were studied using atomic force microscopy, electron field emission (EFE), x-ray photoelectron spectroscopy (XPS), and magnetization. The result of XPS indicates that silyl radical based strong covalent bonds were formed in GNFs, which induced local structural relaxations and enhanced sp{sup 3} hybridization. The EFE measurements show an increase in the turn-on electric field from 9.8 V/μm for pure GNFs to 26.3 V/μm for GNFs:Si having highest Si/(Si + C) ratio ( ≅ 0.35) that also suggests an enhancement of the non-metallic sp{sup 3} bonding in the GNFs matrix. Magnetic studies show that the saturation magnetization (Ms) is decreased from 172.53 × 10{sup −6} emu/g for pure GNFs to 13.00 × 10{sup −6} emu/g for GNFs:Si with the highest Si/(Si + C) ratio 0.35, but on the other side, the coercivity (Hc) increases from 66 to 149 Oe due to conversion of sp{sup 2} → sp{sup 3}-hybridization along with the formation of SiC and Si-O bonding in GNFs. The decrease in saturation magnetization and increase in coercivity (Hc) in GNFs on Si-functionalization are another routes to tailor the magnetic properties of graphene materials for magnetic device applications.

  12. A decade of rapid change: Biocultural influences on child growth in highland Peru.

    Science.gov (United States)

    Oths, Kathryn S; Smith, Hannah N; Stein, Max J; Lazo Landivar, Rodrigo J

    2018-03-01

    In the past decade many areas of Peru have been undergoing extreme environmental, economic, and cultural change. In the highland hamlet of Chugurpampa, La Libertad, climate change has ruined harvests and led to frequent periods of migration to the coast in search of livelihood. This biocultural research examines how the changes could be affecting the growth of children who maintain residence in the highlands. Clinical records from the early 2000s were compared to those from the early 2010s. Charts were randomly selected to record anthropometric data, netting a sample of 75 children ages 0-60 months of age. Analysis of covariance was run to compare mean stature, weight, and BMI between cohorts. Percentage of children who fall below the -2 threshold for z-scores for height and weight were compared by age and cohort. A significant secular trend in growth was found, with children born more recently larger than those born a decade before. The effect is most notable in the first year of life, with the growth advantage attenuated by the age of 3 for height and age 4 for weight. While children were unlikely to be stunted from 0 to 3 years of age, 44% of the later cohort were stunted and 11% were underweight from 4 to 5 years of age. Three possible explanations for the rapid shift are entertained: more time spent on the coast during gestation and early childhood, which may attenuate the effect of hypoxia on child growth; dietary change; and increased use of biomedicine. © 2017 Wiley Periodicals, Inc.

  13. Rapid changes in the level of Kluane Lake in Yukon Territory over the last millennium

    Science.gov (United States)

    Clague, John J.; Luckman, Brian H.; Van Dorp, Richard D.; Gilbert, Robert; Froese, Duane; Jensen, Britta J. L.; Reyes, Alberto V.

    2006-09-01

    The level of Kluane Lake, the largest lake in Yukon Territory, was lower than at present during most of the Holocene. The lake rose rapidly in the late seventeenth century to a level 12 m above present, drowning forest and stranding driftwood on a conspicuous high-stand beach, remnants of which are preserved at the south end of the lake. Kluane Lake fell back to near its present level by the end of the eighteenth century and has fluctuated within a range of about 3 m over the last 50 yr. The primary control on historic fluctuations in lake level is the discharge of Slims River, the largest source of water to the lake. We use tree ring and radiocarbon ages, stratigraphy and sub-bottom acoustic data to evaluate two explanations for the dramatic changes in the level of Kluane Lake. Our data support the hypothesis of Hugh Bostock, who suggested in 1969 that the maximum Little Ice Age advance of Kaskawulsh Glacier deposited large amounts of sediment in the Slims River valley and established the present course of Slims River into Kluane Lake. Bostock argued that these events caused the lake to rise and eventually overflow to the north. The overflowing waters incised the Duke River fan at the north end of Kluane Lake and lowered the lake to its present level. This study highlights the potentially dramatic impacts of climate change on regional hydrology during the Little Ice Age in glacierised mountains.

  14. Change of magnetic properties of nanocrystalline alloys under influence of external factors

    Science.gov (United States)

    Sitek, Jozef; Holková, Dominika; Dekan, Julius; Novák, Patrik

    2016-10-01

    Nanocrystalline (Fe3Ni1)81Nb7B12 alloys were irradiated using different types of radiation and subsequently studied by Mössbauer spectroscopy. External magnetic field of 0.5 T, electron-beam irradiation up to 4 MGy, neutron irradiation up to 1017 neutrons/cm2 and irradiation with Cu ions were applied on the samples. All types of external factors had an influence on the magnetic microstructure manifested as a change in the direction of the net magnetic moment, intensity of the internal magnetic field and volumetric fraction of the constituent phases. The direction of the net magnetic moment was the most sensitive parameter. Changes of the microscopic magnetic parameters were compared after different external influence and results of nanocrystalline samples were compared with their amorphous precursors.

  15. A planar conducting micro-loop structure for transportation of magnetic beads: An approach towards rapid sensing and quantification of biological entities

    KAUST Repository

    Gooneratne, Chinthaka Pasan

    2012-03-01

    Magnetic beads are utilized effectively in a wide variety of medical applications due to their small size, biocompatibility and large surface to volume ratio. Microfluidic lab-on-a-chip (LOC) devices, which utilize magnetic beads, are promising tools for accurate and rapid cell sorting and counting. Effective manipulation of beads is a critical factor for the performance of LOC devices. In this paper we propose a planar conducting micro-loop structure to trap, manipulate and transport magnetic beads. Current through the micro-loops produces magnetic field gradients that are proportional to the force required to manipulate the beads. Numerical analyses were performed to study the magnetic forces and their spatial distributions. Experimental results showed that magnetic beads could not only be transported towards a target region, e.g., for sensing purposes, but also the trapping rate could be increased by switching current between the different loops in the micro-loop structure. This method could lead to rapid and accurate quantification of biological entities tagged with magnetic beads. Copyright © 2012 American Scientific Publishers. All rights reserved.

  16. A new oxidation flow reactor for measuring secondary aerosol formation of rapidly changing emission sources

    Science.gov (United States)

    Simonen, Pauli; Saukko, Erkka; Karjalainen, Panu; Timonen, Hilkka; Bloss, Matthew; Aakko-Saksa, Päivi; Rönkkö, Topi; Keskinen, Jorma; Dal Maso, Miikka

    2017-04-01

    Oxidation flow reactors (OFRs) or environmental chambers can be used to estimate secondary aerosol formation potential of different emission sources. Emissions from anthropogenic sources, such as vehicles, often vary on short timescales. For example, to identify the vehicle driving conditions that lead to high potential secondary aerosol emissions, rapid oxidation of exhaust is needed. However, the residence times in environmental chambers and in most oxidation flow reactors are too long to study these transient effects ( ˜ 100 s in flow reactors and several hours in environmental chambers). Here, we present a new oxidation flow reactor, TSAR (TUT Secondary Aerosol Reactor), which has a short residence time ( ˜ 40 s) and near-laminar flow conditions. These improvements are achieved by reducing the reactor radius and volume. This allows studying, for example, the effect of vehicle driving conditions on the secondary aerosol formation potential of the exhaust. We show that the flow pattern in TSAR is nearly laminar and particle losses are negligible. The secondary organic aerosol (SOA) produced in TSAR has a similar mass spectrum to the SOA produced in the state-of-the-art reactor, PAM (potential aerosol mass). Both reactors produce the same amount of mass, but TSAR has a higher time resolution. We also show that TSAR is capable of measuring the secondary aerosol formation potential of a vehicle during a transient driving cycle and that the fast response of TSAR reveals how different driving conditions affect the amount of formed secondary aerosol. Thus, TSAR can be used to study rapidly changing emission sources, especially the vehicular emissions during transient driving.

  17. Rapid changes in water hardness and alkalinity: Calcite formation is lethal to Daphnia magna.

    Science.gov (United States)

    Bogart, Sarah J; Woodman, Samuel; Steinkey, Dylan; Meays, Cindy; Pyle, Greg G

    2016-07-15

    There is growing concern that freshwater ecosystems may be negatively affected by ever-increasing anthropogenic inputs of extremely hard, highly alkaline effluent containing large quantities of Ca(2+), Mg(2+), CO3(2-), and HCO3(-) ions. In this study, the toxicity of rapid and extreme shifts in water hardness (38-600mg/L as CaCO3) and alkalinity (30-420mg/L as CaCO3) to Daphnia magna was tested, both independently and in combination. Within these ranges, where no precipitation event occurred, shifts in water hardness and/or alkalinity were not toxic to D. magna. In contrast, 98-100% of D. magna died within 96h after exposure to 600mg/L as CaCO3 water hardness and 420mg/L as CaCO3 alkalinity (LT50 of 60h with a 95% CI of 54.2-66.0h). In this treatment, a CaCO3 (calcite) precipitate formed in the water column which was ingested by and thoroughly coated the D. magna. Calcite collected from a mining impacted stream contained embedded organisms, suggesting field streams may also experience similar conditions and possibly increased mortality as observed in the lab tests. Although further investigation is required to determine the exact fate of aquatic organisms exposed to rapid calcite precipitation in the field, we caution that negative effects may occur more quickly or at lower concentrations of water hardness and alkalinity in which we observed effects in D. magna, because some species, such as aquatic insects, are more sensitive than cladocerans to changes in ionic strength. Our results provide evidence that both calcite precipitation and the major ion balance of waters should be managed in industrially affected ecosystems and we support the development of a hardness+alkalinity guideline for the protection of aquatic life. Crown Copyright © 2016. Published by Elsevier B.V. All rights reserved.

  18. Measuring Land Change in Coastal Zone around a Rapidly Urbanized Bay

    Directory of Open Access Journals (Sweden)

    Faming Huang

    2018-05-01

    Full Text Available Urban development is a major cause for eco-degradation in many coastal regions. Understanding urbanization dynamics and underlying driving factors is crucial for urban planning and management. Land-use dynamic degree indices and intensity analysis were used to measure land changes occurred in 1990, 2002, 2009, and 2017 in the coastal zone around Quanzhou bay, which is a rapidly urbanized bay in Southeast China. The comprehensive land-use dynamic degree and interval level intensity analysis both revealed that land change was accelerating across the three time intervals in a three-kilometer-wide zone along the coastal line (zone A, while land change was fastest during the second time interval 2002–2009 in a separate terrestrial area within coastal zone (zone B. Driven by urbanization, built-up gains and cropland losses were active for all time intervals in both zones. Mudflat losses were active except in the first time interval in zone A due to the intensive sea reclamation. The gain of mangrove was active while the loss of mangrove is dormant for all three intervals in zone A. Transition level analysis further revealed the similarities and differences in processes within patterns of land changes for both zones. The transition from cropland to built-up was systematically targeted and stationary while the transition from woodland to built-up was systematically avoiding transition in both zones. Built-up tended to target aquaculture for the second and third time intervals in zone A but avoid Aquaculture for all intervals in zone B. Land change in zone A was more significant than that in zone B during the second and third time intervals at three-level intensity. The application of intensity analysis can enhance our understanding of the patterns and processes in land changes and suitable land development plans in the Quanzhou bay area. This type of investigation is useful to provide information for developing sound land use policy to achieve urban

  19. Giant irreversible positive to large reversible negative magnetic entropy change evolution in Tb-based bulk metallic glass

    International Nuclear Information System (INIS)

    Luo Qiang; Schwarz, Bjoern; Mattern, Norbert; Eckert, Juergen

    2010-01-01

    We study the effects of amorphous structure and random anisotropy on the magnetic entropy change in a series of Tb-based amorphous alloys. The amorphous structure broadens the peak of magnetic entropy change and facilitates the adjustment of properties. The peak magnetic entropy change above the spin freezing temperature first depends on the average magnetic moment approximately linearly and second on the exchange interaction and random anisotropy. Large and broad reversible negative magnetic entropy changes are observed above the spin freezing temperature and giant positive irreversible magnetic entropy changes which associate with the internal entropy production are obtained well below.

  20. Phases and rates of iron and magnetism changes during paddy soil development on calcareous marine sediment and acid Quaternary red-clay.

    Science.gov (United States)

    Huang, Laiming; Jia, Xiaoxu; Shao, Ming'an; Chen, Liumei; Han, Guangzhong; Zhang, Ganlin

    2018-01-11

    Dynamic changes in Fe oxides and magnetic properties during natural pedogenesis are well documented, but variations and controls of Fe and magnetism changes during anthropedogenesis of paddy soils strongly affected by human activities remain poorly understood. We investigated temporal changes in different Fe pools and magnetic parameters in soil profiles from two contrasting paddy soil chronosequences developed on calcareous marine sediment and acid Quaternary red clay in Southern China to understand the directions, phases and rates of Fe and magnetism evolution in Anthrosols. Results showed that paddy soil evolution under the influence of artificial submergence and drainage caused changes in soil moisture regimes and redox conditions with both time and depth that controlled Fe transport and redistribution, leading to increasing profile differentiation of Fe oxides, rapid decrease of magnetic parameters, and formation of diagnostic horizons and features, irrespective of the different parent materials. However, the initial parent material characteristics (pH, Fe content and composition, weathering degree and landscape positions) exerted a strong influence on the rates and trajectories of Fe oxides evolution as well as the phases and rates of magnetism changes. This influence diminished with time as prolonged rice cultivation drove paddy soil evolving to common pedogenic features.

  1. Cumulative effects of rapid climate and land-use changes on the Yamal Peninsula, Russia

    Science.gov (United States)

    Walker, D. A.; Leibman, M. O.; Forbes, B. C.; Epstein, H. E.

    2008-12-01

    Our principal goal is to develop better, more far-looking tools to predict the cumulative effects of resource development, climate-change, and traditional land use. Here we use remote sensing, climate-change analyses, socio-economic analyses, and vegetation-change models to examine the cumulative effects of climate change, gas development, and reindeer herding on the Yamal Peninsula in northwest Siberia as part of the Northern Eurasia Earth Science Partnership Initiative (NEESPI). We find: 1. Direct (planned) impacts of industrial activities on the Yamal Peninsula are currently local and limited in extent, but this is changing rapidly as extensive gas fields are developed and land and sea transportation corridors are developed to get the gas to market. Indirect impacts of the development at Bovanenkovo, the largest gas field, exceed the direct impacts by a factor of three, and the total area of influence of the development on the reindeer pasturelands (e.g., area where migration routes and access to pasturelands is affected) exceeds the direct impacts by a factor of about 40. 2. The trend in land-surface temperatures has co-varied with the trend in sea-ice. Low sea ice in the preceding December-March period is correlated to warmer land temperature the following summer. The sea- ice trends in the Kara Sea-Yamal region are tied to variation in the North Atlantic Oscillation index. 4. Only a small greening response to warming has been detected on the Yamal in comparison with some other areas in the Arctic (e.g. Northern Alaska). The actual effects of climate-change on vegetation are currently hard to document at the ground level because of lack of baseline and long-term ground observations and difficulty of excluding reindeer in these studies. 5. There is high potential for extensive landscape effects due to unstable sandy soils, and extremely ice-rich permafrost near the surface on slopes. 6. Two different vegetation modeling approaches are being used to predict

  2. Europe's Southeastern Gateway: Responding to Rapidly Changing Patterns of World Shipping. The University's Role

    Directory of Open Access Journals (Sweden)

    Roger E. HAMLIN

    2012-12-01

    Full Text Available World trade and transportation are changing dramatically. Energy prices and transport sustainability concerns are reinvigorating ocean freighter shipping. An ever-increasing portion of trade is in containers, and container ships are getting larger quickly. Many ports, nations and continents are not keeping up with ship size increases putting them at a trade disadvantage. Major canals and seaways must also upgrade or be rendered obsolete, causing a change in the pattern of world trade. Ports have to do more than expand vessel size limits. Port regions must also invest in infrastructure that improves multi-modal access to the port and augments hand-off of containers to smaller seaway ships, trains and trucks. With heightened security and evolving emphasis on flexible and efficient logistics, ports must become high-tech logistics hubs with improved real-time data about port throughput. Constanţa, Romania provides an example of an attempt to respond to this rapid change. Near the Danube Delta, on the Black Sea, Constanţa offers a potential southeastern gateway to Europe for the Black Sea, the Eastern Mediterranean and beyond. Ships from Asia, entering via the Suez Canal can easily access Constanţa, and thus save more than ten days of shipping time for destinations in southeastern Europe compared to shipping through Rotterdam or Hamburg. But Constanţa needs to make all the improvements mentioned above. Universities have several roles in this endeavor, including identifying and forecasting trends, providing the technical knowledge to develop high-tech logistics hubs, pursing publicprivate partnerships for infrastructure development and offering training.

  3. Rapid Environmental Change Drives Increased Land Use by an Arctic Marine Predator.

    Directory of Open Access Journals (Sweden)

    Todd C Atwood

    Full Text Available In the Arctic Ocean's southern Beaufort Sea (SB, the length of the sea ice melt season (i.e., period between the onset of sea ice break-up in summer and freeze-up in fall has increased substantially since the late 1990s. Historically, polar bears (Ursus maritimus of the SB have mostly remained on the sea ice year-round (except for those that came ashore to den, but recent changes in the extent and phenology of sea ice habitat have coincided with evidence that use of terrestrial habitat is increasing. We characterized the spatial behavior of polar bears spending summer and fall on land along Alaska's north coast to better understand the nexus between rapid environmental change and increased use of terrestrial habitat. We found that the percentage of radiocollared adult females from the SB subpopulation coming ashore has tripled over 15 years. Moreover, we detected trends of earlier arrival on shore, increased length of stay, and later departure back to sea ice, all of which were related to declines in the availability of sea ice habitat over the continental shelf and changes to sea ice phenology. Since the late 1990s, the mean duration of the open-water season in the SB increased by 36 days, and the mean length of stay on shore increased by 31 days. While on shore, the distribution of polar bears was influenced by the availability of scavenge subsidies in the form of subsistence-harvested bowhead whale (Balaena mysticetus remains aggregated at sites along the coast. The declining spatio-temporal availability of sea ice habitat and increased availability of human-provisioned resources are likely to result in increased use of land. Increased residency on land is cause for concern given that, while there, bears may be exposed to a greater array of risk factors including those associated with increased human activities.

  4. Dynamic Performance of Maximum Power Point Trackers in TEG Systems Under Rapidly Changing Temperature Conditions

    Science.gov (United States)

    Man, E. A.; Sera, D.; Mathe, L.; Schaltz, E.; Rosendahl, L.

    2016-03-01

    Characterization of thermoelectric generators (TEG) is widely discussed and equipment has been built that can perform such analysis. One method is often used to perform such characterization: constant temperature with variable thermal power input. Maximum power point tracking (MPPT) methods for TEG systems are mostly tested under steady-state conditions for different constant input temperatures. However, for most TEG applications, the input temperature gradient changes, exposing the MPPT to variable tracking conditions. An example is the exhaust pipe on hybrid vehicles, for which, because of the intermittent operation of the internal combustion engine, the TEG and its MPPT controller are exposed to a cyclic temperature profile. Furthermore, there are no guidelines on how fast the MPPT must be under such dynamic conditions. In the work discussed in this paper, temperature gradients for TEG integrated in several applications were evaluated; the results showed temperature variation up to 5°C/s for TEG systems. Electrical characterization of a calcium-manganese oxide TEG was performed at steady-state for different input temperatures and a maximum temperature of 401°C. By using electrical data from characterization of the oxide module, a solar array simulator was emulated to perform as a TEG. A trapezoidal temperature profile with different gradients was used on the TEG simulator to evaluate the dynamic MPPT efficiency. It is known that the perturb and observe (P&O) algorithm may have difficulty accurately tracking under rapidly changing conditions. To solve this problem, a compromise must be found between the magnitude of the increment and the sampling frequency of the control algorithm. The standard P&O performance was evaluated experimentally by using different temperature gradients for different MPPT sampling frequencies, and efficiency values are provided for all cases. The results showed that a tracking speed of 2.5 Hz can be successfully implemented on a TEG

  5. DNA microarray unravels rapid changes in transcriptome of MK-801 treated rat brain

    Science.gov (United States)

    Kobayashi, Yuka; Kulikova, Sofya P; Shibato, Junko; Rakwal, Randeep; Satoh, Hiroyuki; Pinault, Didier; Masuo, Yoshinori

    2015-01-01

    AIM: To investigate the impact of MK-801 on gene expression patterns genome wide in rat brain regions. METHODS: Rats were treated with an intraperitoneal injection of MK-801 [0.08 (low-dose) and 0.16 (high-dose) mg/kg] or NaCl (vehicle control). In a first series of experiment, the frontoparietal electrocorticogram was recorded 15 min before and 60 min after injection. In a second series of experiments, the whole brain of each animal was rapidly removed at 40 min post-injection, and different regions were separated: amygdala, cerebral cortex, hippocampus, hypothalamus, midbrain and ventral striatum on ice followed by DNA microarray (4 × 44 K whole rat genome chip) analysis. RESULTS: Spectral analysis revealed that a single systemic injection of MK-801 significantly and selectively augmented the power of baseline gamma frequency (30-80 Hz) oscillations in the frontoparietal electroencephalogram. DNA microarray analysis showed the largest number (up- and down- regulations) of gene expressions in the cerebral cortex (378), midbrain (376), hippocampus (375), ventral striatum (353), amygdala (301), and hypothalamus (201) under low-dose (0.08 mg/kg) of MK-801. Under high-dose (0.16 mg/kg), ventral striatum (811) showed the largest number of gene expression changes. Gene expression changes were functionally categorized to reveal expression of genes and function varies with each brain region. CONCLUSION: Acute MK-801 treatment increases synchrony of baseline gamma oscillations, and causes very early changes in gene expressions in six individual rat brain regions, a first report. PMID:26629322

  6. Effect of rapid quenching on the magnetism and magnetocaloric effect of equiatomic rare earth intermetallic compounds RNi (R = Gd, Tb and Ho)

    Energy Technology Data Exchange (ETDEWEB)

    Rajivgandhi, R. [Department of Physics, Indian Institute of Technology Madras, Chennai 600 036 (India); Arout Chelvane, J. [Defence Metallurgical Research Laboratory, Hyderabad 500 058 (India); Quezado, S.; Malik, S.K. [Departamento de F’ısica Teorica e Experimental, Universidade Federal do Rio Grande do Norte, Natal 59072-970 (Brazil); Nirmala, R., E-mail: nirmala@physics.iitm.ac.in [Department of Physics, Indian Institute of Technology Madras, Chennai 600 036 (India)

    2017-07-01

    Highlights: • Melt-spinning yields microcrystalline RNi (R = Gd, Tb and Ho) samples with texture. • The texture-induced anisotropy affects magnetic and magnetocaloric properties. • Melt-spinning helps one engineer magnetocaloric effect in rare-earth compounds. - Abstract: Magnetocaloric effect (MCE) in RNi (where R = Gd, Tb and Ho) compounds has been studied in their arc-melted and melt-spun forms. The compound GdNi has the orthorhombic CrB-type structure (Space group Cmcm, No. 63) and the compound HoNi has the orthorhombic FeB-type structure (Space group Pnma, No. 62) at room temperature regardless of their synthesis condition. However, arc-melted TbNi orders in a monoclinic structure (Space group P2{sub 1}/m, No. 11) and when it is rapidly quenched to a melt-spun form, it crystallizes in an orthorhombic structure (Space group Pnma, No. 62). The arc-melted GdNi, TbNi and HoNi compounds order ferromagnetically at ∼69 K, ∼67 K and ∼36 K (T{sub C}) respectively. While the melt-spun GdNi shows about 6 K increase in T{sub C}, the ordering temperature of TbNi remains nearly the same in both arc-melted and melt-spun forms. In contrast, a reduction in T{sub C} by about 8 K is observed in melt-spun HoNi, when compared to its arc-melted counterpart. Isothermal magnetic entropy change, ∆S{sub m}, calculated from the field dependent magnetization data indicates an enhanced relative cooling power (RCP) for melt-spun GdNi for field changes of 20 kOe and 50 kOe. A lowered RCP value is observed in melt-spun TbNi and HoNi. These changes could have resulted from the competing shape anisotropy and the granular microstructure induced by the melt-spinning process. Tailoring the MCE of rare earth intermetallic compounds by suitably controlled synthesis techniques is certainly one of the directions to go forward in the search of giant magnetocaloric materials.

  7. The role of employee assistance programs in the era of rapid change in the health care delivery system.

    Science.gov (United States)

    Sumerall, S W; Israel, A R; Brewer, R; Prew, R E

    1999-01-01

    With the rapid changes occurring in the American healthcare system, questions regarding various aspects of care have arisen. These changes have led to the need for individuals working within an Employee Assistance Program (EAP) to respond quickly and effectively to crisis situations. This article summarizes the different roles and responsibilities of EAP workers in the healthcare marketplace.

  8. Three dimensional evaluation of alveolar bone changes in response to different rapid palatal expansion activation rates

    Directory of Open Access Journals (Sweden)

    Brian LaBlonde

    Full Text Available ABSTRACT Introduction: The aim of this multi-center retrospective study was to quantify the changes in alveolar bone height and thickness after using two different rapid palatal expansion (RPE activation protocols, and to determine whether a more rapid rate of expansion is likely to cause more adverse effects, such as alveolar tipping, dental tipping, fenestration and dehiscence of anchorage teeth. Methods: The sample consisted of pre- and post-expansion records from 40 subjects (age 8-15 years who underwent RPE using a 4-banded Hyrax appliance as part of their orthodontic treatment to correct posterior buccal crossbites. Subjects were divided into two groups according to their RPE activation rates (0.5 mm/day and 0.8 mm/day; n = 20 each group. Three-dimensional images for all included subjects were evaluated using Dolphin Imaging Software 11.7 Premium. Maxillary base width, buccal and palatal cortical bone thickness, alveolar bone height, and root angulation and length were measured. Significance of the changes in the measurements was evaluated using Wilcoxon signed-rank test and comparisons between groups were done using ANOVA. Significance was defined at p ≤ 0.05. Results: RPE activation rates of 0.5 mm per day (Group 1 and 0.8 mm per day (Group 2 caused significant increase in arch width following treatment; however, Group 2 showed greater increases compared to Group 1 (p < 0.01. Buccal alveolar height and width decreased significantly in both groups. Both treatment protocols resulted in significant increases in buccal-lingual angulation of teeth; however, Group 2 showed greater increases compared to Group 1 (p < 0.01. Conclusion: Both activation rates are associated with significant increase in intra-arch widths. However, 0.8 mm/day resulted in greater increases. The 0.8 mm/day activation rate also resulted in more increased dental tipping and decreased buccal alveolar bone thickness over 0.5 mm/day.

  9. Dental arch changes associated with rapid maxillary expansion: A retrospective model analysis study

    Directory of Open Access Journals (Sweden)

    Ivor M D′Souza

    2015-01-01

    Full Text Available Introduction: Transverse deficiency of the maxilla is a common clinical problem in orthodontics and dentofacial orthopedics. Transverse maxillary deficiency, isolated or associated with other dentofacial deformities, results in esthetic and functional impairment giving rise to several clinical manifestations such as asymmetrical facial growth, positional and functional mandibular deviations, altered dentofacial esthetics, adverse periodontal responses, unstable dental tipping, and other functional problems. Orthopedic maxillary expansion is the preferred treatment approach to increase the maxillary transverse dimension in young patients by splitting of the mid palatal suture. This orthopedic procedure has lately been subject of renewed interest in orthodontic treatment mechanics because of its potential for increasing arch perimeter to alleviate crowding in the maxillary arch without adversely affecting facial profile. Hence, the present investigation was conducted to establish a correlation between transverse expansion and changes in the arch perimeter, arch width and arch length. Methods: For this purpose, 10 subjects (five males, five females were selected who had been treated by rapid maxillary expansion (RME using hyrax rapid palatal expander followed by fixed mechanotherapy (PEA. Pretreatment (T1, postexpansion (T2, and posttreatment (T3 dental models were compared for dental changes brought about by RME treatment and its stability at the end of fixed mechanotherapy. After model measurements were made, the changes between T1-T2, T2-T3 and T1-T3 were determined for each patient. The mean difference between T1-T2, T2-T3 and T1-T3 were compared to assess the effects of RME on dental arch measurements. Results are expressed as mean ± standard deviation and are compared by repeated measures analysis of variance followed by a post-hoc test. Arch perimeter changes are correlated with changes in arch widths at the canine, premolar and molar

  10. A planar conducting micro-loop structure for transportation of magnetic beads: An approach towards rapid sensing and quantification of biological entities

    KAUST Repository

    Gooneratne, Chinthaka Pasan; Giouroudi, Ioanna; Kosel, Jü rgen

    2012-01-01

    tools for accurate and rapid cell sorting and counting. Effective manipulation of beads is a critical factor for the performance of LOC devices. In this paper we propose a planar conducting micro-loop structure to trap, manipulate and transport magnetic

  11. Global changes in intensity of the Earth's magnetic field during the past 800kyr

    NARCIS (Netherlands)

    Guyodo, Yohan; Valet, Jean-Pierre

    1999-01-01

    Recent advances in palaeomagnetic and dating techniques have led to increasingly precise records of the relative intensity of the Earth’s past magnetic field at numerous field sites. The compilation and analysis of these records can provide important constraints on changes in global magnetic

  12. MAGNET

    CERN Multimedia

    B. Curé

    MAGNET During the winter shutdown, the magnet subsystems went through a full maintenance. The magnet was successfully warmed up to room temperature beginning of December 2008. The vacuum was broken later on by injecting nitrogen at a pressure just above one atmosphere inside the vacuum tank. This was necessary both to prevent any accidental humidity ingress, and to allow for a modification of the vacuum gauges on the vacuum tank and maintenance of the diffusion pumps. The vacuum gauges had to be changed, because of erratic variations on the measurements, causing spurious alarms. The new type of vacuum gauges has been used in similar conditions on the other LHC experiments and without problems. They are shielded against the stray field. The lubricants of the primary and diffusion pumps have been changed. Several minor modifications were also carried out on the equipment in the service cavern, with the aim to ease the maintenance and to allow possible intervention during operation. Spare sensors have been bough...

  13. Changing fluorescence in a streaming barium plasma due to an axial magnetic field

    International Nuclear Information System (INIS)

    Bonin, K.D.; Mason, T.G.

    1991-01-01

    The present investigations consider the case of a low-density laser-produced plasma expanding into a vacuum in the presence of an axial magnetic field. The time-integrated line intensities of neutral and singly ionized barium have been measured for magnetic fields up to 300 G. These measurements reveal three prominent changes in the intensities of individual lines as a function of increasing magnetic field: extinction, growth, and severe attenuation followed by enhancement. Measurements support a model that predicts the quenching of higher-lying transitions and the enhancement of lower-lying transitions for increasing magnetic fields

  14. Prevention and Control of Cardiovascular Disease in the Rapidly Changing Economy of China.

    Science.gov (United States)

    Wu, Yangfeng; Benjamin, Emelia J; MacMahon, Stephen

    2016-06-14

    With one-fifth of the world's total population, China's prevention and control of cardiovascular disease (CVD) may affect the success of worldwide efforts to achieve sustainable CVD reduction. Understanding China's current cardiovascular epidemic requires awareness of the economic development in the past decades. The rapid economic transformations (industrialization, marketization, urbanization, globalization, and informationalization) contributed to the aging demography, unhealthy lifestyles, and environmental changes. The latter have predisposed to increasing cardiovascular risk factors and the CVD pandemic. Rising CVD rates have had a major economic impact, which has challenged the healthcare system and the whole society. With recognition of the importance of health, initial political steps and national actions have been taken to address the CVD epidemic. Looking to the future, we recommend that 4 priorities should be taken: pursue multisectorial government and nongovernment strategies targeting the underlying causes of CVD (the whole-of-government and whole-of-society policy); give priority to prevention; reform the healthcare system to fit the nature of noncommunicable diseases; and conduct research for evidence-based, low-cost, simple, sustainable, and scalable interventions. By pursuing the 4 priorities, the pandemic of CVD and other major noncommunicable diseases in China will be reversed and the global sustainable development goal achieved. © 2016 American Heart Association, Inc.

  15. Rapid changes in genetic architecture of behavioural syndromes following colonization of a novel environment.

    Science.gov (United States)

    Karlsson Green, K; Eroukhmanoff, F; Harris, S; Pettersson, L B; Svensson, E I

    2016-01-01

    Behavioural syndromes, that is correlated behaviours, may be a result from adaptive correlational selection, but in a new environmental setting, the trait correlation might act as an evolutionary constraint. However, knowledge about the quantitative genetic basis of behavioural syndromes, and the stability and evolvability of genetic correlations under different ecological conditions, is limited. We investigated the quantitative genetic basis of correlated behaviours in the freshwater isopod Asellus aquaticus. In some Swedish lakes, A. aquaticus has recently colonized a novel habitat and diverged into two ecotypes, presumably due to habitat-specific selection from predation. Using a common garden approach and animal model analyses, we estimated quantitative genetic parameters for behavioural traits and compared the genetic architecture between the ecotypes. We report that the genetic covariance structure of the behavioural traits has been altered in the novel ecotype, demonstrating divergence in behavioural correlations. Thus, our study confirms that genetic correlations behind behaviours can change rapidly in response to novel selective environments. © 2015 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2015 European Society For Evolutionary Biology.

  16. Rapid Temperature Changes and the Early Activity on Comet 67P/Churyumov-Gerasimenko

    Science.gov (United States)

    Alí-Lagoa, V.; Delbo', M.; Libourel, G.

    2015-09-01

    The so-called “early activity” of comet 67P/Churyumov-Gerasimenko has been observed to originate mostly in parts of the concave region or “neck” between its two lobes. Since activity is driven by the sublimation of volatiles, this is a puzzling result because this area is less exposed to the Sun and is therefore expected to be cooler on average. We used a thermophysical model that takes into account thermal inertia, global self-heating, and shadowing, to compute surface temperatures of the comet. We found that, for every rotation in the 2014 August-December period, some parts of the neck region undergo the fastest temperature variations of the comet’s surface precisely because they are shadowed by their surrounding terrains. Our work suggests that these fast temperature changes are correlated to the early activity of the comet, and we put forward the hypothesis that erosion related to thermal cracking is operating at a high rate on the neck region due to these rapid temperature variations. This may explain why the neck contains some ice—as opposed to most other parts of the surface—and why it is the main source of the comet’s early activity. In a broader context, these results indicate that thermal cracking can operate faster on atmosphereless bodies with significant concavities than implied by currently available estimates.

  17. Rapid modification in the olfactory signal of ants following a change in reproductive status

    Science.gov (United States)

    Cuvillier-Hot, Virginie; Renault, Valérie; Peeters, Christian

    2005-02-01

    In insect societies, the presence and condition of egg-layers can be assessed with pheromones. Exocrine secretions are expected to vary in time in order to give up-to-date information on an individual’s reproductive physiology. In the queenless monogynous ant Streblognathus peetersi, we allowed a previously infertile high-ranking worker to accede to the alpha rank, thus triggering the onset of her oogenesis (15 replicates). We then studied her interactions with an established egg-layer from the same colony after different durations, ranging from 20 h to several days. Even though her eggs are only ready to be laid after 30 days, the new alpha was recognised within 1 2 days. Detection occurred at a distance of a few millimetres, suggesting the involvement of a pheromone with low volatility, such as cuticular hydrocarbons. When the new alpha had differentiated for >48 h, she was attacked by the established egg-layer. In all cases, low-ranking workers eventually immobilised one of the two alphas: the new alpha was the target if she had differentiated only recently, suggesting that police workers select the dominant worker with the “less fertile” odour. Using the behaviour of ants as our measure, we demonstrate that a dominant’s olfactory signal changes rapidly with a modification in her social status, and it occurs well before the onset of egg-laying.

  18. Qualification Testing Versus Quantitative Reliability Testing of PV - Gaining Confidence in a Rapidly Changing Technology: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Kurtz, Sarah [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Repins, Ingrid L [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Hacke, Peter L [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Jordan, Dirk [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Kempe, Michael D [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Whitfield, Kent [Underwriters Laboratories; Phillips, Nancy [DuPont; Sample, Tony [European Commission; Monokroussos, Christos [TUV Rheinland; Hsi, Edward [Swiss RE; Wohlgemuth, John [PowerMark Corporation; Seidel, Peter [First Solar; Jahn, Ulrike [TUV Rheinland; Tanahashi, Tadanori [National Institute of Advanced Industrial Science and Technology; Chen, Yingnan [China General Certification Center; Jaeckel, Bengt [Underwriters Laboratories; Yamamichi, Masaaki [RTS Corporation

    2017-10-05

    Continued growth of PV system deployment would be enhanced by quantitative, low-uncertainty predictions of the degradation and failure rates of PV modules and systems. The intended product lifetime (decades) far exceeds the product development cycle (months), limiting our ability to reduce the uncertainty of the predictions for this rapidly changing technology. Yet, business decisions (setting insurance rates, analyzing return on investment, etc.) require quantitative risk assessment. Moving toward more quantitative assessments requires consideration of many factors, including the intended application, consequence of a possible failure, variability in the manufacturing, installation, and operation, as well as uncertainty in the measured acceleration factors, which provide the basis for predictions based on accelerated tests. As the industry matures, it is useful to periodically assess the overall strategy for standards development and prioritization of research to provide a technical basis both for the standards and the analysis related to the application of those. To this end, this paper suggests a tiered approach to creating risk assessments. Recent and planned potential improvements in international standards are also summarized.

  19. Modeling cavitation in a rapidly changing pressure field - application to a small ultrasonic horn.

    Science.gov (United States)

    Žnidarčič, Anton; Mettin, Robert; Dular, Matevž

    2015-01-01

    Ultrasonic horn transducers are frequently used in applications of acoustic cavitation in liquids. It has been observed that if the horn tip is sufficiently small and driven at high amplitude, cavitation is very strong, and the tip can be covered entirely by the gas/vapor phase for longer time intervals. A peculiar dynamics of the attached cavity can emerge with expansion and collapse at a self-generated frequency in the subharmonic range, i.e. below the acoustic driving frequency. The term "acoustic supercavitation" was proposed for this type of cavitation Žnidarčič et al. (2014) [1]. We tested several established hydrodynamic cavitation models on this problem, but none of them was able to correctly predict the flow features. As a specific characteristic of such acoustic cavitation problems lies in the rapidly changing driving pressures, we present an improved approach to cavitation modeling, which does not neglect the second derivatives in the Rayleigh-Plesset equation. Comparison with measurements of acoustic supercavitation at an ultrasonic horn of 20kHz frequency revealed a good agreement in terms of cavity dynamics, cavity volume and emitted pressure pulsations. The newly developed cavitation model is particularly suited for simulation of cavitating flow in highly fluctuating driving pressure fields. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. A magnetic micropore chip for rapid (<1 hour) unbiased circulating tumor cell isolation and in situ RNA analysis.

    Science.gov (United States)

    Ko, Jina; Bhagwat, Neha; Yee, Stephanie S; Black, Taylor; Redlinger, Colleen; Romeo, Janae; O'Hara, Mark; Raj, Arjun; Carpenter, Erica L; Stanger, Ben Z; Issadore, David

    2017-09-12

    The use of microtechnology for the highly selective isolation and sensitive detection of circulating tumor cells has shown enormous promise. One challenge for this technology is that the small feature sizes - which are the key to this technology's performance - can result in low sample throughput and susceptibility to clogging. Additionally, conventional molecular analysis of CTCs often requires cells to be taken off-chip for sample preparation and purification before analysis, leading to the loss of rare cells. To address these challenges, we have developed a microchip platform that combines fast, magnetic micropore based negative immunomagnetic selection (>10 mL h -1 ) with rapid on-chip in situ RNA profiling (>100× faster than conventional RNA labeling). This integrated chip can isolate both rare circulating cells and cell clusters directly from whole blood and allow individual cells to be profiled for multiple RNA cancer biomarkers, achieving sample-to-answer in less than 1 hour for 10 mL of whole blood. To demonstrate the power of this approach, we applied our device to the circulating tumor cell based diagnosis of pancreatic cancer. We used a genetically engineered lineage-labeled mouse model of pancreatic cancer (KPCY) to validate the performance of our chip. We show that in a cohort of patient samples (N = 25) that this device can detect and perform in situ RNA analysis on circulating tumor cells in patients with pancreatic cancer, even in those with extremely sparse CTCs (<1 CTC mL -1 of whole blood).

  1. Fourier Transform Mass Spectrometry and Nuclear Magnetic Resonance Analysis for the Rapid and Accurate Characterization of Hexacosanoylceramide.

    Science.gov (United States)

    Ross, Charles W; Simonsick, William J; Bogusky, Michael J; Celikay, Recep W; Guare, James P; Newton, Randall C

    2016-06-28

    Ceramides are a central unit of all sphingolipids which have been identified as sites of biological recognition on cellular membranes mediating cell growth and differentiation. Several glycosphingolipids have been isolated, displaying immunomodulatory and anti-tumor activities. These molecules have generated considerable interest as potential vaccine adjuvants in humans. Accurate analyses of these and related sphingosine analogues are important for the characterization of structure, biological function, and metabolism. We report the complementary use of direct laser desorption ionization (DLDI), sheath flow electrospray ionization (ESI) Fourier transform ion cyclotron resonance mass spectrometry (FTICR MS) and high-field nuclear magnetic resonance (NMR) analysis for the rapid, accurate identification of hexacosanoylceramide and starting materials. DLDI does not require stringent sample preparation and yields representative ions. Sheath-flow ESI yields ions of the product and byproducts and was significantly better than monospray ESI due to improved compound solubility. Negative ion sheath flow ESI provided data of starting materials and products all in one acquisition as hexacosanoic acid does not ionize efficiently when ceramides are present. NMR provided characterization of these lipid molecules complementing the results obtained from MS analyses. NMR data was able to differentiate straight chain versus branched chain alkyl groups not easily obtained from mass spectrometry.

  2. Fourier Transform Mass Spectrometry and Nuclear Magnetic Resonance Analysis for the Rapid and Accurate Characterization of Hexacosanoylceramide

    Directory of Open Access Journals (Sweden)

    Charles W. Ross

    2016-06-01

    Full Text Available Ceramides are a central unit of all sphingolipids which have been identified as sites of biological recognition on cellular membranes mediating cell growth and differentiation. Several glycosphingolipids have been isolated, displaying immunomodulatory and anti-tumor activities. These molecules have generated considerable interest as potential vaccine adjuvants in humans. Accurate analyses of these and related sphingosine analogues are important for the characterization of structure, biological function, and metabolism. We report the complementary use of direct laser desorption ionization (DLDI, sheath flow electrospray ionization (ESI Fourier transform ion cyclotron resonance mass spectrometry (FTICR MS and high-field nuclear magnetic resonance (NMR analysis for the rapid, accurate identification of hexacosanoylceramide and starting materials. DLDI does not require stringent sample preparation and yields representative ions. Sheath-flow ESI yields ions of the product and byproducts and was significantly better than monospray ESI due to improved compound solubility. Negative ion sheath flow ESI provided data of starting materials and products all in one acquisition as hexacosanoic acid does not ionize efficiently when ceramides are present. NMR provided characterization of these lipid molecules complementing the results obtained from MS analyses. NMR data was able to differentiate straight chain versus branched chain alkyl groups not easily obtained from mass spectrometry.

  3. Changes in soft tissue nasal widths associated with rapid maxillary expansion in prepubertal and postpubertal subjects.

    Science.gov (United States)

    Johnson, Bret M; McNamara, James A; Bandeen, Roger L; Baccetti, Tiziano

    2010-11-01

    To evaluate changes in the soft tissue width of the nose induced by rapid maxillary expansion (RME). Data on greater alar cartilage (GAC) and alar base (AB) widths were compared with a normative sample within the same age range. This prospective study consisted of an RME sample of 79 patients treated with an RME protocol. Mean age at the start of RME treatment was 13.5 years; average duration of treatment was 6.7 months. Patients were grouped into prepubertal and postpubertal groups based on their cervical vertebral maturation (CVM) stage. AB and GAC widths were determined at three separate time points. The normative sample consisted of 437 orthodontically untreated whites, aged 10-16 years. A repeated measures analysis of variance (ANOVA) was used to determine group differences. In addition, independent sample t-tests were used to compare posttreatment nasal width values vs the untreated normative sample. Increases in AB and GAC widths of the nose in the RME sample were less than 1.5 mm. No significant differences were noted in width changes between the prepubertal and postpubertal subgroups. Comparisons of T3 values showed that on average nasal width increases were greater in the RME group than in untreated norms by 1.7 mm for the GAC measure (statistically significant), and by less than 1 mm for the AB measure. RME has no significant clinical effects on the widths of the apical base and the greater alar cartilage of the nose; no differences were observed between the two maturational subgroups.

  4. The changes of macroscopic features and microscopic structures of water under influence of magnetic field

    International Nuclear Information System (INIS)

    Pang Xiaofeng; Deng Bo

    2008-01-01

    Influences of magnetic field on microscopic structures and macroscopic properties of water are studied by the spectrum techniques of infrared, Raman, visible, ultraviolet lights and X-ray. From these investigations, we know that the magnetic fields change the distribution of molecules and electrons, cause displacements and polarization of molecules and atoms, result in changes of dipole-moment transition and vibrational states of molecules and variation of transition probability of electrons, but does not alter the constitution of molecules and atoms. These are helpful in seeking the mechanism of magnetization of water. Meanwhile, we also measure the changed rules of the surface tension force, soaking effect or angle of contact, viscosity, rheology features, refraction index, dielectric constant and electric conductivity of magnetized water relative to that of pure water. The results show that the magnetic fields increase the soaking degree and hydrophobicity of water to materials, depress its surface-tension force, diminish the viscosity of war, enhance the feature of plastic flowing of water, and increase the refraction index, dielectric constant and electric conductivity of water after magnetization. These changes are caused by the above changes of microscopic structures under the action of magnetic field. Therefore, our studies are significant in science and has practical value of applications

  5. Theory, simulation and experimental results of the acoustic detection of magnetization changes in superparamagnetic iron oxide

    Directory of Open Access Journals (Sweden)

    Borgert Jörn

    2011-06-01

    Full Text Available Abstract Background Magnetic Particle Imaging is a novel method for medical imaging. It can be used to measure the local concentration of a tracer material based on iron oxide nanoparticles. While the resulting images show the distribution of the tracer material in phantoms or anatomic structures of subjects under examination, no information about the tissue is being acquired. To expand Magnetic Particle Imaging into the detection of soft tissue properties, a new method is proposed, which detects acoustic emissions caused by magnetization changes in superparamagnetic iron oxide. Methods Starting from an introduction to the theory of acoustically detected Magnetic Particle Imaging, a comparison to magnetically detected Magnetic Particle Imaging is presented. Furthermore, an experimental setup for the detection of acoustic emissions is described, which consists of the necessary field generating components, i.e. coils and permanent magnets, as well as a calibrated microphone to perform the detection. Results The estimated detection limit of acoustic Magnetic Particle Imaging is comparable to the detection limit of magnetic resonance imaging for iron oxide nanoparticles, whereas both are inferior to the theoretical detection limit for magnetically detected Magnetic Particle Imaging. Sufficient data was acquired to perform a comparison to the simulated data. The experimental results are in agreement with the simulations. The remaining differences can be well explained. Conclusions It was possible to demonstrate the detection of acoustic emissions of magnetic tracer materials in Magnetic Particle Imaging. The processing of acoustic emission in addition to the tracer distribution acquired by magnetic detection might allow for the extraction of mechanical tissue parameters. Such parameters, like for example the velocity of sound and the attenuation caused by the tissue, might also be used to support and improve ultrasound imaging. However, the method

  6. Making the most of the magnetic and lattice entropy changes

    International Nuclear Information System (INIS)

    Pecharsky, V.K.; Gschneidner, K.A.; Mudryk, Ya.; Paudyal, Durga

    2009-01-01

    Recent discoveries of novel materials exhibiting a magnetocaloric effect that is strongly enhanced by the magnetoelastic coupling-the so-called giant magnetocaloric effect materials-stimulated an unprecedented expansion of research related both to the fundamentals of the phenomenon and potential future applications of these materials in continuous magnetic cooling near room temperature. The subject of this work is twofold. On one hand, systems exhibiting the giant magnetocaloric effect may be prone to hysteresis, and may exist in nonequilibrium, phase-separated states, thus requiring a special care when their intrinsic physical properties are of interest. On the other hand, in order to harvest most of the magnetocaloric potential of a specific compound, both the magnetic and lattice degrees of freedom of the material must be precisely controlled.

  7. A study on the changes in attractive force of magnetic attachments for overdenture.

    Science.gov (United States)

    Leem, Han-Wool; Cho, In-Ho; Lee, Jong-Hyuk; Choi, Yu-Sung

    2016-02-01

    Although magnetic attachment is used frequently for overdenture, it is reported that attractive force can be decreased by abrasion and corrosion. The purpose of this study was to establish the clinical basis about considerations and long term prognosis of overdenture using magnetic attachments by investigating the change in attractive force of magnetic attachment applied to the patients. Among the patients treated with overdenture using magnetic attachments in Dankook University Dental Hospital, attractive force records of 61 magnetic attachments of 20 subjects who re-visited from July 2013 to June 2014 were analyzed. Dental magnet tester (Aichi Micro Intelligent Co., Aichi, Japan) was used for measurement. The magnetic attachments used in this study were Magfit IP-B Flat, Magfit DX400, Magfit DX600 and Magfit DX800 (Aichi Steel Co., Aichi, Japan) filled with Neodymium (NdFeB), a rare-earth magnet. Reduction ratio of attractive force had no significant correlation with conditional variables to which attachments were applied, and was higher when the maintenance period was longer (Pattractive force was significantly higher in the subject group in which attachments were used over 9 years than within 9 years (PAttractive force of magnetic attachment is maintained regardless of conditional variables and reduction ratio increased as the maintenance period became longer. Further study on adhesive material, attachment method and design improvement to prevent detachment of magnetic attachment is needed.

  8. The Future of Coral Reefs Subject to Rapid Climate Change: Lessons from Natural Extreme Environments

    Directory of Open Access Journals (Sweden)

    Emma F. Camp

    2018-02-01

    Full Text Available Global climate change and localized anthropogenic stressors are driving rapid declines in coral reef health. In vitro experiments have been fundamental in providing insight into how reef organisms will potentially respond to future climates. However, such experiments are inevitably limited in their ability to reproduce the complex interactions that govern reef systems. Studies examining coral communities that already persist under naturally-occurring extreme and marginal physicochemical conditions have therefore become increasingly popular to advance ecosystem scale predictions of future reef form and function, although no single site provides a perfect analog to future reefs. Here we review the current state of knowledge that exists on the distribution of corals in marginal and extreme environments, and geographic sites at the latitudinal extremes of reef growth, as well as a variety of shallow reef systems and reef-neighboring environments (including upwelling and CO2 vent sites. We also conduct a synthesis of the abiotic data that have been collected at these systems, to provide the first collective assessment on the range of extreme conditions under which corals currently persist. We use the review and data synthesis to increase our understanding of the biological and ecological mechanisms that facilitate survival and success under sub-optimal physicochemical conditions. This comprehensive assessment can begin to: (i highlight the extent of extreme abiotic scenarios under which corals can persist, (ii explore whether there are commonalities in coral taxa able to persist in such extremes, (iii provide evidence for key mechanisms required to support survival and/or persistence under sub-optimal environmental conditions, and (iv evaluate the potential of current sub-optimal coral environments to act as potential refugia under changing environmental conditions. Such a collective approach is critical to better understand the future survival of

  9. Lake ecosystem response to rapid lateglacial climate changes in lake sediments from northern Poland

    Science.gov (United States)

    Słowiński, Michał; Zawiska, Izabela; Ott, Florian; Noryśkiewicz, Agnieszka M.; Apolinarska, Karina; Lutyńska, Monika; Michczyńska, Danuta J.; Brauer, Achim; Wulf, Sabine; Skubała, Piotr; Błaszkiewicz, Mirosław

    2013-04-01

    During the Late Glacial Period environment changes were triggered by climatic oscillations which in turn controlled processes like, for example, permafrost thawing, vegetation development and ground water circulation. These environmental changes are ideally recorded in lake sediments and thus can be reconstructed applying a multi-poxy approach. Here, we present the results from the Trzechowskie paleolake, located in the northern Polish lowlands (eastern part of the Pomeranian Lakeland). The site is situated on the outwash plain of the Wda River, which was formed during the Pomeranian phase of the Vistulian glaciation ca 16,000 14C yrs BP. The depression of the Trzechowskie lake basin formed after melting of a buried ice block during the Allerød (13903±170 cal yrs BP). We reconstructed environmental changes in the Trzechowskie paleolake and its catchment using biotic proxies (macrofossils, pollen, cladocera, diatoms, oribatidae mite) and geochemical proxies (δ18O, δ13C, loss-on-ignition (LOI), CaCO3 content). In addition, we carried out µ-XRF element core scanning. The chronology has been established by means of biostratigraphyAMS14C dating on plant macro remains, varve counting in laminated intervals and the late Allerød Laacher See Tephra isochrone. Our results showed that biogenic accumulation in the lake started during the Bølling. Development of coniferous forest during the Allerød with dominance of Pinus sylvestris lead to leaching of carbonates in the catchment due to low pH increasing the flux of Ca ions into the lake. In consequence calcite precipitating in the lake increased as evidences by increasing CaCO3 contents. Both biotic and physical proxies clearly reflect the rapid decrease in productivity at the onset of the Younger Dryas. We compare the data from the Trzechowskie paleolake with the Meerfelder Maar and Rehwiese lake records based on tephrochronological synchronization using the Laacher See Tephra. This study is a contribution to the

  10. Rapid change of ion energy distribution and floating potential at L/H transition in the JFT-2M tokamak

    International Nuclear Information System (INIS)

    Miura, Y.; Nagashima, K.; Okano, F.

    1994-01-01

    Rapid changes of the main ion energy distribution at transitions from L-to-H, H-to-L and during ELMs are studied with the time of flight neutral measurement in the JFT-2M tokamak. The change of the main ion energy distribution after sawtooth crash during an L-mode phase is also studied. The change of the ion energy distribution just after sawtooth crash is the same as that at L/H-transition. The floating potential measured in the SOL also shows the rapid jump to more positive just after the sawtooth crash (at the same time of the change of an ion energy distribution). This shows the increase of ion outflux in the SOL and might correspond to the change of the ion energy distribution. This may be the reason why most of H-modes are triggered by a sawtooth. (author)

  11. Rapid degradation of Congo red by molecularly imprinted polypyrrole-coated magnetic TiO2 nanoparticles in dark at ambient conditions

    International Nuclear Information System (INIS)

    Wei, Shoutai; Hu, Xiaolei; Liu, Hualong; Wang, Qiang; He, Chiyang

    2015-01-01

    Highlights: • Molecularly imprinted polypyrrole-coated magnetic TiO 2 catalyst was prepared. • The catalyst degraded Congo red rapidly in dark at ambient conditions. • Degradation mechanism was proposed according to LC–MS analysis. • The catalyst can be easily recycled by a magnet. - Abstract: A novel molecularly imprinted polymer (MIP)-coated magnetic TiO 2 nanocomposite was prepared, using methyl orange (MO) as the dummy template and pyrrole as functional monomer, for degradation of Congo red (CR). The nanocomposite was characterized by Fourier transform infrared spectroscopy, thermo-gravimetric analysis, X-ray diffraction, transmission electron microscopy, and vibrating sample magnetometer. The imprinting efficiency of the imprinted nanoparticles was investigated by static binding test, and their degradation ability toward CR was also studied. Moreover, the effects of pH, temperature, dissolved oxygen and oscillation rate on degradation rate of CR were investigated. Results showed that the imprinted nanocomposite had higher adsorption ability for MO compared with the non-imprinted one. Moreover, it could degrade CR rapidly in dark at room temperature and atmospheric pressure and could be recycled easily by a magnet with a good reusability. A degradation mechanism was proposed according to LC–MS analysis of degradation products of CR. The new imprinted nanoparticles showed high catalytic activity at ambient conditions without light illumination and additional chemicals, and therefore, it can be potentially applied to the rapid, “green” and low-cost degradation of CR in industrial printing and dyeing wastewater

  12. Rapid degradation of Congo red by molecularly imprinted polypyrrole-coated magnetic TiO{sub 2} nanoparticles in dark at ambient conditions

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Shoutai; Hu, Xiaolei; Liu, Hualong; Wang, Qiang; He, Chiyang, E-mail: chiyanghe@hotmail.com

    2015-08-30

    Highlights: • Molecularly imprinted polypyrrole-coated magnetic TiO{sub 2} catalyst was prepared. • The catalyst degraded Congo red rapidly in dark at ambient conditions. • Degradation mechanism was proposed according to LC–MS analysis. • The catalyst can be easily recycled by a magnet. - Abstract: A novel molecularly imprinted polymer (MIP)-coated magnetic TiO{sub 2} nanocomposite was prepared, using methyl orange (MO) as the dummy template and pyrrole as functional monomer, for degradation of Congo red (CR). The nanocomposite was characterized by Fourier transform infrared spectroscopy, thermo-gravimetric analysis, X-ray diffraction, transmission electron microscopy, and vibrating sample magnetometer. The imprinting efficiency of the imprinted nanoparticles was investigated by static binding test, and their degradation ability toward CR was also studied. Moreover, the effects of pH, temperature, dissolved oxygen and oscillation rate on degradation rate of CR were investigated. Results showed that the imprinted nanocomposite had higher adsorption ability for MO compared with the non-imprinted one. Moreover, it could degrade CR rapidly in dark at room temperature and atmospheric pressure and could be recycled easily by a magnet with a good reusability. A degradation mechanism was proposed according to LC–MS analysis of degradation products of CR. The new imprinted nanoparticles showed high catalytic activity at ambient conditions without light illumination and additional chemicals, and therefore, it can be potentially applied to the rapid, “green” and low-cost degradation of CR in industrial printing and dyeing wastewater.

  13. Diverse multi-decadal changes in streamflow within a rapidly urbanizing region

    Science.gov (United States)

    Diem, Jeremy E.; Hill, T. Chee; Milligan, Richard A.

    2018-01-01

    The impact of urbanization on streamflow depends on a variety of factors (e.g., climate, initial land cover, inter-basin transfers, water withdrawals, wastewater effluent, etc.). The purpose of this study is to examine trends in streamflow from 1986 to 2015 in a range of watersheds within the rapidly urbanizing Atlanta, GA metropolitan area. This study compares eight watersheds over three decades, while minimizing the influence of inter-annual precipitation variability. Population and land-cover data were used to analyze changes over approximately twenty years within the watersheds. Precipitation totals for the watersheds were estimated using precipitation totals at nearby weather stations. Multiple streamflow variables, such as annual streamflow, frequencies of high-flow days (HFDs), flashiness, and precipitation-adjusted streamflow, for the eight streams were calculated using daily streamflow data. Variables were tested for significant trends from 1986 to 2015 and significant differences between 1986-2000 and 2001-2015. Flashiness increased for all streams without municipal water withdrawals, and the four watersheds with the largest increase in developed land had significant increases in flashiness. Significant positive trends in precipitation-adjusted mean annual streamflow and HFDs occurred for the two watersheds (Big Creek and Suwanee Creek) that experienced the largest increases in development, and these were the only watersheds that went from majority forest land in 1986 to majority developed land in 2015. With a disproportionate increase in HFD occurrence during summer, Big Creek and Suwannee Creek also had a reduction in intra-annual variability of HFD occurrence. Watersheds that were already substantially developed at the beginning of the period and did not have wastewater discharge had declining streamflow. The most urbanized watershed (Peachtree Creek) had a significant decrease in streamflow, and a possible cause of the decrease was increasing

  14. Magnetic Beads-Based Sensor with Tailored Sensitivity for Rapid and Single-Step Amperometric Determination of miRNAs

    Directory of Open Access Journals (Sweden)

    Eva Vargas

    2017-11-01

    Full Text Available This work describes a sensitive amperometric magneto-biosensor for single-step and rapid determination of microRNAs (miRNAs. The developed strategy involves the use of direct hybridization of the target miRNA (miRNA-21 with a specific biotinylated DNA probe immobilized on streptavidin-modified magnetic beads (MBs, and labeling of the resulting heteroduplexes with a specific DNA–RNA antibody and the bacterial protein A (ProtA conjugated with an horseradish peroxidase (HRP homopolymer (Poly-HRP40 as an enzymatic label for signal amplification. Amperometric detection is performed upon magnetic capture of the modified MBs onto the working electrode surface of disposable screen-printed carbon electrodes (SPCEs using the H2O2/hydroquinone (HQ system. The magnitude of the cathodic signal obtained at −0.20 V (vs. the Ag pseudo-reference electrode demonstrated linear dependence with the concentration of the synthetic target miRNA over the 1.0 to 100 pM range. The method provided a detection limit (LOD of 10 attomoles (in a 25 μL sample without any target miRNA amplification in just 30 min (once the DNA capture probe-MBs were prepared. This approach shows improved sensitivity compared with that of biosensors constructed with the same anti-DNA–RNA Ab as capture instead of a detector antibody and further labeling with a Strep-HRP conjugate instead of the Poly-HRP40 homopolymer. The developed strategy involves a single step working protocol, as well as the possibility to tailor the sensitivity by enlarging the length of the DNA/miRNA heteroduplexes using additional probes and/or performing the labelling with ProtA conjugated with homopolymers prepared with different numbers of HRP molecules. The practical usefulness was demonstrated by determination of the endogenous levels of the mature target miRNA in 250 ng raw total RNA (RNAt extracted from human mammary epithelial normal (MCF-10A and cancer (MCF-7 cells and tumor tissues.

  15. Magnetic Parameter Changes in Soil and Sediments in the Presence of Hydrocarbon Contamination

    Science.gov (United States)

    Appel, E.; Porsch, K.; Rijal, M. L.; Ameen, N. N.; Kappler, A.

    2014-12-01

    Magnetic proxies were successfully used for fast and non-destructive detection of fly ash related heavy metal pollution. Correlations of magnetic signals with organic contaminants in soils and sediments were also reported; however, their significance is unclear because of co-existing heavy metal pollution. At a hydrocarbon (HC) contaminated former military airbase (Hradcany, Czech Rep.), where heavy metal contents are insignificant, we detected clearly higher magnetic concentrations at the top of the groundwater fluctuation (GWF) zone. Frequent GWF by up to ca. one meter was caused through remediation by air sparging. In this study and all previous ones magnetite was identified as the dominant phase for higher magnetic concentrations. To determine the importance of microbial activity and soil parameters on changes in magnetic susceptibility (MS) laboratory batch experiments with different microbially active and sterile soils without carbon addition and with gasoline amendment were setup. MS of these microcosms was followed weekly. Depending on the soil MS either increased or decreased by up to ~7% and remained constant afterwards. The main findings were that MS changes were mainly microbially driven and influenced by the bioavailable Fe content, the initial MS and the organic carbon content of the soils. Moreover, we tested magnetic changes in laboratory columns, filled with sand from the field site Hradcany, by simulating water level changes. The observed changes were small and hardly statistically significant. Our laboratory studies revealed that different factors influence changes in magnetic properties of soil/sediments after HC contamination, with much smaller effects than expected from anomalies observed at field sites. With the present results, the ambitious goal of using magnetic monitoring for detecting HC contaminations by oil spills seem far from practical application.

  16. A novel molecularly imprinted material based on magnetic halloysite nanotubes for rapid enrichment of 2,4-dichlorophenoxyacetic acid in water

    International Nuclear Information System (INIS)

    Zhong, Shian; Zhou, Chengyun; Zhang, Xiaona; Zhou, Hui; Li, Hui; Zhu, Xiaohong; Wang, Yan

    2014-01-01

    Graphical abstract: - Highlights: • Successful preparation of a novel type of magnetic halloysite molecularly imprinted material. • Rapid enrichment for 2,4-dichlorophenoxyacetic acid in water. • This material possesses high adsorption capacity and specific recognition to 2,4-dichlorophenoxyacetic acid. • Magnetic halloysite were synthesized by co-precipitation method. - Abstract: A new type of magnetic halloysite nanotubes molecularly imprinted polymer (MHNTs@MIP) based on halloysite nanotubes (HNTs) with embedded magnetic nanoparticles was introduced in this study. MHNTs@MIP was prepared through surface imprinting technology, using 2,4-dichlorophenoxyacetic acid (2,4-D) as a template, 4-vinylpyridine as the monomer, divinylbenzene as cross-linking agents, and 2,2-azodiisobutyronitrile as initiator. MHNTs@MIP was characterized by Fourier Transform Infrared Spectrometer, transmission electron microscopy, X-ray diffraction, and vibrating sample magnetometer. MHNTs@MIP exhibited rapid and reliable analysis with supermagnetic properties, as well as repeated use and template-specific recognition. The adsorption capacity of magnetic halloysite nanotubes non-imprinted polymer (MHNTs@NIP) and MHNTs@MIP was 10.3 mg/g and 35.2 mg/g, respectively. In the detailed discussion on specific selectivity, MHNTs@MIP can be applied as an adsorbent for sample pretreatment extraction and obtain high recoveries of about 85–94%. After extraction, high-performance liquid chromatography was used to detect 2,4-D residue in water

  17. A novel molecularly imprinted material based on magnetic halloysite nanotubes for rapid enrichment of 2,4-dichlorophenoxyacetic acid in water

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, Shian; Zhou, Chengyun; Zhang, Xiaona [School of Chemistry and Chemical Engineering, Central South University, Changsha 410083 (China); Zhou, Hui [Cancer Hospital of Xiangya Medical College, Central South University, Changsha 410013 (China); Li, Hui; Zhu, Xiaohong [School of Chemistry and Chemical Engineering, Central South University, Changsha 410083 (China); Wang, Yan, E-mail: yanwangcsu@163.com [School of Chemistry and Chemical Engineering, Central South University, Changsha 410083 (China)

    2014-07-15

    Graphical abstract: - Highlights: • Successful preparation of a novel type of magnetic halloysite molecularly imprinted material. • Rapid enrichment for 2,4-dichlorophenoxyacetic acid in water. • This material possesses high adsorption capacity and specific recognition to 2,4-dichlorophenoxyacetic acid. • Magnetic halloysite were synthesized by co-precipitation method. - Abstract: A new type of magnetic halloysite nanotubes molecularly imprinted polymer (MHNTs@MIP) based on halloysite nanotubes (HNTs) with embedded magnetic nanoparticles was introduced in this study. MHNTs@MIP was prepared through surface imprinting technology, using 2,4-dichlorophenoxyacetic acid (2,4-D) as a template, 4-vinylpyridine as the monomer, divinylbenzene as cross-linking agents, and 2,2-azodiisobutyronitrile as initiator. MHNTs@MIP was characterized by Fourier Transform Infrared Spectrometer, transmission electron microscopy, X-ray diffraction, and vibrating sample magnetometer. MHNTs@MIP exhibited rapid and reliable analysis with supermagnetic properties, as well as repeated use and template-specific recognition. The adsorption capacity of magnetic halloysite nanotubes non-imprinted polymer (MHNTs@NIP) and MHNTs@MIP was 10.3 mg/g and 35.2 mg/g, respectively. In the detailed discussion on specific selectivity, MHNTs@MIP can be applied as an adsorbent for sample pretreatment extraction and obtain high recoveries of about 85–94%. After extraction, high-performance liquid chromatography was used to detect 2,4-D residue in water.

  18. Rapid Assessment of Small Changes to Major Gun and Projectile Dynamic Parameters

    National Research Council Canada - National Science Library

    Erline, Thomas

    1997-01-01

    The U.S. Navy's 5-in 54-cal. (5"/54) gun system Mark (Mk) 45 was subjected to first-order dynamic analysis tools that allowed rapid assessment of ballistic dispersion of a typical naval high explosive projectile...

  19. Hydrothermally-induced changes in mineralogy and magnetic properties of oxidized A-type granites

    Science.gov (United States)

    Nédélec, Anne; Trindade, Ricardo; Peschler, Anne; Archanjo, Carlos; Macouin, Mélina; Poitrasson, Franck; Bouchez, Jean-Luc

    2015-01-01

    The changes in magnetic mineralogy due to the hydrothermal alteration of A-type granitic rocks have been thoroughly investigated in samples from the granite of Tana (Corsica, France), and compared with other A-type granites: Meruoca (NE Brazil), Bushveld (South Africa), Mount Scott (Wichita Mountains, Oklahoma, USA) and the stratoid hypersolvus granites of Madagascar. The altered red-colored samples and their non-altered equivalents were magnetically characterized by means of magnetic susceptibility measurements, hysteresis loops, remanent coercivity spectra, and Lowrie test. It is shown that hydrothermalization in magnetite-bearing granites is related to the formation of fine-grained magnetite and hematite, and to coeval depletion in the content of primary low-coercive coarse-grained magnetite. These mineralogical changes give typical rock magnetic signatures, namely lower susceptibility magnitudes and anisotropy degrees, prolate AMS (anisotropy of magnetic susceptibility) fabrics and increased coercivities. Optical microscopy and SEM (scanning electronic microscopy) images suggest that the orientation of the secondary magnetic minerals is related to fluid-pathways and micro-fractures formed during the hydrothermal event and therefore may be unrelated to magma emplacement and crystallization fabrics. Changes in magnetic mineralogy and grain-size distribution have also to be considered for any paleomagnetic and iron isotope studies in granites.

  20. Rapid microwave-assisted synthesis of PVP-coated ultrasmall gadolinium oxide nanoparticles for magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Vahdatkhah, Parisa [Department of Materials Science and Engineering, Sharif University of Technology (Iran, Islamic Republic of); Madaah Hosseini, Hamid Reza, E-mail: Madaah@sharif.ir [Department of Materials Science and Engineering, Sharif University of Technology (Iran, Islamic Republic of); Khodaei, Azin [Department of Materials Science and Engineering, Sharif University of Technology (Iran, Islamic Republic of); Montazerabadi, Ali Reza [Department of Medical Physics and Biomedical Engineering, Tehran University of Medical Sciences (Iran, Islamic Republic of); Irajirad, Rasoul [Biomolecular Image Analysis Group, Research Center for Molecular and Cellular Imaging, Tehran University of Medical Sciences (Iran, Islamic Republic of); Oghabian, Mohamad Ali [Biomolecular Image Analysis Group, Research Center for Molecular and Cellular Imaging, Tehran University of Medical Sciences (Iran, Islamic Republic of); Department of Medical Physics and Biomedical Engineering, Tehran University of Medical Sciences (Iran, Islamic Republic of); Delavari, Hamid H., E-mail: Hamid.delavari@modares.ac.ir [Department of Materials Engineering, Tarbiat Modares University, Tehran, PO Box 14115-143 (Iran, Islamic Republic of)

    2015-05-12

    Highlights: • A rapid microwave-assisted polyol process used to synthesize Gd{sub 2}O{sub 3} nanoparticles. • In situ surface modification of ultrasmall Gd{sub 2}O{sub 3}NPs with PVP has been performed. • Gd{sub 2}O{sub 3}NPs shows considerable increasing of relaxivity in comparison to Gd-chelates. • PVP-covered Gd{sub 2}O{sub 3}NPs show appropriate stability for approximately 15 days. • Spectrophotometric indicates the leaching of free Gd ions not occurred versus time. - Abstract: Synthesis of polyvinyl pyrrolidone (PVP) coated ultrasmall Gd{sub 2}O{sub 3} nanoparticles (NPs) with enhanced T{sub 1}-weighted signal intensity and r{sub 2}/r{sub 1} ratio close to unity is performed by a microwave-assisted polyol process. PVP coated Gd{sub 2}O{sub 3}NPs with spherical shape and uniform size of 2.5 ± 0.5 nm have been synthesized below 5 min and structure and morphology confirmed by HRTEM, XRD and FTIR. The longitudinal (r{sub 1}) and transversal relaxation (r{sub 2}) of Gd{sub 2}O{sub 3}NPs is measured by a 3 T MRI scanner. The results showed considerable increasing of relaxivity for Gd{sub 2}O{sub 3}NPs in comparison to gadolinium chelates which are commonly used for clinical magnetic resonance imaging. In addition, a mechanism for Gd{sub 2}O{sub 3}NPs formation and in situ surface modification of PVP-grafted Gd{sub 2}O{sub 3}NPs is proposed.

  1. A simple rapid process for semi-automated brain extraction from magnetic resonance images of the whole mouse head.

    Science.gov (United States)

    Delora, Adam; Gonzales, Aaron; Medina, Christopher S; Mitchell, Adam; Mohed, Abdul Faheem; Jacobs, Russell E; Bearer, Elaine L

    2016-01-15

    Magnetic resonance imaging (MRI) is a well-developed technique in neuroscience. Limitations in applying MRI to rodent models of neuropsychiatric disorders include the large number of animals required to achieve statistical significance, and the paucity of automation tools for the critical early step in processing, brain extraction, which prepares brain images for alignment and voxel-wise statistics. This novel timesaving automation of template-based brain extraction ("skull-stripping") is capable of quickly and reliably extracting the brain from large numbers of whole head images in a single step. The method is simple to install and requires minimal user interaction. This method is equally applicable to different types of MR images. Results were evaluated with Dice and Jacquard similarity indices and compared in 3D surface projections with other stripping approaches. Statistical comparisons demonstrate that individual variation of brain volumes are preserved. A downloadable software package not otherwise available for extraction of brains from whole head images is included here. This software tool increases speed, can be used with an atlas or a template from within the dataset, and produces masks that need little further refinement. Our new automation can be applied to any MR dataset, since the starting point is a template mask generated specifically for that dataset. The method reliably and rapidly extracts brain images from whole head images, rendering them useable for subsequent analytical processing. This software tool will accelerate the exploitation of mouse models for the investigation of human brain disorders by MRI. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Magnetic Resonance Imaging Biomarkers to Assess Substantia Nigra Damage in Idiopathic Rapid Eye Movement Sleep Behavior Disorder.

    Science.gov (United States)

    Pyatigorskaya, Nadya; Gaurav, Rahul; Arnaldi, Dario; Leu-Semenescu, Smaranda; Yahia-Cherif, Lydia; Valabregue, Romain; Vidailhet, Marie; Arnulf, Isabelle; Lehéricy, Stephane

    2017-11-01

    Idiopathic rapid eye movement sleep behavior disorder (iRBD) is considered to be a prodromal stage of Parkinson's disease (PD). At PD onset, 40 to 70% of the dopaminergic neurons in the substantia nigra (SN) are already lost. Thus, milder SN damage is expected in participants with iRBD. We aimed to quantify SN damage in participants with iRBD using multimodal magnetic resonance imaging (MRI) and to determine biomarker efficacy in preclinical Parkinsonism. Nineteen participants with iRBD and 18 controls underwent 3-Tesla MRI, including diffusion tensor imaging, neuromelanin (NM)-sensitive imaging, and T2* mapping. Regions of interest in the SN area were drawn in NM-sensitive and T2-weighted images. The volume and normalized signal intensity in NM-sensitive images, R2*, and diffusion tensor measures were quantified in the SN. Additionally, two raters performed visual analysis of the SN using the NM-sensitive images. Participants with iRBD showed a reduction in the NM-sensitive volume and signal intensity and a decrease in fractional anisotropy (FA) versus controls, but showed no differences in axial, radial, or mean diffusivity or in R2*. For NM-sensitive volume and signal intensity, the receiver operating characteristic analysis discriminated between participants with iRBD and controls with a diagnostic accuracy of 0.86 and 0.79, respectively, whereas the accuracy was 0.77 for FA. The three biomarkers had a combined accuracy of 0.92. The fraction of participants correctly characterized by visual assessment was 0.81. NM-sensitive imaging and FA allowed for the detection of SN damage in participants with iRBD with good diagnostic accuracy. These measures may represent valuable biomarkers for prodromal Parkinsonism. © Sleep Research Society 2017. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.

  3. Physical mechanism causing rapid changes in ultrarelativistic electron pitch angle distributions right after a shock arrival: Evaluation of an electron dropout event

    Science.gov (United States)

    Zhang, X.-J.; Li, W.; Thorne, R. M.; Angelopoulos, V.; Ma, Q.; Li, J.; Bortnik, J.; Nishimura, Y.; Chen, L.; Baker, D. N.; Reeves, G. D.; Spence, H. E.; Kletzing, C. A.; Kurth, W. S.; Hospodarsky, G. B.; Blake, J. B.; Fennell, J. F.

    2016-09-01

    Three mechanisms have been proposed to explain relativistic electron flux depletions (dropouts) in the Earth's outer radiation belt during storm times: adiabatic expansion of electron drift shells due to a decrease in magnetic field strength, magnetopause shadowing and subsequent outward radial diffusion, and precipitation into the atmosphere (driven by EMIC wave scattering). Which mechanism predominates in causing electron dropouts commonly observed in the outer radiation belt is still debatable. In the present study, we evaluate the physical mechanism that may be primarily responsible for causing the sudden change in relativistic electron pitch angle distributions during a dropout event observed by Van Allen Probes during the main phase of the 27 February 2014 storm. During this event, the phase space density of ultrarelativistic (>1 MeV) electrons was depleted by more than 1 order of magnitude over the entire radial extent of the outer radiation belt (3 pitch angle distribution under a compressed magnetic field topology based on actual solar wind conditions. Although these ultrarelativistic electrons exhibit highly anisotropic (peaked in 90°), energy-dependent pitch angle distributions, which appear to be associated with the typical EMIC wave scattering, comparison of the modeled electron distribution to electron measurements indicates that drift shell splitting is responsible for this rapid change in electron pitch angle distributions. This further indicates that magnetopause loss is the predominant cause of the electron dropout right after the shock arrival.

  4. Physical mechanism causing rapid changes in ultrarelativistic electron pitch angle distributions right after a shock arrival: Evaluation of an electron dropout event: Drift Shell Splitting on the Dayside

    International Nuclear Information System (INIS)

    Zhang, X.-J.; University of California, Los Angeles, CA; Li, W.; Boston University, MA; Thorne, R. M.

    2016-01-01

    Three mechanisms have been proposed to explain relativistic electron flux depletions (dropouts) in the Earth's outer radiation belt during storm times: adiabatic expansion of electron drift shells due to a decrease in magnetic field strength, magnetopause shadowing and subsequent outward radial diffusion, and precipitation into the atmosphere (driven by EMIC wave scattering). Which mechanism predominates in causing electron dropouts commonly observed in the outer radiation belt is still debatable. In the present study, we evaluate the physical mechanism that may be primarily responsible for causing the sudden change in relativistic electron pitch angle distributions during a dropout event observed by Van Allen Probes during the main phase of the 27 February 2014 storm. During this event, the phase space density of ultrarelativistic (>1MeV) electrons was depleted by more than 1 order of magnitude over the entire radial extent of the outer radiation belt (3 < L* < 5) in less than 6 h after the passage of an interplanetary shock. We model the electron pitch angle distribution under a compressed magnetic field topology based on actual solar wind conditions. Although these ultrarelativistic electrons exhibit highly anisotropic (peaked in 90°), energy-dependent pitch angle distributions, which appear to be associated with the typical EMIC wave scattering, comparison of the modeled electron distribution to electron measurements indicates that drift shell splitting is responsible for this rapid change in electron pitch angle distributions. This further indicates that magnetopause loss is the predominant cause of the electron dropout right after the shock arrival.

  5. Organizational Adaptation to the Rapidly Changing External Environment: A Case Study of Strategic Marketing at Notre Dame College in Ohio

    Science.gov (United States)

    Brown, Shawn M.

    2012-01-01

    This thesis examined the role of strategic marketing in organizational adaptation to a rapidly changing and competitive external environment among institutions of higher education. Colleges and universities adapt to external pressures as open systems operating within a broader external environment (Bess & Dee, 2008; Keller, 1983). How does…

  6. Neolithisation of the Aegean and Southeast Europe during the 6600–6000 calBC period of Rapid Climate Change

    Directory of Open Access Journals (Sweden)

    Bernhard Weninger

    2014-12-01

    Full Text Available In extension of the recently established ‘Rapid Climate Change (RCC Neolithisation Model’ (Clare 2013, in the present paper we demonstrate the existence of a remarkable coincidence between the exact (decadel-scale entry and departure dates of the Neolithic into/from the Aegean (~6600/6050 calBC with begin/end of RCC-conditions.

  7. MAGNET

    CERN Multimedia

    B. Curé

    During the winter shutdown, the magnet subsystems went through a full maintenance. The magnet was successfully warmed up to room temperature beginning of December 2008. The vacuum was broken later on by injecting nitrogen at a pressure just above one atmosphere inside the vacuum tank. This was necessary both to prevent any accidental humidity ingress, and to allow for a modification of the vacuum gauges on the vacuum tank and maintenance of the diffusion pumps. The vacuum gauges had to be changed, because of erratic variations on the measurements, causing spurious alarms. The new type of vacuum gauges has been used in similar conditions on the other LHC experiments and without problems. They are shielded against the stray field. The lubricants of the primary and diffusion pumps have been changed. Several minor modifications were also carried out on the equipment in the service cavern, with the aim to ease the maintenance and to allow possible intervention during operation. Spare sensors have been bought. Th...

  8. Large resistance change on magnetic tunnel junction based molecular spintronics devices

    Science.gov (United States)

    Tyagi, Pawan; Friebe, Edward

    2018-05-01

    Molecular bridges covalently bonded to two ferromagnetic electrodes can transform ferromagnetic materials and produce intriguing spin transport characteristics. This paper discusses the impact of molecule induced strong coupling on the spin transport. To study molecular coupling effect the octametallic molecular cluster (OMC) was bridged between two ferromagnetic electrodes of a magnetic tunnel junction (Ta/Co/NiFe/AlOx/NiFe/Ta) along the exposed side edges. OMCs induced strong inter-ferromagnetic electrode coupling to yield drastic changes in transport properties of the magnetic tunnel junction testbed at the room temperature. These OMCs also transformed the magnetic properties of magnetic tunnel junctions. SQUID and ferromagnetic resonance studies provided insightful data to explain transport studies on the magnetic tunnel junction based molecular spintronics devices.

  9. Rapid learning of magnetic compass direction by C57BL/6 mice in a 4-armed 'plus' water maze.

    Directory of Open Access Journals (Sweden)

    John B Phillips

    Full Text Available Magnetoreception has been demonstrated in all five vertebrate classes. In rodents, nest building experiments have shown the use of magnetic cues by two families of molerats, Siberian hamsters and C57BL/6 mice. However, assays widely used to study rodent spatial cognition (e.g. water maze, radial arm maze have failed to provide evidence for the use of magnetic cues. Here we show that C57BL/6 mice can learn the magnetic direction of a submerged platform in a 4-armed (plus water maze. Naïve mice were given two brief training trials. In each trial, a mouse was confined to one arm of the maze with the submerged platform at the outer end in a predetermined alignment relative to magnetic north. Between trials, the training arm and magnetic field were rotated by 180(° so that the mouse had to swim in the same magnetic direction to reach the submerged platform. The directional preference of each mouse was tested once in one of four magnetic field alignments by releasing it at the center of the maze with access to all four arms. Equal numbers of responses were obtained from mice tested in the four symmetrical magnetic field alignments. Findings show that two training trials are sufficient for mice to learn the magnetic direction of the submerged platform in a plus water maze. The success of these experiments may be explained by: (1 absence of alternative directional cues (2, rotation of magnetic field alignment, and (3 electromagnetic shielding to minimize radio frequency interference that has been shown to interfere with magnetic compass orientation of birds. These findings confirm that mice have a well-developed magnetic compass, and give further impetus to the question of whether epigeic rodents (e.g., mice and rats have a photoreceptor-based magnetic compass similar to that found in amphibians and migratory birds.

  10. Rapid learning of magnetic compass direction by C57BL/6 mice in a 4-armed 'plus' water maze.

    Science.gov (United States)

    Phillips, John B; Youmans, Paul W; Muheim, Rachel; Sloan, Kelly A; Landler, Lukas; Painter, Michael S; Anderson, Christopher R

    2013-01-01

    Magnetoreception has been demonstrated in all five vertebrate classes. In rodents, nest building experiments have shown the use of magnetic cues by two families of molerats, Siberian hamsters and C57BL/6 mice. However, assays widely used to study rodent spatial cognition (e.g. water maze, radial arm maze) have failed to provide evidence for the use of magnetic cues. Here we show that C57BL/6 mice can learn the magnetic direction of a submerged platform in a 4-armed (plus) water maze. Naïve mice were given two brief training trials. In each trial, a mouse was confined to one arm of the maze with the submerged platform at the outer end in a predetermined alignment relative to magnetic north. Between trials, the training arm and magnetic field were rotated by 180(°) so that the mouse had to swim in the same magnetic direction to reach the submerged platform. The directional preference of each mouse was tested once in one of four magnetic field alignments by releasing it at the center of the maze with access to all four arms. Equal numbers of responses were obtained from mice tested in the four symmetrical magnetic field alignments. Findings show that two training trials are sufficient for mice to learn the magnetic direction of the submerged platform in a plus water maze. The success of these experiments may be explained by: (1) absence of alternative directional cues (2), rotation of magnetic field alignment, and (3) electromagnetic shielding to minimize radio frequency interference that has been shown to interfere with magnetic compass orientation of birds. These findings confirm that mice have a well-developed magnetic compass, and give further impetus to the question of whether epigeic rodents (e.g., mice and rats) have a photoreceptor-based magnetic compass similar to that found in amphibians and migratory birds.

  11. On the determination of the magnetic entropy change in materials with first-order transitions

    International Nuclear Information System (INIS)

    Caron, L.; Ou, Z.Q.; Nguyen, T.T.; Cam Thanh, D.T.; Tegus, O.; Brueck, E.

    2009-01-01

    An accurate method to determine the magnetic entropy change in materials with hysteretic first-order transitions is presented, which is needed to estimate their potential for applications. We have investigated the effect of the maximal entropy change derived from magnetization measurements performed in different measurement processes. The results show that the isothermal entropy change can be derived from the Maxwell relations even for samples with large thermal hysteresis. In the temperature region with hysteresis, overestimating the entropy change can be avoided by measuring the isothermal magnetization of the sample after it is cooled from the paramagnetic state to the measurement temperature. In this way the so-called peak effect is not observed as shown here for a few compounds.

  12. Gradual pressure-induced change in the magnetic structure of the noncollinear antiferromagnet Mn3Ge

    Science.gov (United States)

    Sukhanov, A. S.; Singh, Sanjay; Caron, L.; Hansen, Th.; Hoser, A.; Kumar, V.; Borrmann, H.; Fitch, A.; Devi, P.; Manna, K.; Felser, C.; Inosov, D. S.

    2018-06-01

    By means of powder neutron diffraction we investigate changes in the magnetic structure of the coplanar noncollinear antiferromagnet Mn3Ge caused by an application of hydrostatic pressure up to 5 GPa. At ambient conditions the kagomé layers of Mn atoms in Mn3Ge order in a triangular 120∘ spin structure. Under high pressure the spins acquire a uniform out-of-plane canting, gradually transforming the magnetic texture to a noncoplanar configuration. With increasing pressure the canted structure fully transforms into the collinear ferromagnetic one. We observed that magnetic order is accompanied by a noticeable magnetoelastic effect, namely, spontaneous magnetostriction. The latter induces an in-plane magnetostrain of the hexagonal unit cell at ambient pressure and flips to an out-of-plane strain at high pressures in accordance with the change of the magnetic structure.

  13. Lifting particle coordinate changes of magnetic moment type to Vlasov-Maxwell Hamiltonian dynamics

    International Nuclear Information System (INIS)

    Morrison, P. J.; Vittot, M.; Guillebon, L. de

    2013-01-01

    Techniques for coordinate changes that depend on both dependent and independent variables are developed and applied to the Maxwell-Vlasov Hamiltonian theory. Particle coordinate changes with a new velocity variable dependent on the magnetic field, with spatial coordinates unchanged, are lifted to the field theoretic level, by transforming the noncanonical Poisson bracket and Hamiltonian structure of the Vlasov-Maxwell dynamics. Several examples are given including magnetic coordinates, where the velocity is decomposed into components parallel and perpendicular to the local magnetic field, and the case of spherical velocity coordinates. An example of the lifting procedure is performed to obtain a simplified version of gyrokinetics, where the magnetic moment is used as a coordinate and the dynamics is reduced by elimination of the electric field energy in the Hamiltonian.

  14. Probing the mechanical properties, conformational changes, and interactions of nucleic acids with magnetic tweezers.

    Science.gov (United States)

    Kriegel, Franziska; Ermann, Niklas; Lipfert, Jan

    2017-01-01

    Nucleic acids are central to the storage and transmission of genetic information. Mechanical properties, along with their sequence, both enable and fundamentally constrain the biological functions of DNA and RNA. For small deformations from the equilibrium conformations, nucleic acids are well described by an isotropic elastic rod model. However, external forces and torsional strains can induce conformational changes, giving rise to a complex force-torque phase diagram. This review focuses on magnetic tweezers as a powerful tool to precisely determine both the elastic parameters and conformational transitions of nucleic acids under external forces and torques at the single-molecule level. We review several variations of magnetic tweezers, in particular conventional magnetic tweezers, freely orbiting magnetic tweezers and magnetic torque tweezers, and discuss their characteristic capabilities. We then describe the elastic rod model for DNA and RNA and discuss conformational changes induced by mechanical stress. The focus lies on the responses to torque and twist, which are crucial in the mechanics and interactions of nucleic acids and can directly be measured using magnetic tweezers. We conclude by highlighting several recent studies of nucleic acid-protein and nucleic acid-small-molecule interactions as further applications of magnetic tweezers and give an outlook of some exciting developments to come. Copyright © 2016. Published by Elsevier Inc.

  15. Structural changes in microferrogels cross-linked by magnetically anisotropic particles

    Energy Technology Data Exchange (ETDEWEB)

    Ryzhkov, A.V., E-mail: ryzhkov.a@icmm.ru [Perm National Research Polytechnic University, Perm 614990 (Russian Federation); Institute of Continuous Media Mechanics, Russian Academy of Sciences, Ural Branch, Perm 614013 (Russian Federation); Raikher, Yu. L. [Institute of Continuous Media Mechanics, Russian Academy of Sciences, Ural Branch, Perm 614013 (Russian Federation)

    2017-06-01

    Chaining of magnetic nanoparticles in a microscopic ferrogel (MFG) due to interparticle interaction and external field is analyzed by the coarse-grained molecular dynamics. The embedded nanoparticles, unlike existing conventional models, are assumed to possess uniaxial magnetic anisotropy. By that, the consideration is brought closer to reality. Evolution of particle chains, both in length and straightness, is handled with the aid of “axial” radial distribution function that is sensitive to orientation of the aggregates. The effect of the particle magnetic anisotropy on the structural alterations as well as on volume changes of MFGs is demonstrated.

  16. Interplanetary magnetic field associated changes in cosmic ray intensity and geomagnetic field during 1973-75

    International Nuclear Information System (INIS)

    Singh, R.L.; Shukla, J.P.; Shukla, A.K.; Sharma, S.M.; Agrawal, S.P.

    1979-01-01

    The effects of interplanetary magnetic field (IMF) B and its Bsub(z) component on cosmic ray intensity and geomagnetic field variations have been examined for the period 1973-75. It is observed that: (1) B >= 10γ (magnetic blobs) is pre-requisite in producing cosmic ray intensity and geomagnetic field variations of varying magnitudes, (2) the longer existence of magnetic blobs on successive days produces larger decreases in cosmic ray intensity and geomagnetic field and (3) the southward component (Bsub(z)) of IMF generally gives rise to large Asub(p) changes, though it is not effective in producing cosmic ray intensity decreases. (auth.)

  17. Rapid fluvial aggradation in response to climate change in northwestern Argentina

    Science.gov (United States)

    Wickert, Andrew; Schildgen, Taylor; Strecker, Manfred

    2015-04-01

    River channels near the edge of the northwestern Argentine Andes are rapidly aggrading at present, with preliminary estimates suggesting rates of ~20 cm yr-1. This mirrors cycles of extensive aggradation over the past 100,000 years that formed pronounced fill terraces along regional valley networks and record periods in which in which climate-driven sediment supply overcame uplift-driven river incision (Robinson et al, 2005). Here we use the new SedFlow model (Heimann et al., 2014) to help us understand the causes and spread of aggradation across these basins in the modern system, with the additional eventual goal to better interpret the geologic record. We provide field-derived grain-size distributions, field-measured and remotely-sensed channel widths and valley slopes, and a variety of possible sediment source locations and amounts as inputs to SedFlow, which routes sediment through the fluvial channel network to produce time-evolving predictions of aggradation and incision. We compare these predictions against changes in topography measured by IceSAT (Zwally et al., 2014) and field surveys. We initially test the system response to a series of isolated sediment inputs to observe interactions between tributary systems and the mainstem river. Recent observations indicate that debris-flow induced landslides are important contributors to aggradation in these rivers (Cencetti and Rivelli, 2011). These and other sediment production and transport processes are likely driven by variations in the El Niño Southern Oscillation (ENSO) (Bookhagen and Strecker, 2009). Therefore, we then run SedFlow with sediment inputs distributed across the landscape based on locations where ENSO influences may trigger enhanced landsliding. These model experiments help us towards our end goal of providing a more quantitative basis to interpret field observations of landscape response to changing patterns of precipitation. References: Bookhagen, B. and Strecker, M.: Amazonia: Landscape and

  18. Change in the flow curves of non-Newtonian oils due to a magnetic field

    International Nuclear Information System (INIS)

    Veliev, F.G.

    1979-01-01

    The effect of a variable magnetic field on the rheological properties of non-Newtonian fluids is evaluated. Bituminous pitch oils were analyzed by recording the flow curves Q.Q(Δp) - the dependence of the volumetric flow rate on the pressure gradient - with and without a field. The results obtained indicate that variable magnetic fields can produce obvious changes in the rheological properties of bituminous pitch oils, although they are nonmagnetoactive and practically electrically nonconducting

  19. We really need to talk: adapting FDA processes to rapid change.

    Science.gov (United States)

    Lykken, Sara

    2013-01-01

    The rapidly evolving realm of modern commerce strains traditional regulatory paradigms. This paper traces the historical evolution of FDA crisis-response regulation and provides examples of ways in which the definitions and procedures resulting from that past continue to be challenged by new products as market entrants, some in good faith and others not, take actions that create disconnects between actual product and marketing controls and those that consumers might expect. The paper then explores some of the techniques used by other federal agencies that have faced similar challenges in environments characterized by rapid innovation, and draws from this analysis suggestions for improvement of the FDA's warning letter system.

  20. Magnets

    International Nuclear Information System (INIS)

    Young, I.R.

    1984-01-01

    A magnet pole piece for an NMR imaging magnet is made of a plurality of magnetic wires with one end of each wire held in a non-magnetic spacer, the other ends of the wires being brought to a pinch, and connected to a magnetic core. The wires may be embedded in a synthetic resin and the magnetisation and uniformity thereof can be varied by adjusting the density of the wires at the spacer which forms the pole piece. (author)

  1. Magnetic entropy change and critical exponents in double perovskite Y2NiMnO6

    Science.gov (United States)

    Sharma, G.; Tripathi, T. S.; Saha, J.; Patnaik, S.

    2014-11-01

    We report the magnetic entropy change (ΔSM) and the critical exponents in the double perovskite manganite Y2NiMnO6 with a ferromagnetic to paramagnetic transition TC~85 K. For a magnetic field change ΔH=80 kOe, a maximum magnetic entropy change ΔSM=-6.57 J/kg K is recorded around TC. The critical exponents β=0.363±0.05 and γ=1.331±0.09 obtained from power law fitting to spontaneous magnetization MS(T) and the inverse initial susceptibility χ0-1(T) satisfy well to values derived for a 3D-Heisenberg ferromagnet. The critical exponent δ=4.761±0.129 is determined from the isothermal magnetization at TC. The scaling exponents corresponding to second order phase transition are consistent with the exponents from Kouvel-Fisher analysis and satisfy Widom's scaling relation δ=1+(γ/β). Additionally, they also satisfy the single scaling equation M(H,ɛ)=ɛβf±(H/ɛ) according to which the magnetization-field-temperature data around TC should collapse into two curves for temperatures below and above TC.

  2. Grain refining effect of magnetic field on Mg2Ni0.8Mn0.2 hydrogen storage alloys during rapid quenching

    International Nuclear Information System (INIS)

    Jiang, Chenxi; Wang, Haiyan; Chen, Xiangrong; Tang, Yougen; Lu, Zhouguang; Wang, Yazhi; Liu, Zuming

    2013-01-01

    The effect of static magnetic field treatment for synthesis of Mg 2 Ni 0.8 Mn 0.2 alloys during rapid quenching was investigated in this paper. X-ray diffraction (XRD) and scanning electron microscope (SEM) results show that the transversal static magnetic field can effectively refine the grain size, producing nanocrystalline inside. This distinct phenomenon is probably attributed to the Lorentz force suppressing the crystallization of the hydrogen storage alloys and the thermoelectric effect. Mainly due to the grain refinement, the discharge capacity of Mg 2 Ni 0.8 Mn 0.2 alloy is raised from 79 to about 200 mA h g −1 . It is confirmed that Mg 2 Ni 0.8 Mn 0.2 alloy by magnetic field assisted approach possesses enhanced electrochemical kinetics and relatively high corrosion resistance against the alkaline solution, thus resulting in higher electrochemical properties

  3. Beyond naturalness: Adapting wilderness stewardship to an era of rapid global change

    Science.gov (United States)

    David N. Cole

    2012-01-01

    Climate change and its effects are writ large across wilderness landscapes. They always have been and always will be (see Figure 1). But contemporary change is different. For the first time, the pace and direction of climate change appear to be driven significantly by human activities (IPCC 2007), and this change is playing out across landscapes already affected by...

  4. A current-pulsed power supply with rapid rising and falling edges for magnetic perturbation coils on the J-TEXT tokamak

    International Nuclear Information System (INIS)

    Yan, M.X.; Rao, B.; Ding, Y.H.; Hu, Q.M.; Hu, F.R.; Li, D.; Li, M.; Ji, X.K.; Xu, G.; Zheng, W.; Jiang, Z.H.

    2017-01-01

    Highlights: • The power supply is required to have rapid rising and falling edges. • A modified topology based on the buck chopper of current-pulsed power supply is presented and analyzed. • An entity meeting the electrical requirements has been constructed. • The spike voltage of IGBT is qualitatively analyzed. - Abstract: This study presents the design and principle of a current-pulsed power supply (CPPS) for the tearing mode (TM) feedback control of the J-TEXT tokamak. CPPS is a new method of stabilizing large magnetic islands and accelerating mode rotation through the use of modulated magnetic perturbation. In this application, continuous magnetic perturbation pulse trains with frequency of 1 kHz to kHz, amplitude of 0.25 G, and duty ratio of 20%–50% are required generating via in-vessel magnetic coils. A modified topology based on buck chopper is raised to satisfy the demands of inductive load. This modified topology is characterized by high frequency, rapid rising and falling edges, and large amplitude of current pulses. Appropriate RCD snubber circuit is applied to protect the Insulated Gate Bipolar Transistor (IGBT) switch device. Equipment with peak current that reaches 1 kA, frequency that ranges from 1 kHz to 3 kHz, and rising and falling time within 100 μs was constructed and applied to physical experiment.

  5. A current-pulsed power supply with rapid rising and falling edges for magnetic perturbation coils on the J-TEXT tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Yan, M.X. [State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan 430074 (China); College of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China); Rao, B., E-mail: borao@hust.edu.cn [State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan 430074 (China); College of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China); Ding, Y.H.; Hu, Q.M.; Hu, F.R.; Li, D.; Li, M.; Ji, X.K.; Xu, G.; Zheng, W.; Jiang, Z.H. [State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan 430074 (China); College of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China)

    2017-02-15

    Highlights: • The power supply is required to have rapid rising and falling edges. • A modified topology based on the buck chopper of current-pulsed power supply is presented and analyzed. • An entity meeting the electrical requirements has been constructed. • The spike voltage of IGBT is qualitatively analyzed. - Abstract: This study presents the design and principle of a current-pulsed power supply (CPPS) for the tearing mode (TM) feedback control of the J-TEXT tokamak. CPPS is a new method of stabilizing large magnetic islands and accelerating mode rotation through the use of modulated magnetic perturbation. In this application, continuous magnetic perturbation pulse trains with frequency of 1 kHz to kHz, amplitude of 0.25 G, and duty ratio of 20%–50% are required generating via in-vessel magnetic coils. A modified topology based on buck chopper is raised to satisfy the demands of inductive load. This modified topology is characterized by high frequency, rapid rising and falling edges, and large amplitude of current pulses. Appropriate RCD snubber circuit is applied to protect the Insulated Gate Bipolar Transistor (IGBT) switch device. Equipment with peak current that reaches 1 kA, frequency that ranges from 1 kHz to 3 kHz, and rising and falling time within 100 μs was constructed and applied to physical experiment.

  6. MAGNET

    CERN Multimedia

    Benoit Curé

    The magnet subsystems resumed operation early this spring. The vacuum pumping was restarted mid March, and the cryogenic power plant was restarted on March 30th. Three and a half weeks later, the magnet was at 4.5 K. The vacuum pumping system is performing well. One of the newly installed vacuum gauges had to be replaced at the end of the cool-down phase, as the values indicated were not coherent with the other pressure measurements. The correction had to be implemented quickly to be sure no helium leak could be at the origin of this anomaly. The pressure measurements have been stable and coherent since the change. The cryogenics worked well, and the cool-down went quite smoothly, without any particular difficulty. The automated start of the turbines had to be fine-tuned to get a smooth transition, as it was observed that the cooling power delivered by the turbines was slightly higher than needed, causing the cold box to stop automatically. This had no consequence as the cold box safety system acts to keep ...

  7. Rates of change of the earth's magnetic field measured by recent analyses

    Science.gov (United States)

    Harrison, C. G. A.; Huang, Qilin

    1990-01-01

    Typical rates of change of the earth's magnetic field are presented as a function of the earth's spherical harmonics. Harmonics up to the eight degree are analyzed. With the increase in the degree of the harmonics an increase in the relative rate of change can be observed. For higher degrees, the rate of change can be predicted. This enables a differentiation between harmonics originating in the core and harmonics caused by crustal magnetization. The westward drift of the magnetic field depends on the longitudinal gradient of the field. In order to determine the longitudinal motions, harmonics up to degree 20 can be utilized. The average rate of secular acceleration increases with the degree of harmonics from 0.001 deg/sq yr for a dipole term to an average of 0.05 deg/sq yr for degree eight harmonics.

  8. Automatic change detection in RapidEye data using the combined MAD and kernel MAF methods

    DEFF Research Database (Denmark)

    Nielsen, Allan Aasbjerg; Hecheltjen, Antje; Thonfeld, Frank

    2010-01-01

    The IR-MAD components show changes for a large part of the entire subset. Especially phenological changes in the agricultural fields surrounding the open pit are predominant. As opposed to this, kMAF components focus more on changes in the open-cast mine (and changes due to the two clouds...... and their shadows, not visible in the zoom). Ground data were available from bucket-wheel excavators on the extraction side (to the northwest in the open pit) in terms of elevation data for both dates. No ground data were available for changes due to backfill (southeastern part of the open pit) or changes due...

  9. Magnetic-property changes in epitaxial metal-film sandwiches

    International Nuclear Information System (INIS)

    Brodsky, M.B.

    1982-08-01

    Epitaxial metal-film sandwiches (EMFS) containing Pd or Cr, have been prepared between single-crystal Ag or Au. The modified Pd/Cr show major changes in physical properties. Pd has a stretched lattice parameter in Au-Pd-Au, which combines with a tetragonal distortion to cause exchange enhancements up to 28,000 and spin-fluctuation temperatures of 1 to 10 K. In Au-Cr-Au, Cr takes up the fcc structure, leading to superconductivity due to a high N(E/sub F/). These results are contrasted to data for Ag-Pd-Ag and Ag-Cr-Ag EMFS

  10. Rapidly changing treatment options adding burden to the management of typhoid fever

    Directory of Open Access Journals (Sweden)

    Jaspal Kaur

    2015-01-01

    Full Text Available Typhoid fever continues to be a global public health problem. It is caused by the facultative intracellular organisms Salmonella enteric serotype Typhi and Salmonella paratyphi. Antimicrobial therapy is the mainstay for treatment of typhoid fever. Chloramphenicol, ampicillin, and cotrimoxazole had been in use for decades for treating enteric fever. But the emergence and rapid spread of drug resistance has resulted in rapid shift of treatment options from chloramphenicol to fluoroquinolones to third generation cephalosporins to azithromycin with tigecycline and carbapenems in line, thus adding burden to the health-care sector in developing countries. Rational and judicious antibiotic prescribing practices by health professionals are necessary to prevent further development of drug resistance and help in re-emergence of sensitive strains.

  11. Methoxychlor and Vinclozolin Induce Rapid Changes in Intercellular and Intracellular Signaling in Liver Progenitor Cells.

    Science.gov (United States)

    Babica, Pavel; Zurabian, Rimma; Kumar, Esha R; Chopra, Rajus; Mianecki, Maxwell J; Park, Joon-Suk; Jaša, Libor; Trosko, James E; Upham, Brad L

    2016-09-01

    Methoxychlor (MXC) and vinclozolin (VIN) are well-recognized endocrine disrupting chemicals known to alter epigenetic regulations and transgenerational inheritance; however, non-endocrine disruption endpoints are also important. Thus, we determined the effects of MXC and VIN on the dysregulation of gap junctional intercellular communication (GJIC) and activation of mitogen-activated protein kinases (MAPKs) in WB-F344 rat liver epithelial cells. Both chemicals induced a rapid dysregulation of GJIC at non-cytotoxic doses, with 30 min EC50 values for GJIC inhibition being 10 µM for MXC and 126 µM for VIN. MXC inhibited GJIC for at least 24 h, while VIN effects were transient and GJIC recovered after 4 h. VIN induced rapid hyperphosphorylation and internalization of gap junction protein connexin43, and both chemicals also activated MAPK ERK1/2 and p38. Effects on GJIC were not prevented by MEK1/2 inhibitor, but by an inhibitor of phosphatidylcholine-specific phospholipase C (PC-PLC), resveratrol, and in the case of VIN, also, by a p38 inhibitor. Estrogen (ER) and androgen receptor (AR) modulators (estradiol, ICI 182,780, HPTE, testosterone, flutamide, VIN M2) did not attenuate MXC or VIN effects on GJIC. Our data also indicate that the effects were elicited by the parental compounds of MXC and VIN. Our study provides new evidence that MXC and VIN dysregulate GJIC via mechanisms involving rapid activation of PC-PLC occurring independently of ER- or AR-dependent genomic signaling. Such alterations of rapid intercellular and intracellular signaling events involved in regulations of gene expression, tissue development, function and homeostasis, could also contribute to transgenerational epigenetic effects of endocrine disruptors. © The Author 2016. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  12. Transient flows in rectangular MHD ducts under the influence of suddenly changing applied magnetic fields

    International Nuclear Information System (INIS)

    Kobayashi, Junichi

    1979-01-01

    The study on the transient flow characteristics in MHD ducts under orthogonal magnetic field is divided into handling two problems: the problem of changing pressure gradient in a uniform orthogonal magnetic field and the problem in which the orthogonal magnetic field itself changes with time. The former has been investigated by many persons, but the latter has not been investigated so often as the former because of its difficulty of handling. In addition, if it is intended to grasp properly the transient flow characteristics in actual MHD ducts, it will be also important that the effects of the electric conductivity of side walls and aspect ratio are clarified. In other words, this paper deals with the problem in which a uniform orthogonal magnetic field is suddenly applied in such manner as Heaviside's step function to or removed from the conductive fluids flowing in sufficiently long rectangular MHD ducts. First, the MHD fundamental equations are described, then they are normalized to give boundary conditions and initial conditions. Next, the transient flow and the derived magnetic field characteristics are numerically analyzed by the difference calculus, and thus the effects of conductor, insulated wall, aspect ratio, Hartmann number, magnetic Prandtl number and others on the above characteristics are clarified. (Wakatsuki, Y.)

  13. Land use change monitoring in Maryland using a probabilistic sample and rapid photointerpretation

    Science.gov (United States)

    Tonya Lister; Andrew Lister; Eunice Alexander

    2014-01-01

    The U.S. state of Maryland needs to monitor land use change in order to address land management objectives. This paper presents a change detection method that, through automation and standard geographic information system (GIS) techniques, facilitates the estimation of landscape change via photointerpretation. Using the protocols developed, we show a net loss of forest...

  14. Rapid lung MRI in children with pulmonary infections: Time to change our diagnostic algorithms.

    Science.gov (United States)

    Sodhi, Kushaljit Singh; Khandelwal, Niranjan; Saxena, Akshay Kumar; Singh, Meenu; Agarwal, Ritesh; Bhatia, Anmol; Lee, Edward Y

    2016-05-01

    To determine the diagnostic utility of a new rapid MRI protocol, as compared with computed tomography (CT) for the detection of various pulmonary and mediastinal abnormalities in children with suspected pulmonary infections. Seventy-five children (age range of 5 to 15 years) with clinically suspected pulmonary infections were enrolled in this prospective study, which was approved by the institutional ethics committee. All patients underwent thoracic MRI (1.5T) and CT (64 detector) scan within 48 h of each other. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of MRI were evaluated with CT as a standard of reference. Inter-observer agreement was measured with the kappa coefficient. MRI with a new rapid MRI protocol demonstrated sensitivity, specificity, PPV, and NPV of 100% for detecting pulmonary consolidation, nodules (>3 mm), cyst/cavity, hyperinflation, pleural effusion, and lymph nodes. The kappa-test showed almost perfect agreement between MRI and multidetector CT (MDCT) in detecting thoracic abnormalities (k = 0.9). No statistically significant difference was observed between MRI and MDCT for detecting thoracic abnormalities by the McNemar test (P = 0.125). Rapid lung MRI was found to be comparable to MDCT for detecting thoracic abnormalities in pediatric patients with clinically suspected pulmonary infections. It has a great potential as the first line cross-sectional imaging modality of choice in this patient population. However, further studies will be helpful for confirmation of our findings. © 2015 Wiley Periodicals, Inc.

  15. Observation and analysis of abrupt changes in the interplanetary plasma velocity and magnetic field.

    Science.gov (United States)

    Martin, R. N.; Belcher, J. W.; Lazarus, A. J.

    1973-01-01

    This paper presents a limited study of the physical nature of abrupt changes in the interplanetary plasma velocity and magnetic field based on 19 day's data from the Pioneer 6 spacecraft. The period was chosen to include a high-velocity solar wind stream and low-velocity wind. Abrupt events were accepted for study if the sum of the energy density in the magnetic field and velocity changes was above a specified minimum. A statistical analysis of the events in the high-velocity solar wind stream shows that Alfvenic changes predominate. This conclusion is independent of whether steady state requirements are imposed on conditions before and after the event. Alfvenic changes do not dominate in the lower-speed wind. This study extends the plasma field evidence for outwardly propagating Alfvenic changes to time scales as small as 1 min (scale lengths on the order of 20,000 km).

  16. A replicated climate change field experiment reveals rapid evolutionary response in an ecologically important soil invertebrate

    DEFF Research Database (Denmark)

    Bataillon, Thomas; Galtier, Nicolas; Bernard, Aurelien

    2016-01-01

    to climate change in a common annelid worm using a controlled replicated experiment where climatic conditions were manipulated in a natural setting. Analyzing the transcribed genome of 15 local populations, we found that about 12% of the genetic polymorphisms exhibit differences in allele frequencies......Whether species can respond evolutionarily to current climate change is crucial for the persistence of many species. Yet, very few studies have examined genetic responses to climate change in manipulated experiments carried out innatural field conditions. We examined the evolutionary response...... associated to changes in soil temperature and soil moisture. This shows an evolutionaryresponse to realistic climate change happening over short-time scale, and calls for incorporating evolution into modelspredicting future response of species to climate change. It also shows that designed climate change...

  17. Origin and Evolution of Magnetic Field in PMS Stars: Influence of Rotation and Structural Changes

    Energy Technology Data Exchange (ETDEWEB)

    Emeriau-Viard, Constance; Brun, Allan Sacha, E-mail: constance.emeriau@cea.fr, E-mail: sacha.brun@cea.fr [Laboratoire AIM Paris-Saclay CEA/DSM—CNRS—Université Paris Diderot, IRFU/DAp CEA Paris-Saclay, F-91191 Gif-sur-Yvette Cedex (France)

    2017-09-01

    During stellar evolution, especially in the pre-main-sequence phase, stellar structure and rotation evolve significantly, causing major changes in the dynamics and global flows of the star. We wish to assess the consequences of these changes on stellar dynamo, internal magnetic field topology, and activity level. To do so, we have performed a series of 3D HD and MHD simulations with the ASH code. We choose five different models characterized by the radius of their radiative zone following an evolutionary track computed by a 1D stellar evolution code. These models characterized stellar evolution from 1 to 50 Myr. By introducing a seed magnetic field in the fully convective model and spreading its evolved state through all four remaining cases, we observe systematic variations in the dynamical properties and magnetic field amplitude and topology of the models. The five MHD simulations develop a strong dynamo field that can reach an equipartition state between the kinetic and magnetic energies and even superequipartition levels in the faster-rotating cases. We find that the magnetic field amplitude increases as it evolves toward the zero-age main sequence. Moreover, the magnetic field topology becomes more complex, with a decreasing axisymmetric component and a nonaxisymmetric one becoming predominant. The dipolar components decrease as the rotation rate and the size of the radiative core increase. The magnetic fields possess a mixed poloidal-toroidal topology with no obvious dominant component. Moreover, the relaxation of the vestige dynamo magnetic field within the radiative core is found to satisfy MHD stability criteria. Hence, it does not experience a global reconfiguration but slowly relaxes by retaining its mixed stable poloidal-toroidal topology.

  18. Changes of microstructure and magnetic properties of Nd-Fe-B sintered magnets by doping Al-Cu

    International Nuclear Information System (INIS)

    Ni Junjie; Ma Tianyu; Yan Mi

    2011-01-01

    The microstructural and magnetic properties of Al 100-x Cu x (15at%≤x≤45 at%) doped Nd-Fe-B magnets were studied. The distribution and alloying effects of Cu or Al on the intergranular microstructure were investigated by thermodynamic analysis, differential scanning calorimetery and microscopy techniques. It was observed that when the Cu content of Al 100x Cu x exceeds to 25 at%, the (Pr, Nd)Cu and CuAl 2 phases form in these magnets. The formation of (Pr, Nd)Cu phase depends on the negative formation enthalpy of (Pr, Nd)Cu and the exclusive distribution of Cu in the intergranular regions. The eutectic reaction between (Pr, Nd)Cu phase and (Pr, Nd) occurs at 480 deg. C, which forms the liquid phase that dissolves the (Pr, Nd) 2 Fe 14 B surface irregularities and thus increases the quantities of (Pr, Nd)-rich phase at the grain boundaries. These changes benefit the grain boundary microstructure, especially the distribution of (Pr, Nd)-rich phase, which effectively improves the intrinsic coercivity i H c due to the decreases of exchange coupling between the (Pr, Nd) 2 Fe 14 B grains. - Highlights: → Cu/Al effects on Nd-Fe-B structure depend on their distribution/alloying behaviors. → Cu exclusively distributes in grain boundaries different from Al and has negative mixing heat with Nd. → (Pr,Nd)Cu phase besides CuAl 2 forms in grain boundaries with Cu content increase. → (Pr,Nd)Cu phases optimize microstructure and increase magnetic properties.

  19. Analytical description of changes in the magnetic states of chromium-nickel steel under uniaxial elastic deformation

    Science.gov (United States)

    Gorkunov, E. S.; Yakushenko, E. I.; Zadvorkin, S. M.; Mushnikov, A. N.

    2017-12-01

    Dependences of magnetization and magnetic permeability of the 15KhN4D structural steel on the value of uniaxial stresses and magnetic field strength are obtained. A polynomial approximation fairly accurately describing the observed changes is proposed on the basis of experimental data.

  20. Rapid change in the defense of flightless young by a mourning dove parent

    Science.gov (United States)

    Berdeen, James; Otis, D.L.

    2011-01-01

    We report that an adult-sized Zenaida macroura (Mourning Dove), presumably a parent, rapidly decreased risk taken in defense of a juvenile as the likelihood of predation to the juvenile increased. We attribute this decrease in risk taken to (1) the parent's perception that the risk of predation had increased to the extent that a continuation of defensive behaviors would not prevent the death of the juvenile, and (2) its attempt to minimize its own risk of death. It may be that there is a threshold beyond which Mourning Dove parents will forgo the risk of additional defense of offspring in favor of making another reproductive attempt.

  1. Operational research leading to rapid national policy change: tuberculosis-diabetes collaboration in India.

    Science.gov (United States)

    Kumar, A M V; Satyanarayana, S; Wilson, N C; Chadha, S S; Gupta, D; Nair, S; Zachariah, R; Kapur, A; Harries, A D

    2014-06-21

    In 2011, bi-directional screening for tuberculosis (TB) and diabetes mellitus (DM) was recommended by the World Health Organization (WHO), although how best to implement the activity was not clear. In India, with early engagement of national programme managers and all important stakeholders, a countrywide, multicentre operational research (OR) project was designed in October 2011 and completed in 2012. The results led to a rapid national policy decision to routinely screen all TB patients for DM in September 2012. The process, experience and enablers of implementing this unique and successful collaborative model of operational research are presented.

  2. Study on microstructure of corpus striatum in patients with idiopathic rapid eye movement sleep behavior disorder using magnetic resonance imaging

    Directory of Open Access Journals (Sweden)

    Ya-meng ZHANG

    2017-07-01

    Full Text Available Objective To investigate the structure of corpus striatum and the integrity of white matter fiber in patients with Parkinson's disease (PD and idiopathic rapid eye movement sleep behavior disorder (iRBD.  Methods Twelve patients with iRBD, 12 patients with PD and 10 healthy subjects that were well matched in gender, age and education were enrolled in this study. Head MRI examination was performed to all subjects to observe the changes of corpus striatum structure (the gray matter volume and the integrity of white matter fiber [fractional anisotropy (FA] by combining voxel?based morphometry (VBM and diffusion tensor imaging (DTI.  Results Compared with healthy subjects, the gray matter volume of left caudate nucleus was significantly decreased (P < 0.005, and FA values of left caudate nucleus (P < 0.005, right caudate nucleus (P < 0.001 and right putamen (P < 0.05 were all significantly reduced in iRBD patients; FA value of right putamen was significantly decreased in PD patients (P < 0.05. Compared with PD patients, the gray matter volume of left caudate nucleus of iRBD patients was significantly reduced (P < 0.001, FA values of left caudate nucleus (P < 0.01 and right caudate nucleus (P < 0.005 of iRBD patients were significantly reduced.  Conclusions There is atrophy of gray matter volume and extensive white matter fiber impairment in corpus striatum of patients with iRBD, and the white matter fiber impairment was similar to PD, which provides an anatomical evidence for iRBD being presymptom of PD. DOI: 10.3969/j.issn.1672-6731.2017.05.008

  3. Rapid and reagent-saving immunoassay using innovative stirring actions of magnetic beads in microreactors in the sequential injection mode.

    Science.gov (United States)

    Tanaka, K; Imagawa, H

    2005-12-15

    We developed new ELISA techniques in sequential injection analysis (SIA) mode using microreactors with content of a few microliters. We immobilized antibodies on magnetic beads 1.0mum in diameter, injected the beads into microreactors and applied rotating magnetic fields of several hundred gauss. Magnetic beads, suspended in liquid in density of approximately 10(9)-10(10) particles per millilitre, form a large number of thin rod clusters, whose length-wise axes are oriented in parallel with the magnetic field. We rotate the Nd magnets below the center of the microreactor by a tiny motor at about 2000-5000rpm. These rotating clusters remarkably accelerate the binding rate of the antibodies with antigens in the liquid. The beads are trapped around the center of the rotating magnetic field even in the flowing liquid. This newly found phenomenon enables easy bead handling in microreactors. Modification of reactor walls with selected blocking reagents was essential, because protein-coated beads often stick to the wall surface and cannot move freely. Washing steps were also shortened.

  4. Detection of undistorted continuous wave (CW) electron paramagnetic resonance (EPR) spectra with non-adiabatic rapid sweep (NARS) of the magnetic field

    Science.gov (United States)

    Kittell, Aaron W.; Camenisch, Theodore G.; Ratke, Joseph J.; Sidabras, Jason W.; Hyde, James S.

    2011-01-01

    A continuous wave (CW) electron paramagnetic resonance (EPR) spectrum is typically displayed as the first harmonic response to the application of 100 kHz magnetic field modulation, which is used to enhance sensitivity by reducing the level of 1/f noise. However, magnetic field modulation of any amplitude causes spectral broadening and sacrifices EPR spectral intensity by at least a factor of two. In the work presented here, a CW rapid-scan spectroscopic technique that avoids these compromises and also provides a means of avoiding 1/f noise is developed. This technique, termed non-adiabatic rapid sweep (NARS) EPR, consists of repetitively sweeping the polarizing magnetic field in a linear manner over a spectral fragment with a small coil at a repetition rate that is sufficiently high that receiver noise, microwave phase noise, and environmental microphonics, each of which has 1/f characteristics, are overcome. Nevertheless, the rate of sweep is sufficiently slow that adiabatic responses are avoided and the spin system is always close to thermal equilibrium. The repetitively acquired spectra from the spectral fragment are averaged. Under these conditions, undistorted pure absorption spectra are obtained without broadening or loss of signal intensity. A digital filter such as a moving average is applied to remove high frequency noise, which is approximately equivalent in bandwidth to use of an integrating time constant in conventional field modulation with lock-in detection. Nitroxide spectra at L- and X-band are presented. PMID:21741868

  5. APTES Functionalized Iron Oxide-Silver Magnetic Hetero-Nanocomposites for Selective Capture and Rapid Removal of Salmonella enteritidis from Aqueous Solution

    Science.gov (United States)

    Trang, Vu Thi; Dinh, Ngo Xuan; Lan, Hoang; Tam, Le Thi; Huy, Tran Quang; Tuan, Pham Anh; Phan, Vu Ngoc; Le, Anh-Tuan

    2018-02-01

    Magnetic nanomaterials, as a promising platform for the fast and sensitive detection of bacterial pathogens, have attracted increasing interest from researchers in recent years. In this work, by utilizing a two-step synthetic technique consisting of co-precipitation and subsequent hydrothermal reaction, followed by functionalization steps with (3-aminopropyl)triethoxysilane (APTES) and the antibody against Salmonella enteritidis, antibody-conjugated Fe3O4-Ag@APTES hetero-nanocomposites were successfully prepared. Due to the specific antibody, the developed Fe3O4-Ag@APTES@SE-Ab conjugates are capable of selectively capturing S. enteritidis at a low concentration of about 101 CFU/mL. Moreover, the prepared magnetic conjugates also revealed that the S. enteritidis could be rapidly removed from water solution in 20 min by using an external magnetic field with a removal efficiency obtained of ˜ 91.36%. These results indicated that the Fe3O4-Ag@APTES@SE-Ab conjugates are promising for the rapid selective capture and removal of bacterial pathogens from aqueous environments, and can be used for improving the detection quality of pathogens in water samples using immunosensor-based diagnostic tests.

  6. Magnetic Fe3O4@TiO2 Nanoparticles-based Test Strip Immunosensing Device for Rapid Detection of Phosphorylated Butyrylcholinesterase

    Energy Technology Data Exchange (ETDEWEB)

    Ge, Xiaoxiao; Zhang, Weiying; Lin, Yuehe; Du, Dan

    2013-12-15

    An integrated magnetic nanoparticles-based test-strip immunosensing device was developed for rapid and sensitive quantification of phosphorylated butyrylcholinesterase (BChE), the biomarker of exposure to organophosphous pesticides (OP), in human plasma. In order to overcome the difficulty in scarce availability of OP-specific antibody, here magnetic Fe3O4@TiO2 nanoparticles were used and adsorbed on the test strip through a small magnet inserted in the device to capture target OP-BChE through selective binding between TiO2 and OP moiety. Further recognition was completed by horseradish peroxidase (HRP) and anti-BChE antibody (Ab) co-immobilized gold nanoparticles (GNPs). Their strong affinities among Fe3O4@TiO2, OP-BChE and HRP/Ab-GNPs were characterized by quartz crystal microbalance (QCM), surface plasmon resonance (SPR) and square wave voltammetry (SWV) measurements. After cutting off from test strip, the resulted immunocomplex (HRP/Ab-GNPs/OP-BChE/Fe3O4@TiO2) was measured by SWV using a screen printed electrode under the test zone. Greatly enhanced sensitivity was achieved by introduction of GNPs to link enzyme and antibody at high ratio, which amplifies electrocatalytic signal significantly. Moreover, the use of test strip for fast immunoreactions reduces analytical time remarkably. Coupling with a portable electrochemical detector, the integrated device with advanced nanotechnology displays great promise for sensitive, rapid and in-filed on-site evaluation of OP poisoning.

  7. Rapid forest change in the interior west presents analysis opportunities and challenges

    Science.gov (United States)

    John D. Shaw

    2007-01-01

    A recent drought has caused compositional and structural changes in Interior West forests. Recent periodic and annual inventory data provide an opportunity to analyze forest changes on a grand scale. This "natural experiment" also provides opportunities to test the effectiveness of Forest Inventory and Analysis (FIA) methodologies. It also presents some...

  8. A rapid infusion protocol is safe for total dose iron polymaltose: time for change.

    Science.gov (United States)

    Garg, M; Morrison, G; Friedman, A; Lau, A; Lau, D; Gibson, P R

    2011-07-01

    Intravenous correction of iron deficiency by total dose iron polymaltose is inexpensive and safe, but current protocols entail prolonged administration over more than 4 h. This results in reduced patient acceptance, and hospital resource strain. We aimed to assess prospectively the safety of a rapid intravenous protocol and compare this with historical controls. Consecutive patients in whom intravenous iron replacement was indicated were invited to have up to 1.5 g iron polymaltose by a 58-min infusion protocol after an initial 15-min test dose without pre-medication. Infusion-related adverse events (AE) and delayed AE over the ensuing 5 days were also prospectively documented and graded as mild, moderate or severe. One hundred patients, 63 female, mean age 54 (range 18-85) years were studied. Thirty-four infusion-related AE to iron polymaltose occurred in a total of 24 patients--25 mild, 8 moderate and 1 severe; higher than previously reported for a slow protocol iron infusion. Thirty-one delayed AE occurred in 26 patients--26 mild, 3 moderate and 2 severe; similar to previously reported. All but five patients reported they would prefer iron replacement through the rapid protocol again. The presence of inflammatory bowel disease (IBD) predicted infusion-related reactions (54% vs 14% without IBD, P cost, resource utilization and time benefits for the patient and hospital system. © 2011 The Authors. Internal Medicine Journal © 2011 Royal Australasian College of Physicians.

  9. Rapid transformation of two libraries using Kotter's Eight Steps of Change.

    Science.gov (United States)

    Wheeler, Terrie R; Holmes, Kristi L

    2017-07-01

    Two new directors were each charged by their institutions to catalyze transformational change in their libraries and to develop dynamic and evolving information ecosystems ready for the information challenges of the future. The directors approached this transformational change using a strategic, forward-looking approach. This paper presents examples of actions that served as catalysts for change at the two libraries using Kotter's Eight Steps of Change as a framework. Small and large changes are critical for successfully transforming library services, resources, and personnel. Libraries are faced with incredible pressure to adapt to meet emerging and intensifying information needs on today's academic medical campuses. These pressures offer an opportunity for libraries to accelerate their evolution at the micro and macro levels. This commentary reports the expansion of new services and areas of support, enhancement of professional visibility of the libraries on their campuses, and overall, a more positive and productive environment at the respective institutions.

  10. Systemic range shift lags among a pollinator species assemblage following rapid climate change

    DEFF Research Database (Denmark)

    Bedford, Felicity E.; Whittaker, Robert J.; Kerr, Jeremy T.

    2012-01-01

    Contemporary climate change is driving widespread geographical range shifts among many species. If species are tracking changing climate successfully, then leading populations should experience similar climatic conditions through time as new populations establish beyond historical range margins....... Here, we investigate geographical range shifts relative to changing climatic conditions among a particularly well-sampled assemblage of butterflies in Canada. We assembled observations of 81 species and measured their latitudinal displacement between two periods: 1960–1975 (a period of little climate...... change) and 1990–2005 (a period with large climate change). We find an unexpected trend for species’ northern borders to shift progressively less relative to increasing minimum winter temperatures in northern Canada. This study demonstrates a novel, systemic latitudinal gradient in lags among a large...

  11. Influences of sex and activity level on physiological changes in individual adult sockeye salmon during rapid senescence.

    Science.gov (United States)

    Hruska, Kimberly A; Hinch, Scott G; Healey, Michael C; Patterson, David A; Larsson, Stefan; Farrell, Anthony P

    2010-01-01

    A noninvasive biopsy protocol was used to sample plasma and gill tissue in individual sockeye salmon (Oncorhynchus nerka) during the critical life stage associated with spawning-arrival at a spawning channel through senescence to death several days later. Our main objective was to characterize the physiological changes associated with rapid senescence in terms of the physiological stress/cortisol hypersecretion model and the energy exhaustion model. Salmon lived an average of 5 d in the spawning channel, during which time there were three major physiological trends that were independent of sexual status: a large increase in plasma indicators of stress and exercise (i.e., lactate and cortisol), a decrease in the major plasma ions (i.e., Cl(-) and Na(+)) and osmolality, and a decrease in gross somatic energy reserves. Contrary to a generalized stress response, plasma glucose decreased in approximately 2/3 of the fish after arrival, as opposed to increasing. Furthermore, plasma cortisol levels at spawning-ground arrival were not correlated with the degree of ionoregulatory changes during rapid senescence. One mechanism of mortality in some fish may involve the exhaustion of energy reserves, resulting in the inability to mobilize plasma glucose. Sex had a significant modulating effect on the degree of physiological change. Females exhibited a greater magnitude of change for gross somatic energy, osmolality, and plasma concentrations of Cl(-), Na(+), cortisol, testosterone, 11-ketotestosterone, 17,20beta-progesterone, and estradiol. The activity level of an individual on the spawning grounds appeared to influence the degree of some physiological changes during senescence. For example, males that received a greater frequency of attacks exhibited larger net decreases in plasma 11-ketotestosterone while on the spawning grounds. These results suggest that rapid senescence on spawning grounds is influenced by multiple physiological processes and perhaps behavior. This study

  12. Changes in basal ganglia processing of cortical input following magnetic stimulation in Parkinsonism.

    Science.gov (United States)

    Tischler, Hadass; Moran, Anan; Belelovsky, Katya; Bronfeld, Maya; Korngreen, Alon; Bar-Gad, Izhar

    2012-12-01

    Parkinsonism is associated with major changes in neuronal activity throughout the cortico-basal ganglia loop. Current measures quantify changes in baseline neuronal and network activity but do not capture alterations in information propagation throughout the system. Here, we applied a novel non-invasive magnetic stimulation approach using a custom-made mini-coil that enabled us to study transmission of neuronal activity throughout the cortico-basal ganglia loop in both normal and parkinsonian primates. By magnetically perturbing cortical activity while simultaneously recording neuronal responses along the cortico-basal ganglia loop, we were able to directly investigate modifications in descending cortical activity transmission. We found that in both the normal and parkinsonian states, cortical neurons displayed similar multi-phase firing rate modulations in response to magnetic stimulation. However, in the basal ganglia, large synaptically driven stereotypic neuronal modulation was present in the parkinsonian state that was mostly absent in the normal state. The stimulation-induced neuronal activity pattern highlights the change in information propagation along the cortico-basal ganglia loop. Our findings thus point to the role of abnormal dynamic activity transmission rather than changes in baseline activity as a major component in parkinsonian pathophysiology. Moreover, our results hint that the application of transcranial magnetic stimulation (TMS) in human patients of different disorders may result in different neuronal effects than the one induced in normal subjects. Copyright © 2012 Elsevier Inc. All rights reserved.

  13. Tumor microvascular changes in antiangiogenic treatment : Assessment by magnetic resonance contrast media of different molecular weights

    NARCIS (Netherlands)

    Turetschek, K; Preda, A; Novikov, [No Value; Brasch, RC; Weinmann, HJ; Wunderbaldinger, P; Roberts, TPL

    Purpose: To test magnetic resonance (MR) contrast media of different molecular weights (MWs) for their potential to characterize noninvasively microvascular changes in an experimental tumor treatment model. Materials and Methods: MD-MBA-435, a poorly differentiated human breast cancer cell line, was

  14. Visualizing Nanocatalysts in Action from Color Change Reaction to Magnetic Recycling and Reuse

    Science.gov (United States)

    Hudson, Reuben; Bishop, Alexandra; Glaisher, Samuel; Katz, Jeffrey L.

    2015-01-01

    A demonstration to highlight the utility and ease of handling environmentally benign magnetically recoverable nanoparticle catalysts is described. The demonstration offers two powerful visuals. The first is a color change oxidation of tetramethylbenzidine by hydrogen peroxide catalyzed by Fe[subscript 3]O[subscript 4] nanoparticles. The second,…

  15. Structural Changes in Deformed Soft Magnetic Ni-Based Metallic Glass

    NARCIS (Netherlands)

    Jurikova, A.; Csach, K.; Miskuf, J.; Ocelik, V.

    The effects of intensive plastic deformation of the soft magnetic metallic glass Ni Si 13 on the structural relaxation were examined. The enthalpy changes studied by differential scanning calorimetry revealed that the intensive plastic deformation was associated with the partial structural

  16. Effect of Hf underlayer on structure and magnetic properties of rapid thermal annealed FePt thin films

    International Nuclear Information System (INIS)

    Shen, C.Y.; Yuan, F.T.; Chang, H.W.; Lin, M.C.; Su, C.C.; Chang, S.T.; Wang, C.R.; Mei, J.K.; Hsiao, S.N.; Chen, C.C.; Shih, C.W.; Chang, W.C.

    2014-01-01

    FePt(20 nm) and FePt(20 nm)/Hf(10 nm) thin films prepared on the glass substrates by sputtering and post annealing are studied. For both samples, the as deposited films are disordered and L1 0 -ordering is triggered by a 400 °C-annealing. At T a ≥600 °C, Hf–Pt intermetallic compound forms with increasing T a , which consumes Pt in FePt layer and results in the formation of Fe 3 Pt phase. The film becomes soft magnetic at T a =800 °C. The optimized condition of FePt/Hf film is in the T a range of 500 to 600 °C where the interdiffusion between Hf and FePt layer is not extensive. The value of H c is 8.9 kOe and M r is 650–670 emu/cm 3 . Unlike FePt films, the Hf-undelayered samples show significantly reduced out-of-plane remanent and coercivity. The values for both are around 50% smaller than that of the FePt films. Additionally, Hf underlayer markedly reduces the FePt grain size and narrows the distribution, which enhances magnetic intergrain coupling. Good in-plane magnetic properties are preferred for the uses like a hard biasing magnet in a spintronic device. - Highlights: • Effect of Hf underlayer on structure and magnetic properties of FePt films are studied. • Hf underlayer reduces size, narrows the distribution of grains and thus enhances intergrain coupling. • Higher T a ≥600 °C makes Hf–Pt intermetallic compound and thus Fe 3 Pt phase form. • Good in-plane magnetic property is proper for uses in hard biasing magnet in spintronic devices

  17. Progress of magnetic resonance spectroscopy in chronic renal failure patients with vertebral bone change

    International Nuclear Information System (INIS)

    Gao Cailiang; Dong Guoli; Zeng Nanlin

    2013-01-01

    Bone changes caused by kidney diseases affect the quality of life in the patients with chronic renal failure. How to improve evaluation of the bone change, and consequently start early intervention and treatment is an important topic. Magnetic resonance spectroscopy (MRS) has been successfully used in the evaluations of central nervous system, breast and prostate, etc. Evaluation of bone changes with MRS is under studied. This article reviewed the MRS in evaluation of vertebral body bone changes in patients with chronic renal failure. (authors)

  18. Television, disordered eating, and young women in Fiji: negotiating body image and identity during rapid social change.

    Science.gov (United States)

    Becker, Anne E

    2004-12-01

    Although the relationship between media exposure and risk behavior among youth is established at a population level, the specific psychological and social mechanisms mediating the adverse effects of media on youth remain poorly understood. This study reports on an investigation of the impact of the introduction of television to a rural community in Western Fiji on adolescent ethnic Fijian girls in a setting of rapid social and economic change. Narrative data were collected from 30 purposively selected ethnic Fijian secondary school girls via semi-structured, open-ended interviews. Interviews were conducted in 1998, 3 years after television was first broadcast to this region of Fiji. Narrative data were analyzed for content relating to response to television and mechanisms that mediate self and body image in Fijian adolescents. Data in this sample suggest that media imagery is used in both creative and destructive ways by adolescent Fijian girls to navigate opportunities and conflicts posed by the rapidly changing social environment. Study respondents indicated their explicit modeling of the perceived positive attributes of characters presented in television dramas, but also the beginnings of weight and body shape preoccupation, purging behavior to control weight, and body disparagement. Response to television appeared to be shaped by a desire for competitive social positioning during a period of rapid social transition. Understanding vulnerability to images and values imported with media will be critical to preventing disordered eating and, potentially, other youth risk behaviors in this population, as well as other populations at risk.

  19. Methodology for benzodiazepine receptor binding assays at physiological temperature. Rapid change in equilibrium with falling temperature

    International Nuclear Information System (INIS)

    Dawson, R.M.

    1986-01-01

    Benzodiazepine receptors of rat cerebellum were assayed with [ 3 H]-labeled flunitrazepam at 37 0 C, and assays were terminated by filtration in a cold room according to one of three protocols: keeping each sample at 37 degrees C until ready for filtration, taking the batch of samples (30) into the cold room and filtering sequentially in the order 1-30, and taking the batch of 30 samples into the cold room and filtering sequentially in the order 30-1. the results for each protocol were substantially different from each other, indicating that rapid disruption of equilibrium occurred as the samples cooled in the cold room while waiting to be filtered. Positive or negative cooperativity of binding was apparent, and misleading effects of gamma-aminobutyric acid on the affinity of diazepam were observed, unless each sample was kept at 37 0 C until just prior to filtration

  20. Rapid estimation of the moment magnitude of large earthquake from static strain changes

    Science.gov (United States)

    Itaba, S.

    2014-12-01

    The 2011 off the Pacific coast of Tohoku earthquake, of moment magnitude (Mw) 9.0, occurred on March 11, 2011. Based on the seismic wave, the prompt report of the magnitude which the Japan Meteorological Agency announced just after earthquake occurrence was 7.9, and it was considerably smaller than an actual value. On the other hand, using nine borehole strainmeters of Geological Survey of Japan, AIST, we estimated a fault model with Mw 8.7 for the earthquake on the boundary between the Pacific and North American plates. This model can be estimated about seven minutes after the origin time, and five minute after wave arrival. In order to grasp the magnitude of a great earthquake earlier, several methods are now being suggested to reduce the earthquake disasters including tsunami (e.g., Ohta et al., 2012). Our simple method of using strain steps is one of the strong methods for rapid estimation of the magnitude of great earthquakes.

  1. A Phos-tag-based magnetic-bead method for rapid and selective separation of phosphorylated biomolecules.

    Science.gov (United States)

    Tsunehiro, Masaya; Meki, Yuma; Matsuoka, Kanako; Kinoshita-Kikuta, Emiko; Kinoshita, Eiji; Koike, Tohru

    2013-04-15

    A simple and efficient method based on magnetic-bead technology has been developed for the separation of phosphorylated and nonphosphorylated low-molecular-weight biomolecules, such as nucleotides, phosphorylated amino acids, or phosphopeptides. The phosphate-binding site on the bead is an alkoxide-bridged dinuclear zinc(II) complex with 1,3-bis(pyridin-2-ylmethylamino)propan-2-olate (Phos-tag), which is linked to a hydrophilic cross-linked agarose coating on a magnetic core particle. All steps for the phosphate-affinity separation are conducted in buffers of neutral pH with 50 μL of the magnetic beads in a 1.5-mL microtube. The entire separation protocol for phosphomonoester-type compounds, from addition to elution, requires less than 12 min per sample if the buffers and the zinc(II)-bound Phos-tag magnetic beads have been prepared in advance. The phosphate-affinity magnetic beads are reusable at least 15 times without a decrease in their phosphate-binding ability and they are stable for three months in propan-2-ol. Copyright © 2013 Elsevier B.V. All rights reserved.

  2. Rapid spread of complex change: a case study in inpatient palliative care

    Directory of Open Access Journals (Sweden)

    Filipski Marta I

    2009-12-01

    Full Text Available Abstract Background Based on positive findings from a randomized controlled trial, Kaiser Permanente's national executive leadership group set an expectation that all Kaiser Permanente and partner hospitals would implement a consultative model of interdisciplinary, inpatient-based palliative care (IPC. Within one year, the number of IPC consultations program-wide increased almost tenfold from baseline, and the number of teams nearly doubled. We report here results from a qualitative evaluation of the IPC initiative after a year of implementation; our purpose was to understand factors supporting or impeding the rapid and consistent spread of a complex program. Methods Quality improvement study using a case study design and qualitative analysis of in-depth semi-structured interviews with 36 national, regional, and local leaders. Results Compelling evidence of impacts on patient satisfaction and quality of care generated 'pull' among adopters, expressed as a remarkably high degree of conviction about the value of the model. Broad leadership agreement gave rise to sponsorship and support that permeated the organization. A robust social network promoted knowledge exchange and built on an existing network with a strong interest in palliative care. Resource constraints, pre-existing programs of a different model, and ambiguous accountability for implementation impeded spread. Conclusions A complex, hospital-based, interdisciplinary intervention in a large health care organization spread rapidly due to a synergy between organizational 'push' strategies and grassroots-level pull. The combination of push and pull may be especially important when the organizational context or the practice to be spread is complex.

  3. Examination of rapid phase change in copper wires to improve material models and understanding of burst

    Science.gov (United States)

    Olles, Joseph; Garasi, Christopher; Ball, J. Patrick

    2017-11-01

    Electrically-pulsed wires undergo multiple phase changes including a postulated metastable phase resulting in explosive wire growth. Simulations using the MHD approximation attempt to account for the governing physics, but lack the material properties (equations-of-state and electrical conductivity) to accurately predict the phase evolution of the exploding (bursting) wire. To explore the dynamics of an exploding copper wire (in water), we employ a digital micro-Schlieren streak photography technique. This imaging quantifies wire expansion and shock waves emitted from the wire during phase changes. Using differential voltage probes, a Rogowski coil, and timing fiducials, the phase change of the wire is aligned with electrical power and energy deposition. Time-correlated electrical diagnostics and imaging allow for detailed validation of MHD simulations, comparing observed phases with phase change details found in the material property descriptions. In addition to streak imaging, a long exposure image is taken to capture axial striations along the length of the wire. These images are used to compare with results from 3D MHD simulations which propose that these perturbations impact the rate of wire expansion and temporal change in phases. If successful, the experimental data will identify areas for improvement in the material property models, and modeling results will provide insight into the details of phase change in the wire with correlation to variations in the electrical signals.

  4. Rapid shifts in Atta cephalotes fungus-garden enzyme activity after a change in fungal substrate (Attini, Formicidae)

    DEFF Research Database (Denmark)

    Kooij, P W; Schiøtt, M; Boomsma, J J

    2011-01-01

    Fungus gardens of the basidiomycete Leucocoprinus gongylophorus sustain large colonies of leaf-cutting ants by degrading the plant material collected by the ants. Recent studies have shown that enzyme activity in these gardens is primarily targeted toward starch, proteins and the pectin matrix......, we measured the changes in enzyme activity after a controlled shift in fungal substrate offered to six laboratory colonies of Atta cephalotes. An ant diet consisting exclusively of grains of parboiled rice rapidly increased the activity of endo-proteinases and some of the pectinases attacking...... from the rice diet, relative to the leaf diet controls. Enzyme activity in the older, bottom sections of fungus gardens decreased, indicating a faster processing of the rice substrate compared to the leaf diet. These results suggest that leaf-cutting ant fungus gardens can rapidly adjust enzyme...

  5. A comparison of rapid-scanning X-ray fluorescence mapping and magnetic resonance imaging to localize brain iron distribution

    International Nuclear Information System (INIS)

    McCrea, Richard P.E.; Harder, Sheri L.; Martin, Melanie; Buist, Richard; Nichol, Helen

    2008-01-01

    The clinical diagnosis of many neurodegenerative disorders relies primarily or exclusively on observed behaviors rather than measurable physical tests. One of the hallmarks of Alzheimer disease (AD) is the presence of amyloid-containing plaques associated with deposits of iron, copper and/or zinc. Work in other laboratories has shown that iron-rich plaques can be seen in the mouse brain in vivo with magnetic resonance imaging (MRI) using a high-field strength magnet but this iron cannot be visualized in humans using clinical magnets. To improve the interpretation of MRI, we correlated iron accumulation visualized by X-ray fluorescence spectroscopy, an element-specific technique with T1, T2, and susceptibility weighted MR (SWI) in a mouse model of AD. We show that SWI best shows areas of increased iron accumulation when compared to standard sequences

  6. Human adaptation responses to a rapidly changing Arctic: A research context for building system resilience

    Science.gov (United States)

    Chapin, T.; Brinkman, T. J.

    2016-12-01

    Although human behavior accounts for more uncertainty in future trajectories in climate change than do biophysical processes, most climate-change research fails to include human actions in research design and implementation. This is well-illustrated in the Arctic. At the global scale, arctic processes strongly influence the strength of biophysical feedbacks between global human emissions and the rate of climate warming. However, most human actions in the arctic have little effect on these feedbacks, so research can contribute most effectively to reduction in arctic warming through improved understanding of the strength of arctic-global biophysical feedbacks, as in NASA's ABoVE program, and its effective communication to policy makers and the public. In contrast, at the local to regional scale within the arctic, human actions may influence the ecological and societal consequences of arctic warming, so research benefits from active stakeholder engagement in research design and implementation. Human communities and other stakeholders (government and NGOs) respond heterogeneously to socioeconomic and environmental change, so research that documents the range of historical and current adaptive responses to change provides insights on the resilience (flexibility of future options) of social-ecological processes in the arctic. Alaskan communities have attempted a range of adaptive responses to coastal erosion (e.g., seasonal migration, protection in place, relocation), wildfire (fire suppression to use of fire to manage wildlife habitat or landscape heterogeneity), declining sea ice (e.g., new hunting technology, sea ice observations and predictions), and changes in wildlife and fish availability (e.g., switch to harvest of alternative species, harvest times, or harvest locations). Research that draws on both traditional and western knowledge facilitates adaptation and predictions of the likely societal consequences of climate change in the Arctic. Effective inclusion of

  7. Development and validation of a novel algorithm based on the ECG magnet response for rapid identification of any unknown pacemaker.

    Science.gov (United States)

    Squara, Fabien; Chik, William W; Benhayon, Daniel; Maeda, Shingo; Latcu, Decebal Gabriel; Lacaze-Gadonneix, Jonathan; Tibi, Thierry; Thomas, Olivier; Cooper, Joshua M; Duthoit, Guillaume

    2014-08-01

    Pacemaker (PM) interrogation requires correct manufacturer identification. However, an unidentified PM is a frequent occurrence, requiring time-consuming steps to identify the device. The purpose of this study was to develop and validate a novel algorithm for PM manufacturer identification, using the ECG response to magnet application. Data on the magnet responses of all recent PM models (≤15 years) from the 5 major manufacturers were collected. An algorithm based on the ECG response to magnet application to identify the PM manufacturer was subsequently developed. Patients undergoing ECG during magnet application in various clinical situations were prospectively recruited in 7 centers. The algorithm was applied in the analysis of every ECG by a cardiologist blinded to PM information. A second blinded cardiologist analyzed a sample of randomly selected ECGs in order to assess the reproducibility of the results. A total of 250 ECGs were analyzed during magnet application. The algorithm led to the correct single manufacturer choice in 242 ECGs (96.8%), whereas 7 (2.8%) could only be narrowed to either 1 of 2 manufacturer possibilities. Only 2 (0.4%) incorrect manufacturer identifications occurred. The algorithm identified Medtronic and Sorin Group PMs with 100% sensitivity and specificity, Biotronik PMs with 100% sensitivity and 99.5% specificity, and St. Jude and Boston Scientific PMs with 92% sensitivity and 100% specificity. The results were reproducible between the 2 blinded cardiologists with 92% concordant findings. Unknown PM manufacturers can be accurately identified by analyzing the ECG magnet response using this newly developed algorithm. Copyright © 2014 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

  8. Implications of rapid environmental change for polar bear behavior and sociality

    Science.gov (United States)

    Atwood, Todd C.

    2017-01-01

    Historically, the Arctic sea ice has functioned as a structural barrier that has limited the nature and extent of interactions between humans and polar bears (Ursus maritimus). However, declining sea ice extent, brought about by global climate change, is increasing the potential for human-polar bear interactions. Loss of sea ice habitat is driving changes to both human and polar bear behavior—it is facilitating increases in human activities (e.g., offshore oil and gas exploration and extraction, trans-Arctic shipping, recreation), while also causing the displacement of bears from preferred foraging habitat (i.e., sea ice over biologically productive shallow) to land in some portions of their range. The end result of these changes is that polar bears are spending greater amounts of time in close proximity to people. Coexistence between humans and polar bears will require imposing mechanisms to manage further development, as well as mitigation strategies that reduce the burden to local communities.

  9. Unbounded boundaries and shifting baselines: Estuaries and coastal seas in a rapidly changing world

    Science.gov (United States)

    Little, S.; Spencer, K. L.; Schuttelaars, H. M.; Millward, G. E.; Elliott, M.

    2017-11-01

    This Special Issue of Estuarine, Coastal and Shelf Science presents contributions from ECSA 55; an international symposium organised by the Estuarine and Coastal Sciences Association (ECSA) and Elsevier on the broad theme of estuaries and coastal seas in times of intense change. The objectives of the SI are to synthesise, hypothesise and illustrate the impacts of global change on estuaries and coastal seas through learning lessons from the past, discussing the current and forecasting for the future. It is highlighted here that establishing impacts and assigning cause to the many pressures of global change is and will continue to be a formidable challenge in estuaries and coastal seas, due in part to: (1) their complexity and unbounded nature; (2) difficulties distinguishing between human-induced changes and natural variations and; (3) multiple pressures and effects. The contributing authors have explored a number of these issues over a range of disciplines. The complexity and connectivity of estuaries and coastal seas have been investigated through studies of physicochemical and ecological components, whilst the human imprint on the environment has been identified through a series of predictive, contemporary, historical and palaeo approaches. The impact of human activities has been shown to occur over a range of spatial and temporal scales, requiring the development of integrated management approaches. These 30 articles provide an important contribution to our understanding and assessment of the impacts of global change. The authors highlight methods for essential management/mitigation of the consequences of global change and provide a set of directions, ideas and observations for future work. These include the need to consider: (1) the cumulative, synergistic and antagonistic effects of multiple pressures; (2) the importance of unbounded boundaries and connectivity across the aquatic continuum; (3) the value of combining cross-disciplinary palaeo, contemporary and

  10. Rapid morphological changes and loss of collagen following experimental acute colonic obstruction

    DEFF Research Database (Denmark)

    Krarup, Peter-Martin; Rehn, Martin; Sand-Dejmek, Janna

    2013-01-01

    Anastomosis of an acutely obstructed colon is associated with an increased risk of dehiscence. In experimental models, acute obstruction decreases collagen in the colonic wall, but the time course and propagation along the colon of the biochemical changes are unknown. Furthermore, there is a pauc......Anastomosis of an acutely obstructed colon is associated with an increased risk of dehiscence. In experimental models, acute obstruction decreases collagen in the colonic wall, but the time course and propagation along the colon of the biochemical changes are unknown. Furthermore...

  11. Long-distance gene flow and adaptation of forest trees to rapid climate change

    Science.gov (United States)

    Kremer, Antoine; Ronce, Ophélie; Robledo-Arnuncio, Juan J; Guillaume, Frédéric; Bohrer, Gil; Nathan, Ran; Bridle, Jon R; Gomulkiewicz, Richard; Klein, Etienne K; Ritland, Kermit; Kuparinen, Anna; Gerber, Sophie; Schueler, Silvio

    2012-01-01

    Forest trees are the dominant species in many parts of the world and predicting how they might respond to climate change is a vital global concern. Trees are capable of long-distance gene flow, which can promote adaptive evolution in novel environments by increasing genetic variation for fitness. It is unclear, however, if this can compensate for maladaptive effects of gene flow and for the long-generation times of trees. We critically review data on the extent of long-distance gene flow and summarise theory that allows us to predict evolutionary responses of trees to climate change. Estimates of long-distance gene flow based both on direct observations and on genetic methods provide evidence that genes can move over spatial scales larger than habitat shifts predicted under climate change within one generation. Both theoretical and empirical data suggest that the positive effects of gene flow on adaptation may dominate in many instances. The balance of positive to negative consequences of gene flow may, however, differ for leading edge, core and rear sections of forest distributions. We propose future experimental and theoretical research that would better integrate dispersal biology with evolutionary quantitative genetics and improve predictions of tree responses to climate change. PMID:22372546

  12. Evolution and behavioural responses to human-induced rapid environmental change.

    Science.gov (United States)

    Sih, Andrew; Ferrari, Maud C O; Harris, David J

    2011-03-01

    Almost all organisms live in environments that have been altered, to some degree, by human activities. Because behaviour mediates interactions between an individual and its environment, the ability of organisms to behave appropriately under these new conditions is crucial for determining their immediate success or failure in these modified environments. While hundreds of species are suffering dramatically from these environmental changes, others, such as urbanized and pest species, are doing better than ever. Our goal is to provide insights into explaining such variation. We first summarize the responses of some species to novel situations, including novel risks and resources, habitat loss/fragmentation, pollutants and climate change. Using a sensory ecology approach, we present a mechanistic framework for predicting variation in behavioural responses to environmental change, drawing from models of decision-making processes and an understanding of the selective background against which they evolved. Where immediate behavioural responses are inadequate, learning or evolutionary adaptation may prove useful, although these mechanisms are also constrained by evolutionary history. Although predicting the responses of species to environmental change is difficult, we highlight the need for a better understanding of the role of evolutionary history in shaping individuals' responses to their environment and provide suggestion for future work.

  13. Are plant species able to keep pace with the rapidly changing climate?

    Directory of Open Access Journals (Sweden)

    Sarah Cunze

    Full Text Available Future climate change is predicted to advance faster than the postglacial warming. Migration may therefore become a key driver for future development of biodiversity and ecosystem functioning. For 140 European plant species we computed past range shifts since the last glacial maximum and future range shifts for a variety of Intergovernmental Panel on Climate Change (IPCC scenarios and global circulation models (GCMs. Range shift rates were estimated by means of species distribution modelling (SDM. With process-based seed dispersal models we estimated species-specific migration rates for 27 dispersal modes addressing dispersal by wind (anemochory for different wind conditions, as well as dispersal by mammals (dispersal on animal's coat - epizoochory and dispersal by animals after feeding and digestion - endozoochory considering different animal species. Our process-based modelled migration rates generally exceeded the postglacial range shift rates indicating that the process-based models we used are capable of predicting migration rates that are in accordance with realized past migration. For most of the considered species, the modelled migration rates were considerably lower than the expected future climate change induced range shift rates. This implies that most plant species will not entirely be able to follow future climate-change-induced range shifts due to dispersal limitation. Animals with large day- and home-ranges are highly important for achieving high migration rates for many plant species, whereas anemochory is relevant for only few species.

  14. Rapid pacing results in changes in atrial but not in ventricular refractoriness

    NARCIS (Netherlands)

    Schoonderwoerd, BA; Van Gelder, IC; Tieleman, RG; Bel, KJ; Crijns, HJGM

    It is well known that atrial tachycardia causes atrial electrical remodeling, characterized by shortening of atrial effective refractory periods (AERPs) and loss of physiological adaptation of AERP to rate. However, the nature and time course of changes in ventricular effective refractory periods

  15. Linguistic Mechanisms Cause Rapid Behavior Change. Part Two: How Linguistic Frames Affect Motivation

    Science.gov (United States)

    Yeager, Joseph; Sommer, Linda

    2007-01-01

    Written and spoken language contains inherent mechanisms driving motivation. Accessing and modifying psycholinguistic mechanisms, links language frames to changes in behavior within the context of motivational profiling. For example, holding an object like an imported apple feels safe until one is informed it was grown in a toxic waste dump.…

  16. Exposure science in an age of rapidly changing climate: challenges and opportunities

    Science.gov (United States)

    LaKind, Judy S; Overpeck, Jonathan; Breysse, Patrick N; Backer, Lorrie; Richardson, Susan D; Sobus, Jon; Sapkota, Amir; Upperman, Crystal R; Jiang, Chengsheng; Beard, C Ben; Brunkard, J M; Bell, Jesse E; Harris, Ryan; Chretien, Jean-Paul; Peltier, Richard E; Chew, Ginger L; Blount, Benjamin C

    2016-01-01

    Climate change is anticipated to alter the production, use, release, and fate of environmental chemicals, likely leading to increased uncertainty in exposure and human health risk predictions. Exposure science provides a key connection between changes in climate and associated health outcomes. The theme of the 2015 Annual Meeting of the International Society of Exposure Science—Exposures in an Evolving Environment—brought this issue to the fore. By directing attention to questions that may affect society in profound ways, exposure scientists have an opportunity to conduct “consequential science”—doing science that matters, using our tools for the greater good and to answer key policy questions, and identifying causes leading to implementation of solutions. Understanding the implications of changing exposures on public health may be one of the most consequential areas of study in which exposure scientists could currently be engaged. In this paper, we use a series of case studies to identify exposure data gaps and research paths that will enable us to capture the information necessary for understanding climate change-related human exposures and consequent health impacts. We hope that paper will focus attention on under-developed areas of exposure science that will likely have broad implications for public health. PMID:27485992

  17. Challenge and Response, Strategies for Survival in a Rapidly Changing Forest Products Industry

    Science.gov (United States)

    Al Schuler; Craig Adair; Paul Winistorfer

    2005-01-01

    The U.S. has long been the world's largest market for wood and wood products, fueled by its demand for wood-frame housing. But forest product markets are changing, both in terns of where the products originate (domestically or abroad),and what products are being produced and consumed.

  18. Rapid species responses to changes in climate require stringent climate protection targets

    NARCIS (Netherlands)

    Vliet, van A.J.H.; Leemans, R.

    2006-01-01

    The Avoiding Dangerous Climate Change book consolidates the scientific findings of the Exeter conference and gives an account of the most recent developments on critical thresholds and key vulnerabilities of the climate system, impacts on human and natural systems, emission pathways and

  19. Rapid evolution of phenology during range expansion with recent climate change

    NARCIS (Netherlands)

    Lustenhouwer, N.; Wilschut, R.A.; Williams, J.L.; van der Putten, W.H.; Levine, J.M.

    2018-01-01

    Although climate warming is expected to make habitat beyond species’ current cold range edge suitable for future colonization, this new habitat may present an array of biotic or abiotic conditions not experienced within the current range. Species’ ability to shift their range with climate change may

  20. A novel system for rapid measurement of high-frequency magnetic properties of toroidal cores of different sizes

    CERN Document Server

    Derebasi, N; Moses, A J; Fox, D

    2000-01-01

    A novel system for power loss and B-H measurements on toroidal magnetic cores was built to operate up to 200 kHz. Measurement data taken using sophisticated software at 10 MHz sampling rate and 16-bit resolution shows the system is versatile and can be used to test a wide range of core sizes and materials with an error <+-3%.

  1. Introducing a new and rapid microextraction approach based on magnetic ionic liquids: Stir bar dispersive liquid microextraction.

    Science.gov (United States)

    Chisvert, Alberto; Benedé, Juan L; Anderson, Jared L; Pierson, Stephen A; Salvador, Amparo

    2017-08-29

    With the aim of contributing to the development and improvement of microextraction techniques, a novel approach combining the principles and advantages of stir bar sorptive extraction (SBSE) and dispersive liquid-liquid microextraction (DLLME) is presented. This new approach, termed stir bar dispersive liquid microextraction (SBDLME), involves the addition of a magnetic ionic liquid (MIL) and a neodymium-core magnetic stir bar into the sample allowing the MIL coat the stir bar due to physical forces (i.e., magnetism). As long as the stirring rate is maintained at low speed, the MIL resists rotational (centrifugal) forces and remains on the stir bar surface in a manner closely resembling SBSE. By increasing the stirring rate, the rotational forces surpass the magnetic field and the MIL disperses into the sample solution in a similar manner to DLLME. After extraction, the stirring is stopped and the MIL returns to the stir bar without the requirement of an additional external magnetic field. The MIL-coated stir bar containing the preconcentrated analytes is thermally desorbed directly into a gas chromatographic system coupled to a mass spectrometric detector (TD-GC-MS). This novel approach opens new insights into the microextraction field, by using the benefits provided by SBSE and DLLME simultaneously, such as automated thermal desorption and high surface contact area, respectively, but most importantly, it enables the use of tailor-made solvents (i.e., MILs). To prove its utility, SBDLME has been used in the extraction of lipophilic organic UV filters from environmental water samples as model analytical application with excellent analytical features in terms of linearity, enrichment factors (67-791), limits of detection (low ng L -1 ), intra- and inter-day repeatability (RSD<15%) and relative recoveries (87-113%, 91-117% and 89-115% for river, sea and swimming pool water samples, respectively). Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Rapid characterisation of vegetation structure to predict refugia and climate change impacts across a global biodiversity hotspot.

    Directory of Open Access Journals (Sweden)

    Antonius G T Schut

    Full Text Available Identification of refugia is an increasingly important adaptation strategy in conservation planning under rapid anthropogenic climate change. Granite outcrops (GOs provide extraordinary diversity, including a wide range of taxa, vegetation types and habitats in the Southwest Australian Floristic Region (SWAFR. However, poor characterization of GOs limits the capacity of conservation planning for refugia under climate change. A novel means for the rapid identification of potential refugia is presented, based on the assessment of local-scale environment and vegetation structure in a wider region. This approach was tested on GOs across the SWAFR. Airborne discrete return Light Detection And Ranging (LiDAR data and Red Green and Blue (RGB imagery were acquired. Vertical vegetation profiles were used to derive 54 structural classes. Structural vegetation types were described in three areas for supervised classification of a further 13 GOs across the region. Habitat descriptions based on 494 vegetation plots on and around these GOs were used to quantify relationships between environmental variables, ground cover and canopy height. The vegetation surrounding GOs is strongly related to structural vegetation types (Kappa = 0.8 and to its spatial context. Water gaining sites around GOs are characterized by taller and denser vegetation in all areas. The strong relationship between rainfall, soil-depth, and vegetation structure (R(2 of 0.8-0.9 allowed comparisons of vegetation structure between current and future climate. Significant shifts in vegetation structural types were predicted and mapped for future climates. Water gaining areas below granite outcrops were identified as important putative refugia. A reduction in rainfall may be offset by the occurrence of deeper soil elsewhere on the outcrop. However, climate change interactions with fire and water table declines may render our conclusions conservative. The LiDAR-based mapping approach presented

  3. MAGNET

    CERN Multimedia

    by B. Curé

    2011-01-01

    The magnet operation was very satisfactory till the technical stop at the end of the year 2010. The field was ramped down on 5th December 2010, following the successful regeneration test of the turbine filters at full field on 3rd December 2010. This will limit in the future the quantity of magnet cycles, as it is no longer necessary to ramp down the magnet for this type of intervention. This is made possible by the use of the spare liquid Helium volume to cool the magnet while turbines 1 and 2 are stopped, leaving only the third turbine in operation. This obviously requires full availability of the operators to supervise the operation, as it is not automated. The cryogenics was stopped on 6th December 2010 and the magnet was left without cooling until 18th January 2011, when the cryoplant operation resumed. The magnet temperature reached 93 K. The maintenance of the vacuum pumping was done immediately after the magnet stop, when the magnet was still at very low temperature. Only the vacuum pumping of the ma...

  4. Strain on the san andreas fault near palmdale, california: rapid, aseismic change.

    Science.gov (United States)

    Savage, J C; Prescott, W H; Lisowski, M; King, N E

    1981-01-02

    Frequently repeated strain measurements near Palmdale, California, during the period from 1971 through 1980 indicate that, in addition to a uniform accumulation of right-lateral shear strain (engineering shear, 0.35 microradian per year) across the San Andreas fault, a 1-microstrain contraction perpendicular to the fault that accumulated gradually during the interval 1974 through 1978 was aseismically released between February and November 1979. Subsequently (November 1979 to March 1980), about half of the contraction was recovered. This sequence of strain changes can be explained in terms of south-southwestward migration of a slip event consisting of the south-southwestward movement of the upper crust on a horizontal detachment surface at a depth of 10 to 30 kilometers. The large strain change in 1979 corresponds to the passage of the slip event beneath the San Andreas fault.

  5. Rapid response of a marine mammal species to holocene climate and habitat change.

    Directory of Open Access Journals (Sweden)

    Mark de Bruyn

    2009-07-01

    Full Text Available Environmental change drives demographic and evolutionary processes that determine diversity within and among species. Tracking these processes during periods of change reveals mechanisms for the establishment of populations and provides predictive data on response to potential future impacts, including those caused by anthropogenic climate change. Here we show how a highly mobile marine species responded to the gain and loss of new breeding habitat. Southern elephant seal, Mirounga leonina, remains were found along the Victoria Land Coast (VLC in the Ross Sea, Antarctica, 2,500 km from the nearest extant breeding site on Macquarie Island (MQ. This habitat was released after retreat of the grounded ice sheet in the Ross Sea Embayment 7,500-8,000 cal YBP, and is within the range of modern foraging excursions from the MQ colony. Using ancient mtDNA and coalescent models, we tracked the population dynamics of the now extinct VLC colony and the connectivity between this and extant breeding sites. We found a clear expansion signal in the VLC population approximately 8,000 YBP, followed by directional migration away from VLC and the loss of diversity at approximately 1,000 YBP, when sea ice is thought to have expanded. Our data suggest that VLC seals came initially from MQ and that some returned there once the VLC habitat was lost, approximately 7,000 years later. We track the founder-extinction dynamics of a population from inception to extinction in the context of Holocene climate change and present evidence that an unexpectedly diverse, differentiated breeding population was founded from a distant source population soon after habitat became available.

  6. Currency and Competence of Occupational Therapists and Consumers with Rapidly Changing Technology

    OpenAIRE

    Steel, Emily J.; Buchanan, Ricky; Layton, Natasha; Wilson, Erin

    2017-01-01

    Assistive technology was once a specialised field of practice, involving products designed for populations with specific impairments or functional goals. In Australia, occupational therapists have, at times, functioned as gatekeepers to public funding, prescribing products from a predefined list. An expanding range of accessible mainstream products available via international and online markets has changed the meaning and application of assistive technology for many people with disability. In...

  7. Symptoms and Mucosal Changes Stable During Rapid Increase of Pediatric Celiac Disease in Norway.

    Science.gov (United States)

    Beitnes, Ann-Christin R; Vikskjold, Florin B; Jóhannesdóttir, Gróa B; Perminow, Gøri; Olbjørn, Christine; Andersen, Solveig N; Bentsen, Beint S; Rugtveit, Jarle; Størdal, Ketil

    2017-04-01

    We aimed to study whether the incidence of pediatric celiac disease (CD) in South-Eastern Norway changed from 2000 to 2010. We also examined whether there was a change in symptoms and histopathological morphology in the duodenal biopsies during the same period. In 3 hospitals in South-Eastern Norway, records from pediatric patients (0-14.9 years) diagnosed with CD during two 3-year periods (2000-2002 and 2008-2010) were reviewed. Only cases with a duodenal biopsy diagnosis of CD classified as Marsh grade 2 and 3a-c were included. Frequencies of symptoms, anthropometric data, and laboratory results were compared, in addition to re-examinations of histological sections from one of the hospitals. A total of 400 cases were diagnosed with a female to male ratio of 1.5:1. The incidence rate for 2000 to 2002 was 15.9 cases per 100,000 person-years (95% confidence interval 12.8-19.4), compared with 45.5 cases per 100,000 person-years during 2008 to 2010 (95% confidence interval 40.5-50.9), P symptoms and the distribution of histopathological changes were similar in the 2 periods, whereas weight z scores and hemoglobin levels were significantly lower in the first period. We found a 3-fold increase in the incidence rate for CD in the Norwegian pediatric population during the decade 2000 to 2010. Slightly higher weight and hemoglobin levels at diagnosis in the latter period may be due to improved CD awareness. Unaltered relative frequencies of symptoms and histopathological changes in the gut, however, suggest a true increase of CD in Norwegian children.

  8. Historical legacies accumulate to shape future biodiversity in an era of rapid global change

    Czech Academy of Sciences Publication Activity Database

    Essl, F.; Dullinger, S.; Rabitsch, W.; Hulme, P. E.; Pyšek, Petr; Wilson, J. R. U.; Richardson, D. M.

    2015-01-01

    Roč. 21, č. 5 (2015), s. 534-547 ISSN 1366-9516 R&D Projects: GA ČR GB14-36079G Grant - others:AV ČR(CZ) AP1002 Program:Akademická prémie - Praemium Academiae Institutional support: RVO:67985939 Keywords : biological invasions * global change * time lags Subject RIV: EH - Ecology, Behaviour Impact factor: 4.566, year: 2015

  9. Rapid response of a marine mammal species to holocene climate and habitat change.

    Science.gov (United States)

    de Bruyn, Mark; Hall, Brenda L; Chauke, Lucas F; Baroni, Carlo; Koch, Paul L; Hoelzel, A Rus

    2009-07-01

    Environmental change drives demographic and evolutionary processes that determine diversity within and among species. Tracking these processes during periods of change reveals mechanisms for the establishment of populations and provides predictive data on response to potential future impacts, including those caused by anthropogenic climate change. Here we show how a highly mobile marine species responded to the gain and loss of new breeding habitat. Southern elephant seal, Mirounga leonina, remains were found along the Victoria Land Coast (VLC) in the Ross Sea, Antarctica, 2,500 km from the nearest extant breeding site on Macquarie Island (MQ). This habitat was released after retreat of the grounded ice sheet in the Ross Sea Embayment 7,500-8,000 cal YBP, and is within the range of modern foraging excursions from the MQ colony. Using ancient mtDNA and coalescent models, we tracked the population dynamics of the now extinct VLC colony and the connectivity between this and extant breeding sites. We found a clear expansion signal in the VLC population approximately 8,000 YBP, followed by directional migration away from VLC and the loss of diversity at approximately 1,000 YBP, when sea ice is thought to have expanded. Our data suggest that VLC seals came initially from MQ and that some returned there once the VLC habitat was lost, approximately 7,000 years later. We track the founder-extinction dynamics of a population from inception to extinction in the context of Holocene climate change and present evidence that an unexpectedly diverse, differentiated breeding population was founded from a distant source population soon after habitat became available.

  10. Next Generation of Renewable Electricity Policy: How Rapid Change is Breaking Down Conventional Policy Categories

    Energy Technology Data Exchange (ETDEWEB)

    Couture, T. D. [E3 Analytics, Berlin (Germany); Jacobs, D. [International Energy Transition (IET), Boston, MA (United States); Rickerson, W. [Meister Consultants Group, Boston, MA (United States); Healey, V. [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2015-02-01

    A number of policies have been used historically in order to stimulate the growth of the renewable electricity sector. This paper examines four of these policy instruments: competitive tendering, sometimes called renewable electricity auctions, feed-in tariffs, net metering and net billing, and tradable renewable energy certificates. In recent years, however, a number of changes to both market circumstances and to policy priorities have resulted in numerous policy innovations, including the emergence of policy hybrids. With no common language for these evolving policy mechanisms, policymakers have generally continued to use the same traditional policy labels, occasionally generating confusion as many of these new policies no longer look, or act, like their traditional predecessors. In reviewing these changes, this paper makes two separate but related claims: first, policy labels themselves are breaking down and evolving. As a result, policy comparisons that rely on the conventional labels may no longer be appropriate, or advisable. Second, as policymakers continue to adapt, we are in effect witnessing the emergence of the next generation of renewable electricity policies, a change that could have significant impacts on investment, as well as on market growth in both developed and developing countries.

  11. Fe+ ion irradiation induced changes in structural and magnetic properties of iron films

    Directory of Open Access Journals (Sweden)

    K. Papamihail

    2016-12-01

    Full Text Available 490keV Fe+ ion irradiation of 200nm thick Fe films was found to induce both structural and magnetic changes. Both, the lattice constant and the grain size increase as a function of dose and both properties follow the same power law. Irradiation induces a depth dependent magnetic profile consisting of two sublayers. The top Fe sublayer has a magnetic moment higher than that of the Fe before the irradiation whereas the bottom sublayer lower. The two sublayers are connected with the effects of Fe+ irradiation, i.e. the top sublayer with the depth in which mainly radiation damage occurs whereas the bottom one with the implantation of impinging Fe+ ions. The magnetic moments of the two sublayers have a non-monotonous variation with irradiation dose depicting a maximum for the top sublayer and a minimum for the bottom one at 96.2 dpa (‘displacements per atom’. The magnetic moment enhancement/reduction is discussed in relation with the atomic volume variation in the case of atom displacements and/or implantation effects.

  12. Object-based change detection in rapid urbanization regions with remotely sensed observations: a case study of Shenzhen, China

    Science.gov (United States)

    He, Lihuang; Dong, Guihua; Wang, Wei-Min; Yang, Lijun; Liang, Hong

    2013-10-01

    China, the most populous country on Earth, has experienced rapid urbanization which is one of the main causes of many environmental and ecological problems. Therefore, the monitoring of rapid urbanization regions and the environment is of critical importance for their sustainable development. In this study, the object-based classification is employed to detect the change of land cover in Shenzhen, which is located in South China and has been urbanized rapidly in recent three decades. First, four Landsat TM images, which were acquired on 1990, 2000 and 2010, respectively, are selected from the image database. Atmospheric corrections are conducted on these images with improved dark-object subtraction technique and surface meteorological observations. Geometric correction is processed with ground control points derived from topographic maps. Second, a region growing multi-resolution segmentation and a soft nearest neighbour classifier are used to finish object-based classification. After analyzing the fraction of difference classes over time series, we conclude that the comparison of derived land cover classes with socio-economic statistics demonstrates the strong positive correlation between built-up classes and urban population as well as gross GDP and GDPs in second and tertiary industries. Two different mechanisms of urbanization, namely new land development and redevelopment, are revealed. Consequently, we found that, the districts of Shenzhen were urbanized through different mechanisms.

  13. Threshold and resilience management of coupled urbanization and water environmental system in the rapidly changing coastal region

    International Nuclear Information System (INIS)

    Li, Yangfan; Li, Yi; Wu, Wei

    2016-01-01

    The concept of thresholds shows important implications for environmental and resource management. Here we derived potential landscape thresholds which indicated abrupt changes in water quality or the dividing points between exceeding and failing to meet national surface water quality standards for a rapidly urbanizing city on the Eastern Coast in China. The analysis of landscape thresholds was based on regression models linking each of the seven water quality variables to each of the six landscape metrics for this coupled land-water system. We found substantial and accelerating urban sprawl at the suburban areas between 2000 and 2008, and detected significant nonlinear relations between water quality and landscape pattern. This research demonstrated that a simple modeling technique could provide insights on environmental thresholds to support more-informed decision making in land use, water environmental and resilience management. - Graphical abstract: Fig. Threshold models and resilience management for water quality. Display Omitted - Highlights: • Coupling urbanization and water environmental system. • Developing threshold models of the coupled land-water systems. • Nonlinear relations between water quality variables and landscape metrics. • Enhancing resilience management of coastal rapid urbanization. - We develop environmental threshold models and provide their implications on resilience management for a coupled land-water system with rapid urbanization.

  14. Cone-beam computed tomography evaluation of dental, skeletal, and alveolar bone changes associated with bonded rapid maxillary expansion

    Directory of Open Access Journals (Sweden)

    Namrata Dogra

    2016-01-01

    Full Text Available Aims and Objectives: To evaluate skeletal changes in maxilla and its surrounding structures, changes in the maxillary dentition and maxillary alveolar bone changes produced by bonded rapid maxillary expansion (RME using cone-beam computed tomography (CBCT. Materials and Methods: The sample consisted of 10 patients (6 males and 4 females with age range 12 to 15 years treated with bonded RME. CBCT scans were performed at T1 (pretreatment and at T2 (immediately after expansion to evaluate the dental, skeletal, and alveolar bone changes. Results: RME treatment increased the overall skeletal parameters such as interorbital, zygomatic, nasal, and maxillary widths. Significant increases in buccal maxillary width was observed at first premolar, second premolar, and first molar level. There was a significant increase in arch width both on the palatal side and on the buccal side. Significant tipping of right and left maxillary first molars was seen. There were significant reductions in buccal bone plate thickness and increase in palatal bone plate thickness. Conclusions: Total expansion achieved with RME was a combination of dental, skeletal and alveolar bone changes. At the first molar level, 28.45% orthopedic, 16.03% alveolar bone bending, and 55.5% orthodontic changes were observed.

  15. Exposure to Fine Particulate Matter Leads to Rapid Heart Rate Variability Changes

    Directory of Open Access Journals (Sweden)

    Michael Riediker

    2018-01-01

    Full Text Available Introduction: Heart Rate Variability (HRV reflects the adaptability of the heart to internal and external stimuli. Reduced HRV is a predictor of post-infarction mortality. We previously found in road maintenance workers HRV-increases several hours after exposure to fine particulate matter (PM2.5. This seemed to conflict with studies where PM-exposure acutely reduced HRV. We therefore assessed whether time from exposure to HRV-assessment could explain the differences observed.Methods: On five non-consecutive days, workers carried nephelometers providing 1-min-interval PM2.5-exposure. Five-min HRV-intervals of SDNN (Standard Deviation of Normal to Normal beat intervals and pNN50 (Percentage of the interval differences exceeding 50 ms were extracted from 24-h electrocardiograms (ECGs. Following 60 min PM2.5-exposure, changes in HRV-parameters were assessed during 120-min visually and by regression analysis with control for time at work, at home, and during the night using autoregressive integrating moving average (ARIMA models to account for autocorrelation of the time-series. Additional controls included changing the time windows and including body mass index (BMI and age in the models.Result: Pattern analysis of 12,669 data points showed high modulation of mean, standard deviation (SD, and time trend of HRV (SDNN and pNN50 at low, and much reduced modulation at high PM2.5-exposures. The time trend following exposure was highly symmetrical, resembling a funnel plot. Regression analysis showed significant associations of decreasing SDNN and pNN50 (average, SD, and absolute value of time trend with increasing PM2.5-exposure, which remained significant when controlling for activity phases. Changing time windows did not change the pattern of response. Including BMI and age did not change the results.Conclusions: The reduced modulation of HRV following PM2.5-exposure is striking. It suggests strong interference with homeostatic controls. Such an

  16. Rapid behavioural gregarization in the desert locust, Schistocerca gregaria entails synchronous changes in both activity and attraction to conspecifics.

    Science.gov (United States)

    Rogers, Stephen M; Cullen, Darron A; Anstey, Michael L; Burrows, Malcolm; Despland, Emma; Dodgson, Tim; Matheson, Tom; Ott, Swidbert R; Stettin, Katja; Sword, Gregory A; Simpson, Stephen J

    2014-06-01

    Desert Locusts can change reversibly between solitarious and gregarious phases, which differ considerably in behaviour, morphology and physiology. The two phases show many behavioural differences including both overall levels of activity and the degree to which they are attracted or repulsed by conspecifics. Solitarious locusts perform infrequent bouts of locomotion characterised by a slow walking pace, groom infrequently and actively avoid other locusts. Gregarious locusts are highly active with a rapid walking pace, groom frequently and are attracted to conspecifics forming cohesive migratory bands as nymphs and/or flying swarms as adults. The sole factor driving the onset of gregarization is the presence of conspecifics. In several previous studies concerned with the mechanism underlying this transformation we have used an aggregate measure of behavioural phase state, Pgreg, derived from logistic regression analysis, which combines and weights several behavioural variables to characterise solitarious and gregarious behaviour. Using this approach we have analysed the time course of behavioural change, the stimuli that induce gregarization and the key role of serotonin in mediating the transformation. Following a recent critique that suggested that using Pgreg may confound changes in general activity with genuine gregarization we have performed a meta-analysis examining the time course of change in the individual behaviours that we use to generate Pgreg. We show that the forced crowding of solitarious locusts, tactile stimulation of the hind femora, and the short-term application of serotonin each induce concerted changes in not only locomotion-related variables but also grooming frequency and attraction to other locusts towards those characteristic of long-term gregarious locusts. This extensive meta-analysis supports and extends our previous conclusions that solitarious locusts undergo a rapid behavioural gregarization upon receiving appropriate stimulation for

  17. Introducing a new and rapid microextraction approach based on magnetic ionic liquids: Stir bar dispersive liquid microextraction

    International Nuclear Information System (INIS)

    Chisvert, Alberto; Benedé, Juan L.; Anderson, Jared L.; Pierson, Stephen A.; Salvador, Amparo

    2017-01-01

    With the aim of contributing to the development and improvement of microextraction techniques, a novel approach combining the principles and advantages of stir bar sorptive extraction (SBSE) and dispersive liquid-liquid microextraction (DLLME) is presented. This new approach, termed stir bar dispersive liquid microextraction (SBDLME), involves the addition of a magnetic ionic liquid (MIL) and a neodymium-core magnetic stir bar into the sample allowing the MIL coat the stir bar due to physical forces (i.e., magnetism). As long as the stirring rate is maintained at low speed, the MIL resists rotational (centrifugal) forces and remains on the stir bar surface in a manner closely resembling SBSE. By increasing the stirring rate, the rotational forces surpass the magnetic field and the MIL disperses into the sample solution in a similar manner to DLLME. After extraction, the stirring is stopped and the MIL returns to the stir bar without the requirement of an additional external magnetic field. The MIL-coated stir bar containing the preconcentrated analytes is thermally desorbed directly into a gas chromatographic system coupled to a mass spectrometric detector (TD-GC-MS). This novel approach opens new insights into the microextraction field, by using the benefits provided by SBSE and DLLME simultaneously, such as automated thermal desorption and high surface contact area, respectively, but most importantly, it enables the use of tailor-made solvents (i.e., MILs). To prove its utility, SBDLME has been used in the extraction of lipophilic organic UV filters from environmental water samples as model analytical application with excellent analytical features in terms of linearity, enrichment factors (67–791), limits of detection (low ng L −1 ), intra- and inter-day repeatability (RSD<15%) and relative recoveries (87–113%, 91–117% and 89–115% for river, sea and swimming pool water samples, respectively). - Highlights: • A new microextraction method combining the

  18. The Boltysh crater record of rapid vegetation change during the Dan-C2 hyperthermal event.

    Science.gov (United States)

    Jolley, D. W.; Daly, R.; Gilmour, I.; Gilmour, M.; Kelley, S. P.

    2012-04-01

    Analysis of a cored borehole drilled through the sedimentary fill of the 24km wide Boltysh meteorite crater, Ukraine has yielded a unique, high resolution record spanning algae records. These records reflect environmental change from the K/Pg1 to the post Dan-C2 Danian. Leading into the CIE, warm temperate gymnosperm - angiosperm - fern communities are replaced by precipitation limited (winterwet) plant communities within the negative CIE. Winterwet plant communities dominate the negative CIE, but are replaced within the isotope recovery stage by warm temperate floras. These in turn give way to cooler temperate floras in the post positive CIE section of the uppermost crater fill. The distribution of temperate taxa about the negative CIE represents the broadest scale of oscillatory variation in the palynofloras. Shorter frequency oscillations are evident from diversity and botanical group distributions reflecting changes in moisture availability over several thousand years. Detailed analysis of variability within one of these oscillations records plant community cyclicity across the inception of the negative CIE. This short term cyclicity provides evidence that the replacement of warm termperate by winterwet floras occurred in a stepwise manner at the negative CIE suggesting cumulative atmospheric forcing. At <1mm scale, lamination within the negative CIE showed no obvious lithological or colour differences, and are not seasonal couplets. However, palynofloral analysis of laminations from within the negative CIE has yielded evidence of annual variation identifying the potential for recoding changes in 'paleoweather' across a major hyperthermal event. [1] Jolley, D. W. et al. (2010) Geology 38, 835-838.

  19. High Resolution Topography of Age-Related Changes in Non-Rapid Eye Movement Sleep Electroencephalography.

    Directory of Open Access Journals (Sweden)

    Kate E Sprecher

    Full Text Available Sleeping brain activity reflects brain anatomy and physiology. The aim of this study was to use high density (256 channel electroencephalography (EEG during sleep to characterize topographic changes in sleep EEG power across normal aging, with high spatial resolution. Sleep was evaluated in 92 healthy adults aged 18-65 years old using full polysomnography and high density EEG. After artifact removal, spectral power density was calculated for standard frequency bands for all channels, averaged across the NREM periods of the first 3 sleep cycles. To quantify topographic changes with age, maps were generated of the Pearson's coefficient of the correlation between power and age at each electrode. Significant correlations were determined by statistical non-parametric mapping. Absolute slow wave power declined significantly with increasing age across the entire scalp, whereas declines in theta and sigma power were significant only in frontal regions. Power in fast spindle frequencies declined significantly with increasing age frontally, whereas absolute power of slow spindle frequencies showed no significant change with age. When EEG power was normalized across the scalp, a left centro-parietal region showed significantly less age-related decline in power than the rest of the scalp. This partial preservation was particularly significant in the slow wave and sigma bands. The effect of age on sleep EEG varies substantially by region and frequency band. This non-uniformity should inform the design of future investigations of aging and sleep. This study provides normative data on the effect of age on sleep EEG topography, and provides a basis from which to explore the mechanisms of normal aging as well as neurodegenerative disorders for which age is a risk factor.

  20. Coastal regime shifts: rapid responses of coastal wetlands to changes in mangrove cover.

    Science.gov (United States)

    Guo, Hongyu; Weaver, Carolyn; Charles, Sean P; Whitt, Ashley; Dastidar, Sayantani; D'Odorico, Paolo; Fuentes, Jose D; Kominoski, John S; Armitage, Anna R; Pennings, Steven C

    2017-03-01

    Global changes are causing broad-scale shifts in vegetation communities worldwide, including coastal habitats where the borders between mangroves and salt marsh are in flux. Coastal habitats provide numerous ecosystem services of high economic value, but the consequences of variation in mangrove cover are poorly known. We experimentally manipulated mangrove cover in large plots to test a set of linked hypotheses regarding the effects of changes in mangrove cover. We found that changes in mangrove cover had strong effects on microclimate, plant community, sediment accretion, soil organic content, and bird abundance within 2 yr. At higher mangrove cover, wind speed declined and light interception by vegetation increased. Air and soil temperatures had hump-shaped relationships with mangrove cover. The cover of salt marsh plants decreased at higher mangrove cover. Wrack cover, the distance that wrack was distributed from the water's edge, and sediment accretion decreased at higher mangrove cover. Soil organic content increased with mangrove cover. Wading bird abundance decreased at higher mangrove cover. Many of these relationships were non-linear, with the greatest effects when mangrove cover varied from zero to intermediate values, and lesser effects when mangrove cover varied from intermediate to high values. Temporal and spatial variation in measured variables often peaked at intermediate mangrove cover, with ecological consequences that are largely unexplored. Because different processes varied in different ways with mangrove cover, the "optimum" cover of mangroves from a societal point of view will depend on which ecosystem services are most desired. © 2016 by the Ecological Society of America.

  1. Alveolar bone changes after rapid maxillary expansion with tooth-born appliances: a systematic review.

    Science.gov (United States)

    Lo Giudice, Antonino; Barbato, Ersilia; Cosentino, Leandro; Ferraro, Claudia Maria; Leonardi, Rosalia

    2017-08-10

    During rapid maxillary expansion (RME), heavy forces are transmitted to the maxilla by the anchored teeth causing buccal inclination and buccal bone loss of posterior teeth. To systematically review the literature in order to investigate whether RME causes periodontal sequelae, assessed by cone-beam computed tomography (CBCT). Fifteen electronic databases and reference lists of studies were searched up to March 2017. To be included in the systematic review, articles must be human studies on growing subjects, with transversal maxillary deficiency treated with RME and with assessment of buccal bone loss by CBCT images. Only randomized and non-randomized trials were included. Two authors independently performed study selection, data extraction, and risk of bias assessment. Study characteristics (study design, sample size, age, sex, skeletal maturity, type of appliance, daily activation, evaluated linear measurements, observation period, CBCT settings), and study outcomes (loss of buccal bone thickness and marginal bone) were reported according to the PRISMA statement. On the basis of the applied inclusion criteria, only six articles, three randomized clinical trials and three controlled clinical trials were included. An individual analysis of the selected articles was undertaken. The risks of bias of the six trials were scored as medium to low. The results of the present systematic review are based on a limited number of studies and only one study included a control group. In all considered studies, significant loss of buccal bone thickness and marginal bone level were observed in anchored teeth, following RME. Further prospective studies correlating the radiological data of bone loss to the periodontal soft tissues reaction after RME are required. A preliminary evaluation of the patient-related risk factors for RR may be advisable when considering to administering RME. This systematic review was registered in the National Institute of Health Research database with an

  2. Polyvinyl-alcohol-based magnetic beads for rapid and efficient separation of specific or unspecific nucleic acid sequences

    International Nuclear Information System (INIS)

    Oster, J.; Parker, Jeffrey; Brassard, Lothar

    2001-01-01

    The versatile application of polyvinyl-alcohol-based magnetic M-PVA beads is demonstrated in the separation of genomic DNA, sequence specific nucleic acid purification, and binding of bacteria for subsequent DNA extraction and detection. It is shown that nucleic acids can be obtained in high yield and purity using M-PVA beads, making sample preparation efficient, fast and highly adaptable for automation processes

  3. Currency and Competence of Occupational Therapists and Consumers with Rapidly Changing Technology

    Directory of Open Access Journals (Sweden)

    Emily J. Steel

    2017-01-01

    Full Text Available Assistive technology was once a specialised field of practice, involving products designed for populations with specific impairments or functional goals. In Australia, occupational therapists have, at times, functioned as gatekeepers to public funding, prescribing products from a predefined list. An expanding range of accessible mainstream products available via international and online markets has changed the meaning and application of assistive technology for many people with disability. In the policy context of consumer choice and cost-effectiveness, have occupational therapists been left behind? This paper describes the change in context for access to assistive technology resulting in expanded possibilities for participation and inclusion. A case study of environmental control systems is used to explore the overlap of mainstream and assistive products and the funding and services to support their uptake. The analysis describes a future policy and practice context in which assistive technology includes a spectrum of products decoupled from access to independent advice and support services. A broader scope of occupational therapy practice has potential to enhance the occupational rights of people with disability and the efficiency and effectiveness of assistive technology provision.

  4. Changes to dryland rainfall result in rapid moss mortality and altered soil fertility

    Science.gov (United States)

    Reed, Sasha C.; Coe, Kirsten K.; Sparks, Jed P.; Housman, David C.; Zelikova, Tamara J.; Belnap, Jayne

    2012-01-01

    Arid and semi-arid ecosystems cover ~40% of Earth’s terrestrial surface, but we know little about how climate change will affect these widespread landscapes. Like many drylands, the Colorado Plateau in southwestern United States is predicted to experience elevated temperatures and alterations to the timing and amount of annual precipitation. We used a factorial warming and supplemental rainfall experiment on the Colorado Plateau to show that altered precipitation resulted in pronounced mortality of the widespread moss Syntrichia caninervis. Increased frequency of 1.2 mm summer rainfall events reduced moss cover from ~25% of total surface cover to fertility. Mosses are important members in many dryland ecosystems and the community changes observed here reveal how subtle modifications to climate can affect ecosystem structure and function on unexpectedly short timescales. Moreover, mortality resulted from increased precipitation through smaller, more frequent events, underscoring the importance of precipitation event size and timing, and highlighting our inadequate understanding of relationships between climate and ecosystem function in drylands.

  5. Tensile behavior change depending on the microstructure of a Fe-Cu alloy produced from rapidly solidified powder

    International Nuclear Information System (INIS)

    Kakisawa, Hideki; Minagawa, Kazumi; Halada, Kohmei

    2003-01-01

    The relationship between consolidating temperature and the tensile behavior of iron alloy produced from Fe-Cu rapidly solidified powder is investigated. Fe-Cu powder fabricated by high-pressure water atomization was consolidated by heavy rolling at 873-1273 K. Microstructural changes were observed and tensile behavior was examined. Tensile behavior varies as the consolidating temperature changes, and these temperature-dependent differences depend on the morphology of the microstructure on the order of micrometers. The sample consolidated at 873 K shows a good strength/elongation balance because the powder microstructure and primary powder boundaries are maintained. The samples consolidated at the higher temperatures have a microstructure of recrystallized grains, and these recrystallized samples show the conventional relationship between tensile behavior and grain size in ordinal bulk materials

  6. The role of the Asian winter monsoon in the rapid propagation of abrupt climate changes during the last deglaciation

    Science.gov (United States)

    Chu, Guoqiang; Sun, Qing; Zhu, Qingzeng; Shan, Yabing; Shang, Wenyu; Ling, Yuan; Su, Youliang; Xie, Manman; Wang, Xishen; Liu, Jiaqi

    2017-12-01

    High-resolution temperature records spanning the last deglaciation from low latitudes are scarce; however, they are important for understanding the rapid propagation of abrupt climate events throughout the Northern Hemisphere and the tropics. Here, we present a branched GDGTs-based temperature reconstruction from the sediments of Maar Lake Huguangyan in tropical China. The record reveals that the mean temperature during the Oldest Dryas was 17.8 °C, which was followed by a two-step increase of 2-3 °C to the Bølling-Allerød, a decrease to 19.8 °C during the Younger Dryas, and a rapid warming at the onset of the Holocene. The Oldest Dryas was about 2 °C warmer than the Younger Dryas. The reconstructed temperature was weighted towards the wintertime since the lake is monomictic and the mixing process in winter supplies nutrients from the lake bottom to the entire water column, greatly promoting biological productivity. In addition, the winter-biased temperature changes observed in the study are more distinctive than the summer-biased temperature records from extra-tropical regions of East Asia. This implies that the temperature decreases during abrupt climatic events were mainly a winter phenomenon. Within the limits of the dating uncertainties, the broadly similar pattern of winter-weighted temperature change observed in both tropical Lake Huguangyan and in Greenland ice cores indicates the occurrence of tightly-coupled interactions between high latitude ice sheets and land areas in the tropics. We suggest that the winter monsoon (especially cold surges) could play an important role in the rapid transmission of the temperature signal from the Arctic to the tropics.

  7. Extreme Temperature Exceedances Change more Rapidly Under Future Warming in Regions of non-Gaussian Short Temperature Distribution Tails

    Science.gov (United States)

    Loikith, P. C.; Neelin, J. D.; Meyerson, J.

    2017-12-01

    Regions of shorter-than-Gaussian warm and cold side temperature distribution tails are shown to occur in spatially coherent patterns in the current climate. Under such conditions, warming may be manifested in more complex ways than if the underlying distribution were close to Gaussian. For example, under a uniform warm shift, the simplest prototype for future warming, a location with a short warm side tail would experience a greater increase in extreme warm exceedances compared to if the distribution were Gaussian. Similarly, for a location with a short cold side tail, a uniform warm shift would result in a rapid decrease in extreme cold exceedances. Both scenarios carry major societal and environmental implications including but not limited to negative impacts on human and ecosystem health, agriculture, and the economy. It is therefore important for climate models to be able to realistically reproduce short tails in simulations of historical climate in order to boost confidence in projections of future temperature extremes. Overall, climate models contributing to the fifth phase of the Coupled Model Intercomparison Project capture many of the principal observed regions of short tails. This suggests the underlying dynamics and physics occur on scales resolved by the models, and helps build confidence in model projections of extremes. Furthermore, most GCMs show more rapid changes in exceedances of extreme temperature thresholds in regions of short tails. Results therefore suggest that the shape of the tails of the underlying temperature distribution is an indicator of how rapidly a location will experience changes to extreme temperature occurrence under future warming.

  8. Investigation of structural and magnetic properties of rapidly-solidified iron-silicon alloys at ambient and elevated temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Jayaraman, T. V.; Meka, V. M.; Jiang, X.; Overman, N. R.; Doyle, J.; Shield, J. E.; Mathaudhu, S. N.

    2018-04-01

    In this work, we investigated the ambient temperature structural properties (~300 K) and the ambient and high temperature (up to 900 K) direct current (DC) magnetic properties of melt-spun Fe-x wt.% Si (x = 3, 5, & 8) alloys. The wheel surface speeds selected for the study were 30 m/s and 40 m/s. The thickness, width, lattice parameter, saturation magnetization (MS), and intrinsic coercivity (HCI) of the melt spun ribbons are presented and compared with data in the literature. The ribbons produced at the lower wheel surface speed (30 m/s) were continuous having relatively uniform edges compared to the ribbons produced at the higher wheel surface speed. The thickness and the width of the melt-spun ribbons ranged between ~15-60 μm and 500-800 μm, respectively. The x-ray diffraction spectra of the melt-spun ribbons indicated the presence of disordered α-phase, irrespective of the composition, and the wheel-surface speed. The lattice parameter decreased gradually as a function of increasing silicon content from ~0.2862 nm (Fe-3 wt.% Si) to ~0.2847 nm (Fe-8 wt.% Si). Wheel surface speed was not shown to have a significant effect on the magnetization, but primarily impacted the ribbon structure. A decreasing trend in the saturation magnetization was observed as a function of increased silicon content. The intrinsic coercivity of the melt-spun alloys ranged between ~50 to 200 A/m. Elevated temperature evaluation of the magnetization in the case of Fe-3 & 5 wt.% Si alloy ribbons was distinctly different from the Fe-8 wt.% Si alloy ribbons. The curves of the as-prepared Fe-3 wt.% Si and Fe-5 wt.% Si alloy ribbons were irreversible while that of Fe-8 wt.% Si was reversible. The MS for any of the combinations of wheel surface speed and composition decreased monotonically with the increase in temperature (from 300 – 900 K). The percentage decrease in MS from 300 K to 900 K for the Fe-3 wt.% Si and Fe-5 wt.% Si alloys was ~19-22 %, while the percentage decrease in the same

  9. Single Session Low Frequency Left Dorsolateral Prefrontal Transcranial Magnetic Stimulation Changes Neurometabolite Relationships in Healthy Humans

    Directory of Open Access Journals (Sweden)

    Nathaniel R. Bridges

    2018-03-01

    Full Text Available Background: Dorsolateral prefrontal cortex (DLPFC low frequency repetitive transcranial magnetic stimulation (LF-rTMS has shown promise as a treatment and investigative tool in the medical and research communities. Researchers have made significant progress elucidating DLPFC LF-rTMS effects—primarily in individuals with psychiatric disorders. However, more efforts investigating underlying molecular changes and establishing links to functional and behavioral outcomes in healthy humans are needed.Objective: We aimed to quantify neuromolecular changes and relate these to functional changes following a single session of DLPFC LF-rTMS in healthy participants.Methods: Eleven participants received sham-controlled neuronavigated 1 Hz rTMS to the region most activated by a 7-letter Sternberg working memory task (SWMT within the left DLPFC. We quantified SWMT performance, functional magnetic resonance activation and proton Magnetic resonance spectroscopy (MRS neurometabolite measure changes before and after stimulation.Results: A single LF-rTMS session was not sufficient to change DLPFC neurometabolite levels and these changes did not correlate with DLPFC activation changes. Real rTMS, however, significantly altered neurometabolite correlations (compared to sham rTMS, both with baseline levels and between the metabolites themselves. Additionally, real rTMS was associated with diminished reaction time (RT performance improvements and increased activation within the motor, somatosensory and lateral occipital cortices.Conclusion: These results show that a single session of LF-rTMS is sufficient to influence metabolite relationships and causes widespread activation in healthy humans. Investigating correlational relationships may provide insight into mechanisms underlying LF-rTMS.

  10. Chronological change of brain abscess in {sup 1}H magnetic resonance spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Akutsu, H.; Matsumura, A.; Isobe, T.; Takano, S.; Nose, T. [Department of Neurosurgery, Institute of Clinical Medicine, University of Tsukuba, Tennodai, Tsukuba, Ibaraki (Japan); Anno, I.; Itai, Y. [Department of Radiology, Institute of Clinical Medicine, University of Tsukuba, Tennodai, Tsukuba, Ibaraki (Japan)

    2002-07-01

    We studied chronological magnetic resonance spectral changes in brain abscesses before and after medical and/or surgical treatment. We examined five patients with MRI imaging and {sup 1}H magnetic resonance spectroscopy (MRS) on two or more occasions, using two volume-of-interest patterns, and saw chronological changes related to the evolution of the abscess. A spectrum specific for brain abscess was found in three of the five cases, while two showed a single lactate peak in the first study. In two cases, phenylalanine or alanine appeared in the second study. We observed the disappearance of the specific spectra and a single lactate peak following surgery. Only one patient showed different spectra in different volume of interest. (orig.)

  11. Static magnetic field changes the activity of venom phospholipase of Vipera Lebetina snakes

    International Nuclear Information System (INIS)

    Garibova, L.S.; Avetisyan, T.O.; Ajrapetyan, S.N.

    2000-01-01

    The effect of the static magnetic field (SMF) on the phospholipid activity of the class-A snake venom is studied. The Vipera Lebetina snake venom was subjected during 10 days to 30 minute impact of the CMF daily. It is established that increase in the phospholipase A 1 and A 2 approximately by 21 and 32 % correspondingly and in the phosphodiesterase C - by 33 % was observed. The decrease in the total protein level of the snake venom by 31.6 ± 2.2 % was noted thereby. It may be assumed that the described phospholipase and phosphoesterase changes may lead to essential shifts in the total metabolic activity of cells and organism as a whole. The activity index of these ferments may serve as an indicator of changes in the environmental magnetic field [ru

  12. Rapid changes in ice core gas records - Part 1: On the accuracy of methane synchronisation of ice cores

    Science.gov (United States)

    Köhler, P.

    2010-08-01

    Methane synchronisation is a concept to align ice core records during rapid climate changes of the Dansgaard/Oeschger (D/O) events onto a common age scale. However, atmospheric gases are recorded in ice cores with a log-normal-shaped age distribution probability density function, whose exact shape depends mainly on the accumulation rate on the drilling site. This age distribution effectively shifts the mid-transition points of rapid changes in CH4 measured in situ in ice by about 58% of the width of the age distribution with respect to the atmospheric signal. A minimum dating uncertainty, or artefact, in the CH4 synchronisation is therefore embedded in the concept itself, which was not accounted for in previous error estimates. This synchronisation artefact between Greenland and Antarctic ice cores is for GRIP and Byrd less than 40 years, well within the dating uncertainty of CH4, and therefore does not calls the overall concept of the bipolar seesaw into question. However, if the EPICA Dome C ice core is aligned via CH4 to NGRIP this synchronisation artefact is in the most recent unified ice core age scale (Lemieux-Dudon et al., 2010) for LGM climate conditions of the order of three centuries and might need consideration in future gas chronologies.

  13. Rapid breeding and varietal replacement are critical to adaptation of cropping systems in the developing world to climate change.

    Science.gov (United States)

    Atlin, Gary N; Cairns, Jill E; Das, Biswanath

    2017-03-01

    Plant breeding is a key mechanism for adaptation of cropping systems to climate change. Much discussion of breeding for climate change focuses on genes with large effects on heat and drought tolerance, but phenology and stress tolerance are highly polygenic. Adaptation will therefore mainly result from continually adjusting allele frequencies at many loci through rapid-cycle breeding that delivers a steady stream of incrementally improved cultivars. This will require access to elite germplasm from other regions, shortened breeding cycles, and multi-location testing systems that adequately sample the target population of environments. The objective of breeding and seed systems serving smallholder farmers should be to ensure that they use varieties developed in the last 10 years. Rapid varietal turnover must be supported by active dissemination of new varieties, and active withdrawal of obsolete ones. Commercial seed systems in temperate regions achieve this through competitive seed markets, but in the developing world, most crops are not served by competitive commercial seed systems, and many varieties date from the end of the Green Revolution (the late 1970s, when the second generation of modern rice and wheat varieties had been widely adopted). These obsolete varieties were developed in a climate different than today's, placing farmers at risk. To reduce this risk, a strengthened breeding system is needed, with freer international exchange of elite varieties, short breeding cycles, high selection intensity, wide-scale phenotyping, and accurate selection supported by genomic technology. Governments need to incentivize varietal release and dissemination systems to continuously replace obsolete varieties.

  14. Structural Changes in Stx1 Engineering Monoclonal Antibody Improves Its Functionality as Diagnostic Tool for a Rapid Latex Agglutination Test

    Directory of Open Access Journals (Sweden)

    Daniela Luz

    2018-02-01

    Full Text Available Stx1 toxin is one of the AB5 toxins of Shiga toxin-producing Escherichia coli (STEC responsible for foodborne intoxication during outbreaks. The single-chain variable fragment (scFv is the most common recombinant antibody format; it consists of both variable chains connected by a peptide linker with conserved specificity and affinity for antigen. The drawbacks of scFv production in bacteria are the heterologous expression, conformation and stability of the molecule, which could change the affinity for the antigen. In this work, we obtained a stable and functional scFv-Stx1 in bacteria, starting from IgG produced by hybridoma cells. After structural modifications, i.e., change in protein orientation, vector and linker, its solubility for expression in bacteria was increased as well as the affinity for its antigen, demonstrated by a scFv dissociation constant (KD of 2.26 × 10−7 M. Also, it was able to recognize purified Stx1 and cross-reacted with Stx2 toxin by ELISA (Enzyme-Linked Immunosorbent Assay, and detected 88% of Stx1-producing strains using a rapid latex agglutination test. Thus, the scFv fragment obtained in the present work is a bacteria-produced tool for use in a rapid diagnosis test, providing an alternative for STEC diagnosis.

  15. Post-bleaching coral community change on southern Maldivian reefs: is there potential for rapid recovery?

    Science.gov (United States)

    Perry, C. T.; Morgan, K. M.

    2017-12-01

    Given the severity of the 2016 global bleaching event, there are major questions about how quickly reef communities will recover. Here, we explore the ecological and physical structural changes that occurred across five atoll interior reefs in the southern Maldives using data collected at 6 and 12 months post-bleaching. Following initial severe coral mortality, further minor coral mortality had occurred by 12 months post-bleaching, and coral cover is now low (transitions to rubble-dominated states will occur in the near future. Juvenile coral densities in shallow fore-reef habitats are also exceptionally low (<6 individuals m-2), well below those measured 9-12 months following the 1998 bleaching event, and below recovery thresholds identified on other Indian Ocean reefs. Our findings suggest that the physical structure of these reefs will need to decline further before effective recruitment and recovery can begin.

  16. Modification of a whole room indirect calorimeter for measurement of rapid changes in energy expenditure.

    Science.gov (United States)

    Sun, M; Reed, G W; Hill, J O

    1994-06-01

    Whole room indirect calorimeters are among the most accurate devices for measurement of human energy expenditure and have provided useful data about determinants of total daily energy expenditure. However, a limitation of whole room indirect calorimeters has been the inability to detect acute (usually calorimeter (respiratory chamber) to allow accurate measurement of energy expenditure over time periods as short as 1 min. The modifications involve changes in the system design and use of signal processing techniques. With these modifications, we can measure energy expenditure in 1-min intervals throughout the day. This allows accurate study of the acute effects of food, exercise, or drugs on energy expenditure in subjects moving freely inside the respiratory chamber. The ability to use respiratory chambers for these types of studies should improve our understanding of how body weight is regulated.

  17. Fluvial response to the last Holocene rapid climate change in the Northwestern Mediterranean coastlands

    Science.gov (United States)

    Degeai, Jean-Philippe; Devillers, Benoît; Blanchemanche, Philippe; Dezileau, Laurent; Oueslati, Hamza; Tillier, Margaux; Bohbot, Hervé

    2017-05-01

    The variability of fluvial activity in the Northwestern Mediterranean coastal lowlands and its relationship with modes of climate change were analysed from the late 9th to the 18th centuries CE. Geochemical analyses were undertaken from a lagoonal sequence and surrounding sediments in order to track the fluvial inputs into the lagoon. An index based on the K/S and Rb/S ratios was used to evidence the main periods of fluvial activity. This index reveals that the Medieval Climate Anomaly (MCA) was a drier period characterized by a lower fluvial activity, while the Little Ice Age (LIA) was a wetter period with an increase of the river dynamics. Three periods of higher than average fluvial activity were evidenced at the end of the first millennium CE (ca. 900-950 cal yr CE), in the first half of the second millennium CE (ca. 1150-1550 cal yr CE), and during the 1600s-1700s CE (ca. 1650-1800 cal yr CE). The comparison of these fluvial periods with other records of riverine or lacustrine floods in Spain, Italy, and South of France seems to indicate a general increase in fluvial and flood patterns in the Northwestern Mediterranean in response to the climate change from the MCA to the LIA, although some episodes of flooding are not found in all records. Besides, the phases of higher than average fluvial dynamics are in good agreement with the North Atlantic cold events evidenced from records of ice-rafted debris. The evolution of fluvial activity in the Northwestern Mediterranean coastlands during the last millennium could have been driven by atmospheric and oceanic circulation patterns.

  18. Logarithmic superposition of force response with rapid length changes in relaxed porcine airway smooth muscle.

    Science.gov (United States)

    Ijpma, G; Al-Jumaily, A M; Cairns, S P; Sieck, G C

    2010-12-01

    We present a systematic quantitative analysis of power-law force relaxation and investigate logarithmic superposition of force response in relaxed porcine airway smooth muscle (ASM) strips in vitro. The term logarithmic superposition describes linear superposition on a logarithmic scale, which is equivalent to multiplication on a linear scale. Additionally, we examine whether the dynamic response of contracted and relaxed muscles is dominated by cross-bridge cycling or passive dynamics. The study shows the following main findings. For relaxed ASM, the force response to length steps of varying amplitude (0.25-4% of reference length, both lengthening and shortening) are well-fitted with power-law functions over several decades of time (10⁻² to 10³ s), and the force response after consecutive length changes is more accurately fitted assuming logarithmic superposition rather than linear superposition. Furthermore, for sinusoidal length oscillations in contracted and relaxed muscles, increasing the oscillation amplitude induces greater hysteresivity and asymmetry of force-length relationships, whereas increasing the frequency dampens hysteresivity but increases asymmetry. We conclude that logarithmic superposition is an important feature of relaxed ASM, which may facilitate a more accurate prediction of force responses in the continuous dynamic environment of the respiratory system. In addition, the single power-function response to length changes shows that the dynamics of cross-bridge cycling can be ignored in relaxed muscle. The similarity in response between relaxed and contracted states implies that the investigated passive dynamics play an important role in both states and should be taken into account.

  19. Long-Term Soil Experiments: A Key to Managing Earth's Rapidly Changing Critical Zones

    Science.gov (United States)

    Richter, D., Jr.

    2014-12-01

    In a few decades, managers of Earth's Critical Zones (biota, humans, land, and water) will be challenged to double food and fiber production and diminish adverse effects of management on the wider environment. To meet these challenges, an array of scientific approaches is being used to increase understanding of Critical Zone functioning and evolution, and one amongst these approaches needs to be long-term soil field studies to move us beyond black boxing the belowground Critical Zone, i.e., to further understanding of processes driving changes in the soil environment. Long-term soil experiments (LTSEs) provide direct observations of soil change and functioning across time scales of decades, data critical for biological, biogeochemical, and environmental assessments of sustainability; for predictions of soil fertility, productivity, and soil-environment interactions; and for developing models at a wide range of temporal and spatial scales. Unfortunately, LTSEs globally are not in a good state, and they take years to mature, are vulnerable to loss, and even today remain to be fully inventoried. Of the 250 LTSEs in a web-based network, results demonstrate that soils and belowground Critical Zones are highly dynamic and responsive to human management. The objective of this study is to review the contemporary state of LTSEs and consider how they contribute to three open questions: (1) can soils sustain a doubling of food production in the coming decades without further impinging on the wider environment, (2) how do soils interact with the global C cycle, and (3) how can soil management establish greater control over nutrient cycling. While LTSEs produce significant data and perspectives for all three questions, there is on-going need and opportunity for reviews of the long-term soil-research base, for establishment of an efficiently run network of LTSEs aimed at sustainability and improving management control over C and nutrient cycling, and for research teams that

  20. Rapid realist review of the evidence: achieving lasting change when mental health rehabilitation staff undertake recovery-oriented training.

    Science.gov (United States)

    Gee, Melanie; Bhanbhro, Sadiq; Cook, Sarah; Killaspy, Helen

    2017-08-01

    The aim of this study was to identify the factors contributing to lasting change in practice following a recovery-based training intervention for inpatient mental health rehabilitation staff. Staff training may help nurses and other staff groups in inpatient mental health rehabilitative settings to increase their recovery-oriented practice. There are no published reviews on the effectiveness of such training and few long-term evaluations. This review informed a realist evaluation of a specific intervention (GetREAL). Rapid realist review methodology was used to generate and prioritize programme theories. ASSIA, CINAHL, Cochrane Library, Medline, PsycINFO, Scopus, Web of Science and grey literature searches were performed in September 2014-March 2015 with no date restrictions. Stakeholders suggested further documents. GetREAL project documentation was consulted. Programme theory development took place iteratively with literature identification. Stakeholders validated and prioritized emerging programme theories and the prioritized theories were refined using literature case studies. Fifty-one relevant documents fed into 49 programme theories articulating seven mechanisms for lasting change. Prioritized mechanisms were: staff receptiveness to change; and staff feeling encouraged, motivated and supported by colleagues and management to change. Seven programme theories were prioritized and refined using data from four case studies. Lasting change can be facilitated by collaborative action planning, regular collaborative meetings, appointing a change agent, explicit management endorsement and prioritization and modifying organizational structures. Conversely, a challenging organizational climate, or a prevalence of 'change fatigue', may block change. Pre-intervention exploration may help identify any potential barriers to embedding recovery in the organizational culture. © 2016 John Wiley & Sons Ltd.

  1. Rapid environmental change over the past decade revealed by isotopic analysis of the California mussel in the northeast Pacific.

    Directory of Open Access Journals (Sweden)

    Catherine A Pfister

    Full Text Available The anthropogenic input of fossil fuel carbon into the atmosphere results in increased carbon dioxide (CO(2 into the oceans, a process that lowers seawater pH, decreases alkalinity and can inhibit the production of shell material. Corrosive water has recently been documented in the northeast Pacific, along with a rapid decline in seawater pH over the past decade. A lack of instrumentation prior to the 1990s means that we have no indication whether these carbon cycle changes have precedence or are a response to recent anthropogenic CO(2 inputs. We analyzed stable carbon and oxygen isotopes (δ(13C, δ(18O of decade-old California mussel shells (Mytilus californianus in the context of an instrumental seawater record of the same length. We further compared modern shells to shells from 1000 to 1340 years BP and from the 1960s to the present and show declines in the δ(13C of modern shells that have no historical precedent. Our finding of decline in another shelled mollusk (limpet and our extensive environmental data show that these δ(13C declines are unexplained by changes to the coastal food web, upwelling regime, or local circulation. Our observed decline in shell δ(13C parallels other signs of rapid changes to the nearshore carbon cycle in the Pacific, including a decline in pH that is an order of magnitude greater than predicted by an equilibrium response to rising atmospheric CO(2, the presence of low pH water throughout the region, and a record of a similarly steep decline in δ(13C in algae in the Gulf of Alaska. These unprecedented changes and the lack of a clear causal variable underscores the need for better quantifying carbon dynamics in nearshore environments.

  2. The impacts of climate change on poverty in 2030, and the potential from rapid, inclusive and climate-informed development

    Science.gov (United States)

    Rozenberg, J.; Hallegatte, S.

    2016-12-01

    There is a consensus on the fact that poor people are more vulnerable to climate change than the rest of the population, but, until recently, few quantified estimates had been proposed and few frameworks existed to design policies for addressing the issue. In this paper, we analyze the impacts of climate change on poverty using micro-simulation approaches. We start from household surveys that describe the current distribution of income and occupations, we project these households into the future and we look at the impacts of climate change on people's income. To project households into the future, we explore a large range of assumptions on future demographic changes (including on education), technological changes, and socio-economic trends (including redistribution policies). This approach allows us to identify the main combination of factors that lead to fast poverty reduction, and the ones that lead to high climate change impacts on the poor. Identifying these factors is critical for designing efficient policies to protect the poorest from climate change impacts and making economic growth more inclusive. Conclusions are twofold. First, by 2030 climate change can have a large impact on poverty, with between 3 and 122 million more people in poverty, but climate change remains a secondary driver of poverty trends within this time horizon. Climate change impacts do not only affect the poorest: in 2030, the bottom 40 percent lose more than 4 percent of income in many countries. The regional hotspots are Sub-Saharan Africa and - to a lesser extent - India and the rest of South Asia. The most important channel through which climate change increases poverty is through agricultural income and food prices. Second, by 2030 and in the absence of surprises on climate impacts, inclusive climate-informed development can prevent most of (but not all) the impacts on poverty. In a scenario with rapid, inclusive and climate-proof development, climate change impact on poverty is

  3. A novel molecularly imprinted material based on magnetic halloysite nanotubes for rapid enrichment of 2,4-dichlorophenoxyacetic acid in water.

    Science.gov (United States)

    Zhong, Shian; Zhou, Chengyun; Zhang, Xiaona; Zhou, Hui; Li, Hui; Zhu, Xiaohong; Wang, Yan

    2014-07-15

    A new type of magnetic halloysite nanotubes molecularly imprinted polymer (MHNTs@MIP) based on halloysite nanotubes (HNTs) with embedded magnetic nanoparticles was introduced in this study. MHNTs@MIP was prepared through surface imprinting technology, using 2,4-dichlorophenoxyacetic acid (2,4-D) as a template, 4-vinylpyridine as the monomer, divinylbenzene as cross-linking agents, and 2,2-azodiisobutyronitrile as initiator. MHNTs@MIP was characterized by Fourier Transform Infrared Spectrometer, transmission electron microscopy, X-ray diffraction, and vibrating sample magnetometer. MHNTs@MIP exhibited rapid and reliable analysis with supermagnetic properties, as well as repeated use and template-specific recognition. The adsorption capacity of magnetic halloysite nanotubes non-imprinted polymer (MHNTs@NIP) and MHNTs@MIP was 10.3mg/g and 35.2mg/g, respectively. In the detailed discussion on specific selectivity, MHNTs@MIP can be applied as an adsorbent for sample pretreatment extraction and obtain high recoveries of about 85-94%. After extraction, high-performance liquid chromatography was used to detect 2,4-D residue in water. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Ecoregional-scale monitoring within conservation areas, in a rapidly changing climate

    Science.gov (United States)

    Beever, Erik A.; Woodward, Andrea

    2011-01-01

    Long-term monitoring of ecological systems can prove invaluable for resource management and conservation. Such monitoring can: (1) detect instances of long-term trend (either improvement or deterioration) in monitored resources, thus providing an early-warning indication of system change to resource managers; (2) inform management decisions and help assess the effects of management actions, as well as anthropogenic and natural disturbances; and (3) provide the grist for supplemental research on mechanisms of system dynamics and cause-effect relationships (Fancy et al., 2009). Such monitoring additionally provides a snapshot of the status of monitored resources during each sampling cycle, and helps assess whether legal standards and regulations are being met. Until the last 1-2 decades, tracking and understanding changes in condition of natural resources across broad spatial extents have been infrequently attempted. Several factors, however, are facilitating the achievement of such broad-scale investigation and monitoring. These include increasing awareness of the importance of landscape context, greater prevalence of regional and global environmental stressors, and the rise of landscape-scale programs designed to manage and monitor biological systems. Such programs include the US Forest Service's Forest Inventory and Analysis (FIA) Program (Moser et al., 2008), Canada's National Forest Inventory, the 3Q Programme for monitoring agricultural landscapes of Norway (Dramstad et al., 2002), and the emerging (US) Landscape Conservation Cooperatives (USDOI Secretarial Order 3289, 2009; Anonymous, 2011). This Special Section explores the underlying design considerations, as well as many pragmatic aspects associated with program implementation and interpretation of results from broad-scale monitoring systems, particularly within the constraints of high-latitude contexts (e.g., low road density, short field season, dramatic fluctuations in temperature). Although Alaska is

  5. Dayside magnetopause transients correlated with changes of the magnetosheath magnetic field orientation

    Directory of Open Access Journals (Sweden)

    O. Tkachenko

    2011-04-01

    Full Text Available The paper analyses one long-term pass (26 August 2007 of the THEMIS spacecraft across the dayside low-latitude magnetopause. THEMIS B, serving partly as a magnetosheath monitor, observed several changes of the magnetic field that were accompanied by dynamic changes of the magnetopause location and/or the structure of magnetopause layers observed by THEMIS C, D, and E, whereas THEMIS A scanned the inner magnetosphere. We discuss the plasma and the magnetic field data with motivation to identify sources of observed quasiperiodic plasma transients. Such events at the magnetopause are usually attributed to pressure pulses coming from the solar wind, foreshock fluctuations, flux transfer events or surface waves. The presented transient events differ in nature (the magnetopause surface deformation, the low-latitude boundary layer thickening, the crossing of the reconnection site, but we found that all of them are associated with changes of the magnetosheath magnetic field orientation and with enhancements or depressions of the plasma density. Since these features are not observed in the data of upstream monitors, the study emphasizes the role of magnetosheath fluctuations in the solar wind-magnetosphere coupling.

  6. Magnetic ordering induced giant optical property change in tetragonal BiFeO3

    Science.gov (United States)

    Tong, Wen-Yi; Ding, Hang-Chen; Gong, Shi Jing; Wan, Xiangang; Duan, Chun-Gang

    2015-12-01

    Magnetic ordering could have significant influence on band structures, spin-dependent transport, and other important properties of materials. Its measurement, especially for the case of antiferromagnetic (AFM) ordering, however, is generally difficult to be achieved. Here we demonstrate the feasibility of magnetic ordering detection using a noncontact and nondestructive optical method. Taking the tetragonal BiFeO3 (BFO) as an example and combining density functional theory calculations with tight-binding models, we find that when BFO changes from C1-type to G-type AFM phase, the top of valance band shifts from the Z point to Γ point, which makes the original direct band gap become indirect. This can be explained by Slater-Koster parameters using the Harrison approach. The impact of magnetic ordering on band dispersion dramatically changes the optical properties. For the linear ones, the energy shift of the optical band gap could be as large as 0.4 eV. As for the nonlinear ones, the change is even larger. The second-harmonic generation coefficient d33 of G-AFM becomes more than 13 times smaller than that of C1-AFM case. Finally, we propose a practical way to distinguish the two AFM phases of BFO using the optical method, which is of great importance in next-generation information storage technologies.

  7. MAGNET

    CERN Multimedia

    Benoit Curé

    2010-01-01

    Operation of the magnet has gone quite smoothly during the first half of this year. The magnet has been at 4.5K for the full period since January. There was an unplanned short stop due to the CERN-wide power outage on May 28th, which caused a slow dump of the magnet. Since this occurred just before a planned technical stop of the LHC, during which access in the experimental cavern was authorized, it was decided to leave the magnet OFF until 2nd June, when magnet was ramped up again to 3.8T. The magnet system experienced a fault also resulting in a slow dump on April 14th. This was triggered by a thermostat on a filter choke in the 20kA DC power converter. The threshold of this thermostat is 65°C. However, no variation in the water-cooling flow rate or temperature was observed. Vibration may have been the root cause of the fault. All the thermostats have been checked, together with the cables, connectors and the read out card. The tightening of the inductance fixations has also been checked. More tem...

  8. MAGNET

    CERN Multimedia

    B. Curé

    2012-01-01

      The magnet was energised at the beginning of March 2012 at a low current to check all the MSS safety chains. Then the magnet was ramped up to 3.8 T on 6 March 2012. Unfortunately two days later an unintentional switch OFF of the power converter caused a slow dump. This was due to a misunderstanding of the CCC (CERN Control Centre) concerning the procedure to apply for the CMS converter control according to the beam-mode status at that time. Following this event, the third one since 2009, a discussion was initiated to define possible improvement, not only on software and procedures in the CCC, but also to evaluate the possibility to upgrade the CMS hardware to prevent such discharge from occurring because of incorrect procedure implementations. The magnet operation itself was smooth, and no power cuts took place. As a result, the number of magnetic cycles was reduced to the minimum, with only two full magnetic cycles from 0 T to 3.8 T. Nevertheless the magnet suffered four stops of the cryogeni...

  9. MAGNET

    CERN Multimedia

    B. Curé

    2012-01-01

      Following the unexpected magnet stops last August due to sequences of unfortunate events on the services and cryogenics [see CMS internal report], a few more events and initiatives again disrupted the magnet operation. All the magnet parameters stayed at their nominal values during this period without any fault or alarm on the magnet control and safety systems. The magnet was stopped for the September technical stop to allow interventions in the experimental cavern on the detector services. On 1 October, to prepare the transfer of the liquid nitrogen tank on its new location, several control cables had to be removed. One cable was cut mistakenly, causing a digital input card to switch off, resulting in a cold-box (CB) stop. This tank is used for the pre-cooling of the magnet from room temperature down to 80 K, and for this reason it is controlled through the cryogenics control system. Since the connection of the CB was only allowed for a field below 2 T to avoid the risk of triggering a fast d...

  10. Curie Temperature and Microstructural Changes Due to the Heating Treatment of Magnetic Amorphous Materials

    Directory of Open Access Journals (Sweden)

    Gondro J.

    2016-03-01

    Full Text Available Three distinct alloys: Fe86Zr7Nb1Cu1B5, Fe82Zr7Nb2Cu1B8, and Fe81Pt5Zr7Nb1Cu1B5 were characterized both magnetically and structurally. The samples, obtained with spinning roller method as a ribbons 3 mm in width and 20 μm thick, were investigated as-quenched and after each step of a multi steps heating treatment procedure. Each sample was annealed at four steps, fifteen minutes at every temperature, starting from 573K+600K up to +700K depending on type of alloy. Mössbauer spectroscopy data and transmission electron microscope (HRE M pictures confirmed that the as-quenched samples are fully amorphous. This is not changed after the first stages of treatment heating leads to a reduction of free volumes. The heating treatment has a great influence on the magnetic susceptibilities. The treatment up to 600K improves soft magnetic properties: an χ increase was observed, from about 400 to almost 1000 for the samples of alloys without Pt, and from about 200 to 450 at maximum, for the Fe81Pt5Zr7Nb1Cu1B5. Further heating, at more elevated temperatures, leads to magnetic hardening of the samples. Curie temperatures, established from the location of Hopkinson’s maxima on the χ(T curve are in very good agreement with those obtained from the data of specific magnetization, σ(T, measured in a field of 0.75T. As a critical parameter β was chosen to be equal 0.36 for these calculations, it confirmed that the alloys may be considered as ferromagnetic of Heisenberg type. Heating treatment resulted in decreasing of TC. These changes are within a range of several K.

  11. Analysis of changes in water cycle across Northern Eurasia with Rapid Integrated Mapping and Analysis System (RIMS)

    Science.gov (United States)

    Shiklomanov, A.; Prusevich, A.

    2012-04-01

    Historical and contemporary changes in various components of the hydrological cycle across the Northern Eurasia have been investigated using multiple observational and modeled data compiled in Rapid Integrated Mapping and Analysis System (RIMS) for North Eurasian Earth Science Partnership Initiative (NEESPI). To evaluate potential future patterns of change in the Northern Eurasian water cycle we have used climate change projections simulated by several coupled Atmosphere-Ocean General Circulation Models (AO GCMs). Future changes in hydrological regime were assessed using the UNH Water Balance and Water Transport Models (WBM/WTM) which take into account water management including irrigation and reservoir regulation. We found significant shifts in the regional hydrology and quantified potential natural and anthropogenic causes of these changes. The results of our historical and future analysis have demonstrated an intensification of hydrological cycle in many regions of the Northern Eurasia observed over 50-60 year period with accelerated rate during the last decade. Based on climate projections we can expect that the current rate of changes to continue over the course of XXI century. A significant part of the analysis and quantitative estimates of water cycle trends in Northern Eurasia has been done using RIMS online and offline data analysis tools. RIMS has been developed by the Water Systems Analysis Group at the University of New Hampshire, USA for the NEESPI program. Presently, the RIMS data pool is composed of a variety of themes including climate, hydrology, land cover, human dimension, and others. It comprises over five thousand single layer (e.g. soil type) and time series (e.g. daily runoff) raster GIS coverages, and a number of climate and hydrology station/point network datasets. The system streamlines data mining, management and model feeds in the computational environment of large and diverse data holdings. In this presentation we want to demonstrate

  12. Rapid changes in the light/dark cycle disrupt memory of conditioned fear in mice.

    Directory of Open Access Journals (Sweden)

    Dawn H Loh

    Full Text Available BACKGROUND: Circadian rhythms govern many aspects of physiology and behavior including cognitive processes. Components of neural circuits involved in learning and memory, e.g., the amygdala and the hippocampus, exhibit circadian rhythms in gene expression and signaling pathways. The functional significance of these rhythms is still not understood. In the present study, we sought to determine the impact of transiently disrupting the circadian system by shifting the light/dark (LD cycle. Such "jet lag" treatments alter daily rhythms of gene expression that underlie circadian oscillations as well as disrupt the synchrony between the multiple oscillators found within the body. METHODOLOGY/PRINCIPAL FINDINGS: We subjected adult male C57Bl/6 mice to a contextual fear conditioning protocol either before or after acute phase shifts of the LD cycle. As part of this study, we examined the impact of phase advances and phase delays, and the effects of different magnitudes of phase shifts. Under all conditions tested, we found that recall of fear conditioned behavior was specifically affected by the jet lag. We found that phase shifts potentiated the stress-evoked corticosterone response without altering baseline levels of this hormone. The jet lag treatment did not result in overall sleep deprivation, but altered the temporal distribution of sleep. Finally, we found that prior experience of jet lag helps to compensate for the reduced recall due to acute phase shifts. CONCLUSIONS/SIGNIFICANCE: Acute changes to the LD cycle affect the recall of fear-conditioned behavior. This suggests that a synchronized circadian system may be broadly important for normal cognition and that the consolidation of memories may be particularly sensitive to disruptions of circadian timing.

  13. Temperature change of various ferrite particles with alternating magnetic field for hyperthermic application

    International Nuclear Information System (INIS)

    Kim, Dong-Hyun; Lee, Se-Ho; Kim, Kyoung-Nam; Kim, Kwang-Mahn; Shim, In-Bo; Lee, Yong-Keun

    2005-01-01

    Various ferrites (Fe-, Li-, Ni/Zn/Cu-, Co-, Co/Ni, Ba- and Sr-ferrites) were investigated with respect to their application for hyperthermia. Temperature changes under an alternating magnetic field were observed. The area of hysteresis loop was much larger in the Ba- and Sr-ferrites than for that of the Fe-, Ni/Zn/Cu-, Li-, Co- and Co/Ni-ferrites. Co-ferrite exhibited the most applicable temperature change ΔT=19.25K (29.62W/gs), in distilled water when the field was 110A/m

  14. Mandibular dental arch short and long-term spontaneous dentoalveolar changes after slow or rapid maxillary expansion: a systematic review

    Directory of Open Access Journals (Sweden)

    Arthur César de Medeiros Alves

    Full Text Available ABSTRACT Objective: The aim of this systematic review was to analyze the short and long-term spontaneous dentoalveolar changes of the mandibular dental arch after slow (SME or rapid (RME maxillary expansion in the mixed and early permanent dentitions. Methods: An electronic search was performed in the following databases: PubMed/Medline, Cochrane Library, Scopus, Embase and Web of Science. Eligibility criteria for article selection included randomized controlled trials and prospective studies written in English, with no restriction of year of publication, involving patients who underwent SME or RME during the mixed or early permanent dentitions. A double-blind search of articles was performed by two reviewers. Initially, the title and the abstract of the studies were read, and their references were also hand-searched for possible missing studies. A methodological quality scoring scale was used to analyze the selected articles. Results: The search retrieved 373 articles, but only 6 were selected for review after application of the eligibility and exclusion criteria. Non-clinically significant spontaneous dentoalveolar changes of approximately 1mm were found in the mandibular dental arch in the short and long-term, after slow or rapid maxillary expansions. Furthermore, no significant differences were found between treated and control groups. Conclusions: There is enough evidence to conclude that negligible short and long-term spontaneous dentoalveolar changes tend to occur in the mandibular dental arch after SME or RME in the mixed and early permanent dentitions. More randomized studies with appropriate control group are required to better evaluate this issue.

  15. Changes in Indirect Markers of Muscle Damage and Tendons After Daily Drop Jumping Exercise with Rapid Load Increase

    Directory of Open Access Journals (Sweden)

    Vidas Paleckis, Mantas Mickevičius, Audrius Snieckus, Vytautas Streckis, Mati Pääsuke, Saulius Rutkauskas, Rasa Steponavičiūtė, Albertas Skurvydas, Sigitas Kamandulis

    2015-12-01

    Full Text Available The aim of this study was to assess changes in indirect markers of muscle damage and type I collagen degradation, as well as, patellar and Achilles tendon morphological differences during nine daily drop-jumps sessions with constant load alternated with rapid increases in load to test the hypothesis that frequent drop-jump training results in negative muscular and tendon adaptation. Young men (n = 9 performed daily drop jump workouts with progression every 3 days in terms of number of jumps, platform height and squat amplitude. Voluntary and electrically evoked knee extensor torque, muscle soreness, blood plasma creatine kinase (CK activity and carboxyterminal cross-linked telopeptide (ICTP, patellar and Achilles tendon thickness and cross-sectional area (CSA were assessed at different time points during the training period and again on days 1, 3, 10 and 17 after the training. The findings were as follows: (1 steady decline in maximal muscle strength with major recovery within 24 hours after the first six daily training sessions; (2 larger decline in electrically induced muscle torque and prolonged recovery during last three training sessions; (3 increase in patellar and Achilles tendons CSA without change in thickness towards the end of training period; (4 increase in jump height but not in muscle strength after whole training period. Our findings suggest that frequent drop-jump sessions with constant load alternated with rapid increases in load do not induce severe muscle damage or major changes in tendons, nonetheless, this type of loading is not advisable for muscle strength improvement.

  16. Sensitivity of sediment magnetic records to climate change during Holocene for the northern South China Sea

    Science.gov (United States)

    Ouyang, Tingping; Li, Mingkun; Zhao, Xiang; Zhu, Zhaoyu; Tian, Chengjing; Qiu, Yan; Peng, Xuechao; Hu, Qiao

    2016-05-01

    Magnetic property has been proved to be a sensitive proxy to climate change for both terrestrial and marine sediments. Based on the schedule frame established by AMS 14C dating of foraminifera, detail magnetic analyses were performed for core PC24 sediments at sampling intervals of 2 cm to discuss magnetic sensitivity of marine sediment to climate during Holocene for the northern South China Sea. The results indicated that: 1) Concentration dependent magnetic parameters are positive corresponding to variation of temperature. The frequency dependent susceptibility coefficient basically reflected the variation in humidity; 2) XARM/SIRM was more sensitive to detrital magnetite particles and SIRM/X was more effective to biogenic magnetite particles. Variations of XARM/SIRM and SIRM/X are corresponding to precipitation and temperature, respectively; 3) the Holocene Megathermal in the study area was identified as 7.5-3.4 cal. ka BP. The warmest stage of Holocene for the study area should be during 6.1 to 3.9 cal. ka BP; 4) The 8 ka cold event was characterized as cold and dry during 8.55 to 8.25 cal. ka BP; 5) During early and middle Holocene, the climate combinations were warm dry and cold wet. It turned to warm and wet after 2.7 cal. ka BP.

  17. Sensitivity of sediment magnetic records to climate change during Holocene for the northern South China Sea

    Directory of Open Access Journals (Sweden)

    Tingping eOuyang

    2016-05-01

    Full Text Available Magnetic property has been proved to be a sensitive proxy to climate change for both terrestrial and marine sediments. Based on the schedule frame established by AMS 14C dating of foraminifera, detail magnetic analyses were performed for core PC24 sediments at sampling intervals of 2 cm to discuss magnetic sensitivity of marine sediment to climate during Holocene for the northern South China Sea. The results indicated that: 1 Concentration dependent magnetic parameters are positive corresponding to variation of temperature. The frequency dependent susceptibility coefficient basically reflected the variation in humidity; 2 XARM/SIRM was more sensitive to detrital magnetite particles and SIRM/X was more effective to biogenic magnetite particles. Variations of XARM/SIRM and SIRM/X are corresponding to precipitation and temperature, respectively; 3 the Holocene Megathermal in the study area was identified as 7.5-3.4 cal. ka BP. The warmest stage of Holocene for the study area should be during 6.1 to 3.9 cal. ka BP; 4 The 8 ka cold event was characterized as cold and dry during 8.55 to 8.25 cal. ka BP; 5 During early and middle Holocene, the climate combinations were warm dry and cold wet. It turned to warm and wet after 2.7 cal. ka BP.

  18. Superimposing various biophysical and social scales in a rapidly changing rural area (SW Niger)

    Science.gov (United States)

    Leduc, Christian; Massuel, Sylvain; Favreau, Guillaume; Cappelaere, Bernard; Leblanc, Marc; Bachir, Salifou; Ousmane, Boureïma

    2014-05-01

    transboundary aquifer that extends far beyond the study area, over about 150 000 km2. It is also heterogeneous. Like surface flows, but at a different scale, groundwater flows are marked by a strong endorheism. For example the Dantiandou closed piezometric depression extends over about approximately 5000 km2. These natural closed depressions are explained only by evapotranspiration uptake, weak in absolute terms (a few mm.a-1) but with a very high impact on hydrodynamics because of poor permeability and porosity. Both density of observations and hydraulic continuity of the CT3 aquifer give a fine idea of groundwater changes in the whole area. Human activities, continuously adapting in this poor rural area, add another complexity to the hydrological diversity in surface and ground water. The replacement of the natural vegetation with millet fields and fallow increased the surface runoff, and consequently water accumulation in temporary pools and then CT3 recharge. In the SE part of the study area, the water table has risen up to outcropping in the lowest valley bottoms. These new permanent ponds reflect groundwater while temporary ponds still reflect surface dynamics. This new component of the hydrological landscape induces several consequences, in physical and human dimensions. Evaporation strongly affects the permanent water and increases its salinity while the natural mineralization of groundwater is very low. The easier access to water resources allows a significant development of local gardening, which modifies the social functioning of villages (e.g. land rights between villages and within a village, diversification of crops and sources of income, new sales channels). Different physically based models (for surface and ground water) were built, with a significant discrepancy between their respective quantification of water flows at the region scale. Extrapolation of surface fluxes from the few instrumented catchments to a much larger mosaic of non-instrumented catchments is

  19. Rapid Geophysical Surveyor

    International Nuclear Information System (INIS)

    Roybal, L.G.; Carpenter, G.S.; Josten, N.E.

    1993-01-01

    The Rapid Geophysical Surveyor (RGS) is a system designed to rapidly and economically collect closely-spaced geophysical data used for characterization of US Department of Energy waste sites. Geophysical surveys of waste sites are an important first step in the remediation and closure of these sites; especially older sites where historical records are inaccurate and survey benchmarks have changed because of refinements in coordinate controls and datum changes. Closely-spaced data are required to adequately differentiate pits, trenches, and soil vault rows whose edges may be only a few feet from each other. A prototype vehicle designed to collect magnetic field data was built at the Idaho National Engineering Laboratory (INEL) during the summer of 1992. The RGS was funded by the Buried Waste Integrated Demonstration program. This vehicle was demonstrated at the Subsurface Disposal Area (SDA) within the Radioactive Waste Management Complex at the INEL in September 1992. Magnetic data were collected over two areas in the SDA, with a total survey area of about 1.7 acres. Data were collected at a nominal density of 2 1/2 in. along survey lines spaced 1-ft apart. Over 350,000 data points were collected over a 6 day period corresponding to about 185 worker-days using conventional ground survey techniques

  20. MAGNET

    CERN Multimedia

    B. Curé

    2013-01-01

      The magnet was operated without any problem until the end of the LHC run in February 2013, apart from a CERN-wide power glitch on 10 January 2013 that affected the CMS refrigerator, causing a ramp down to 2 T in order to reconnect the coldbox. Another CERN-wide power glitch on 15 January 2013 didn’t affect the magnet subsystems, the cryoplant or the power converter. At the end of the magnet run, the reconnection of the coldbox at 2.5 T was tested. The process will be updated, in particular the parameters of some PID valve controllers. The helium flow of the current leads was reduced but only for a few seconds. The exercise will be repeated with the revised parameters to validate the automatic reconnection process of the coldbox. During LS1, the water-cooling services will be reduced and many interventions are planned on the electrical services. Therefore, the magnet cryogenics and subsystems will be stopped for several months, and the magnet cannot be kept cold. In order to avoid unc...

  1. MAGNET

    CERN Multimedia

    Benoit Curé

    2010-01-01

    The magnet was successfully operated at the end of the year 2009 despite some technical problems on the cryogenics. The magnet was ramped up to 3.8 T at the end of November until December 16th when the shutdown started. The magnet operation met a few unexpected stops. The field was reduced to 3.5 T for about 5 hours on December 3rd due to a faulty pressure sensor on the helium compressor. The following day the CERN CCC stopped unintentionally the power converters of the LHC and the experiments, triggering a ramp down that was stopped at 2.7 T. The magnet was back at 3.8 T about 6 hours after CCC sent the CERN-wide command. Three days later, a slow dump was triggered due to a stop of the pump feeding the power converter water-cooling circuit, during an intervention on the water-cooling plant done after several disturbances on the electrical distribution network. The magnet was back at 3.8 T in the evening the same day. On December 10th a break occurred in one turbine of the cold box producing the liquid ...

  2. MAGNET

    CERN Multimedia

    B. Curé

    2011-01-01

    The CMS magnet has been running steadily and smoothly since the summer, with no detected flaw. The magnet instrumentation is entirely operational and all the parameters are at their nominal values. Three power cuts on the electrical network affected the magnet run in the past five months, with no impact on the data-taking as the accelerator was also affected at the same time. On 22nd June, a thunderstorm caused a power glitch on the service electrical network. The primary water cooling at Point 5 was stopped. Despite a quick restart of the water cooling, the inlet temperature of the demineralised water on the busbar cooling circuit increased by 5 °C, up to 23.3 °C. It was kept below the threshold of 27 °C by switching off other cooling circuits to avoid the trigger of a slow dump of the magnet. The cold box of the cryogenics also stopped. Part of the spare liquid helium volume was used to maintain the cooling of the magnet at 4.5 K. The operators of the cryogenics quickly restarted ...

  3. High-Latitude Topside Ionospheric Vertical Electron Density Profile Changes in Response to Large Magnetic Storms

    Science.gov (United States)

    Benson, Robert F.; Fainberg, Joseph; Osherovich, Vladimir A.; Truhlik, Vladimir; Wang, Yongli; Bilitza, Dieter; Fung, Shing F.

    2016-01-01

    Large magnetic-storm-induced changes were detected in high-latitude topside vertical electron density profiles Ne(h) in a database of profiles and digital topside ionograms, from the International Satellites for Ionospheric Studies (ISIS) program, that enabled Ne(h) profiles to be obtained in nearly the same region of space before, during, and after a major magnetic storm (Dst -100nT). Storms where Ne(h) profiles were available in the high-latitude Northern Hemisphere had better coverage of solar wind parameters than storms with available Ne(h) profiles in the high-latitude Southern Hemisphere. Large Ne(h) changes were observed during all storms, with enhancements and depletions sometimes near a factor of 10 and 0.1, respectively, but with substantial differences in the responses in the two hemispheres. Large spatial andor temporal Ne(h) changes were often observed during Dst minimum and during the storm recovery phase. The storm-induced Ne(h) changes were the most pronounced and consistent in the Northern Hemisphere in that large enhancements were observed during winter nighttime and large depletions during winter and spring daytime. The limited available cases suggested that these Northern Hemisphere enhancements increased with increases of the time-shifted solar wind velocity v, magnetic field B, and with more negative values of the B components except for the highest common altitude (1100km) of the profiles. There was also some evidence suggesting that the Northern Hemisphere depletions were related to changes in the solar wind parameters. Southern Hemisphere storm-induced enhancements and depletions were typically considerably less with depletions observed during summer nighttime conditions and enhancements during summer daytime and fall nighttime conditions.

  4. Toward a mechanistic understanding of human-induced rapid environmental change: A case study linking energy development, avian nest predation, and predators

    Science.gov (United States)

    Hethcoat, Matthew G.; Chalfoun, Anna D.

    2015-01-01

    Demographic consequences of human-induced rapid environmental change (HIREC) have been widely documented for many populations. The mechanisms underlying such patterns, however, are rarely investigated and yet are critical to understand for effective conservation and management.

  5. Magnetic molecularly imprinted polymers based on silica modified by deep eutectic solvents for the rapid simultaneous magnetic-based solid-phase extraction of Salvia miltiorrhiza bunge, Glycine max (Linn.) Merr and green tea.

    Science.gov (United States)

    Li, Guizhen; Wang, Xiaoqin; Row, Kyung Ho

    2018-04-01

    Novel magnetic molecularly imprinted polymers (MMIPs) with multiple-template based on silica were modified by four types of deep eutectic solvents (DESs) for the rapid simultaneous magnetic solid-phase extraction (MSPE) of tanshinone Ⅰ, tanshinone ⅡA, and cryptotanshinone from Salvia miltiorrhiza bunge; glycitein, genistein, and daidzein from Glycine max (Linn.) Merr; and epicatechin, epigallocatechin gallate, and epicatechin gallate from green tea, respectively. The synthesized materials were characterized by Fourier transform infrared spectroscopy and field emission scanning electron microscopy. Single factor experiments were to explore the relationship between the extraction efficiency and four factors (the sample solution pH, amount of DESs for modification, amount of adsorbent, and extraction time). It was showed that the DES4-MMIPs have better extraction ability than the MMIPs without DESs and the other three DESs-modified MMIPs. The best extraction recoveries with DES4-MMIP were tanshinone Ⅰ (85.57%), tanshinone ⅡA (80.58%), cryptotanshinone (92.12%), glycitein (81.65%), genistein (87.72%), daidzein (92.24%), epicatechin (86.43%), epigallocatechin gallate (80.92%), and epicatechin gallate (93.64%), respectively. The novel multiple-template MMIPs materials modified by DES for the rapid simultaneous MSPE of active compounds were proved to reduce the experimental steps than single-template technique, and increase the extraction efficiency. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. A fibre optic oxygen sensor that detects rapid PO2 changes under simulated conditions of cyclical atelectasis in vitro.

    Science.gov (United States)

    Formenti, Federico; Chen, Rongsheng; McPeak, Hanne; Matejovic, Martin; Farmery, Andrew D; Hahn, Clive E W

    2014-01-15

    Two challenges in the management of Acute Respiratory Distress Syndrome are the difficulty in diagnosing cyclical atelectasis, and in individualising mechanical ventilation therapy in real-time. Commercial optical oxygen sensors can detect [Formula: see text] oscillations associated with cyclical atelectasis, but are not accurate at saturation levels below 90%, and contain a toxic fluorophore. We present a computer-controlled test rig, together with an in-house constructed ultra-rapid sensor to test the limitations of these sensors when exposed to rapidly changing [Formula: see text] in blood in vitro. We tested the sensors' responses to simulated respiratory rates between 10 and 60 breaths per minute. Our sensor was able to detect the whole amplitude of the imposed [Formula: see text] oscillations, even at the highest respiratory rate. We also examined our sensor's resistance to clot formation by continuous in vivo deployment in non-heparinised flowing animal blood for 24h, after which no adsorption of organic material on the sensor's surface was detectable by scanning electron microscopy. Copyright © 2013 The Authors. Published by Elsevier B.V. All rights reserved.

  7. Rapid detection of Prunus necrotic ringspot virus using magnetic nanoparticle-assisted reverse transcription loop-mediated isothermal amplification.

    Science.gov (United States)

    Zong, Xiaojuan; Wang, Wenwen; Wei, Hairong; Wang, Jiawei; Chen, Xin; Xu, Li; Zhu, Dongzi; Tan, Yue; Liu, Qingzhong

    2014-11-01

    Prunus necrotic ringspot virus (PNRSV) has seriously reduced the yield of Prunus species worldwide. In this study, a highly efficient and specific two-step reverse transcription loop-mediated isothermal amplification (RT-LAMP) was developed to detect PNRSV. Total RNA was extracted from sweet cherry leaf samples using a commercial kit based on a magnetic nanoparticle technique. Transcripts were used as the templates for the assay. The results of this assay can be detected using agarose gel electrophoresis or by assessing in-tube fluorescence after adding SYBR Green I. The assay is highly specific for PNRSV, and it is more sensitive than reverse-transcription polymerase chain reaction (RT-PCR). Restriction enzyme digestion verified further the reliability of this RT-LAMP assay. To our knowledge, this is the first report of the application of RT-LAMP to PNRSV detection in Prunus species. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Studies on entanglement entropy for Hubbard model with hole-doping and external magnetic field [rapid communication

    Science.gov (United States)

    Yao, K. L.; Li, Y. C.; Sun, X. Z.; Liu, Q. M.; Qin, Y.; Fu, H. H.; Gao, G. Y.

    2005-10-01

    By using the density matrix renormalization group (DMRG) method for the one-dimensional (1D) Hubbard model, we have studied the von Neumann entropy of a quantum system, which describes the entanglement of the system block and the rest of the chain. It is found that there is a close relation between the entanglement entropy and properties of the system. The hole-doping can alter the charge charge and spin spin interactions, resulting in charge polarization along the chain. By comparing the results before and after the doping, we find that doping favors increase of the von Neumann entropy and thus also favors the exchange of information along the chain. Furthermore, we calculated the spin and entropy distribution in external magnetic filed. It is confirmed that both the charge charge and the spin spin interactions affect the exchange of information along the chain, making the entanglement entropy redistribute.

  9. Rapid Determination of Trace Palladium in Active Pharmaceutical Ingredients by Magnetic Solid-Phase Extraction and Flame Atomic Absorption Spectrometry

    Science.gov (United States)

    Yin, Q. H.; Zhu, D. M.; Yang, D. Z.; Hu, Q. F.; Yang, Y. L.

    2018-01-01

    Clutaraldehyde cross-linked magnetic chitosan nanoparticles were synthesized and used as an adsorbent for the dispersive solid-phase extraction of palladium in active pharmaceutical ingredients (APIs) prior to analysis by a flame atomic absorption spectrophotometer. FT-IR, X-ray diffraction, and TEM were used to characterize the adsorbent. Various parameters of experimental performance, such as adsorbent amount, pH, adsorption time, desorption solutions, coexisting ions, and adsorbent reusability, were investigated and optimized. Under the optimized conditions, good linearity was achieved in the 5.0-500 μg/L concentration range, with correlation coefficients of 0.9989. The limit of detection is 2.8 μg/L and the recoveries of spiked samples ranged from 91.7 to 97.6%. It was confirmed that the GMCNs nanocomposite was a promising adsorbing material for extraction and preconcentration of Pd in APIs.

  10. Threshold and resilience management of coupled urbanization and water environmental system in the rapidly changing coastal region.

    Science.gov (United States)

    Li, Yangfan; Li, Yi; Wu, Wei

    2016-01-01

    The concept of thresholds shows important implications for environmental and resource management. Here we derived potential landscape thresholds which indicated abrupt changes in water quality or the dividing points between exceeding and failing to meet national surface water quality standards for a rapidly urbanizing city on the Eastern Coast in China. The analysis of landscape thresholds was based on regression models linking each of the seven water quality variables to each of the six landscape metrics for this coupled land-water system. We found substantial and accelerating urban sprawl at the suburban areas between 2000 and 2008, and detected significant nonlinear relations between water quality and landscape pattern. This research demonstrated that a simple modeling technique could provide insights on environmental thresholds to support more-informed decision making in land use, water environmental and resilience management. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. The importance of the sampling frequency in determining short-time-averaged irradiance and illuminance for rapidly changing cloud cover

    International Nuclear Information System (INIS)

    Delaunay, J.J.; Rommel, M.; Geisler, J.

    1994-01-01

    The sampling interval is an important parameter which must be chosen carefully, if measurements of the direct, global, and diffuse irradiance or illuminance are carried out to determine their averages over a given period. Using measurements from a day with rapidly moving clouds, we investigated the influence of the sampling interval on the uncertainly of the calculated 15-min averages. We conclude, for this averaging period, that the sampling interval should not exceed 60 s and 10 s for measurement of the diffuse and global components respectively, to reduce the influence of the sampling interval below 2%. For the direct component, even a 5 s sampling interval is too long to reach this influence level for days with extremely quickly changing insolation conditions. (author)

  12. Dryland responses to global change suggest the potential for rapid non-linear responses to some changes but resilience to others

    Science.gov (United States)

    Reed, S.; Ferrenberg, S.; Tucker, C.; Rutherford, W. A.; Wertin, T. M.; McHugh, T. A.; Morrissey, E.; Kuske, C.; Belnap, J.

    2017-12-01

    Drylands represent our planet's largest terrestrial biome, making up over 35% of Earth's land surface. In the context of this vast areal extent, it is no surprise that recent research suggests dryland inter-annual variability and responses to change have the potential to drive biogeochemical cycles and climate at the global-scale. Further, the data we do have suggest drylands can respond rapidly and non-linearly to change. Nevertheless, our understanding of the cross-system consistency of and mechanisms behind dryland responses to a changed environment remains relatively poor. This poor understanding hinders not only our larger understanding of terrestrial ecosystem function, but also our capacity to forecast future global biogeochemical cycles and climate. Here we present data from a series of Colorado Plateau manipulation experiments - including climate, land use, and nitrogen deposition manipulations - to explore how vascular plants, microbial communities, and biological soil crusts (a community of mosses, lichens, and/or cyanobacteria living in the interspace among vascular plants in arid and semiarid ecosystems worldwide) respond to a host of environmental changes. These responses include not only assessments of community composition, but of their function as well. We will explore photosynthesis, net soil CO2 exchange, soil carbon stocks and chemistry, albedo, and nutrient cycling. The experiments were begun with independent questions and cover a range of environmental change drivers and scientific approaches, but together offer a relatively holistic picture of how some drylands can change their structure and function in response to change. In particular, the data show very high ecosystem vulnerability to particular drivers, but surprising resilience to others, suggesting a multi-faceted response of these diverse systems.

  13. Alteration of chromophoric dissolved organic matter by solar UV radiation causes rapid changes in bacterial community composition†

    Science.gov (United States)

    Piccini, Claudia; Conde, Daniel; Pernthaler, Jakob; Sommaruga, Ruben

    2010-01-01

    We evaluated the effect of photochemical alterations of chromophoric dissolved organic matter (CDOM) on bacterial abundance, activity and community composition in a coastal lagoon of the Atlantic Ocean with high dissolved organic carbon concentration. On two occasions during the austral summer, bacteria-free water of the lagoon was exposed to different regions of the solar spectrum (full solar radiation, UV-A + PAR, PAR) or kept in the dark. Subsequently, dilution cultures were established with bacterioplankton from the lagoon that were incubated in the pre-exposed water for 5 h in the dark. Cell abundance, activity, and community composition of bacterioplankton were assessed before and after incubation in the different treatments. Changes in absorption, fluorescence, and DOC concentration were used as proxies for CDOM photoalteration. We found a significant CDOM photobleaching signal, DOC loss, as well as a stimulation of bacterial activity in the treatments pre-exposed to UV radiation, suggesting increased bioavailability of DOM. Bacterial community analysis by fluorescence in situ hybridization revealed that this stimulation was mainly accompanied by the specific enrichment of Alpha- and Betaproteobacteria. Thus, our results suggest that CDOM photoalteration not only stimulates bacterioplankton growth, but also induces rapid changes in bacterioplankton composition, which can be of relevance for ecosystem functioning, particularly considering present and future changes in the input of terrestrial CDOM to aquatic systems. PMID:19707620

  14. Alteration of chromophoric dissolved organic matter by solar UV radiation causes rapid changes in bacterial community composition.

    Science.gov (United States)

    Piccini, Claudia; Conde, Daniel; Pernthaler, Jakob; Sommaruga, Ruben

    2009-09-01

    We evaluated the effect of photochemical alterations of chromophoric dissolved organic matter (CDOM) on bacterial abundance, activity and community composition in a coastal lagoon of the Atlantic Ocean with high dissolved organic carbon concentration. On two occasions during the austral summer, bacteria-free water of the lagoon was exposed to different regions of the solar spectrum (full solar radiation, UV-A+PAR, PAR) or kept in the dark. Subsequently, dilution cultures were established with bacterioplankton from the lagoon that were incubated in the pre-exposed water for 5 h in the dark. Cell abundance, activity, and community composition of bacterioplankton were assessed before and after incubation in the different treatments. Changes in absorption, fluorescence, and DOC concentration were used as proxies for CDOM photoalteration. We found a significant CDOM photobleaching signal, DOC loss, as well as a stimulation of bacterial activity in the treatments pre-exposed to UV radiation, suggesting increased bioavailability of DOM. Bacterial community analysis by fluorescence in situ hybridization revealed that this stimulation was mainly accompanied by the specific enrichment of Alpha- and Betaproteobacteria. Thus, our results suggest that CDOM photoalteration not only stimulates bacterioplankton growth, but also induces rapid changes in bacterioplankton composition, which can be of relevance for ecosystem functioning, particularly considering present and future changes in the input of terrestrial CDOM to aquatic systems.

  15. Multi-generational responses of a marine polychaete to a rapid change in seawater pCO2.

    Science.gov (United States)

    Rodríguez-Romero, Araceli; Jarrold, Michael D; Massamba-N'Siala, Gloria; Spicer, John I; Calosi, Piero

    2016-10-01

    Little is known of the capacity that marine metazoans have to evolve under rapid p CO 2 changes. Consequently, we reared a marine polychaete, Ophryotrocha labronica , previously cultured for approximately 33 generations under a low/variable pH regime, under elevated and low p CO 2 for six generations. The strain used was found to be tolerant to elevated p CO 2 conditions. In generations F1 and F2 females' fecundity was significantly lower in the low p CO 2 treatment. However, from generation F3 onwards there were no differences between p CO 2 treatments, indicating that trans-generational effects enabled the restoration and maintenance of reproductive output. Whilst the initial fitness recovery was likely driven by trans-generational plasticity (TGP), the results from reciprocal transplant assays, performed using F7 individuals, made it difficult to disentangle between whether TGP had persisted across multiple generations, or if evolutionary adaptation had occurred. Nonetheless, both are important mechanisms for persistence under climate change. Overall, our study highlights the importance of multi-generational experiments in more accurately determining marine metazoans' responses to changes in p CO 2 , and strengthens the case for exploring their use in conservation, by creating specific p CO 2 tolerant strains of keystone ecosystem species.

  16. Specialists meeting on design and assessment of instrumentation and control systems in NPP coping with rapid technological change

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-10-01

    A transition from analogue to computer based I and C (instrumentation and control) systems in nuclear power plants enabled the industry not only to make use of advantages of computers for the control of technological processes, but also transferred the unusual short innovation cycles in computer technology to become a constraint on the process I and C. This situation led the IAEA to provide an international forum for the presentation and discussion of the problems and organize a Specialists` Meeting in the framework of the International Working Group on Nuclear Power Plant Control and Instrumentation. The basic objective was to elaborate the management, engineering and economic problems arising from rapid technological changes, to point out solutions and to discuss the future trends in the field. The Year 2000 Issue was also inside the scope of the Meeting. Typical problems were technology changes provoking major I and C concept changes, spare part availability, compatibility in refurbishment processes. The present document contains the papers presented by national delegates, each with an abstract, and the conclusions drawn from the final discussion Refs, figs, tabs

  17. Specialists meeting on design and assessment of instrumentation and control systems in NPP coping with rapid technological change

    International Nuclear Information System (INIS)

    1998-10-01

    A transition from analogue to computer based I and C (instrumentation and control) systems in nuclear power plants enabled the industry not only to make use of advantages of computers for the control of technological processes, but also transferred the unusual short innovation cycles in computer technology to become a constraint on the process I and C. This situation led the IAEA to provide an international forum for the presentation and discussion of the problems and organize a Specialists' Meeting in the framework of the International Working Group on Nuclear Power Plant Control and Instrumentation. The basic objective was to elaborate the management, engineering and economic problems arising from rapid technological changes, to point out solutions and to discuss the future trends in the field. The Year 2000 Issue was also inside the scope of the Meeting. Typical problems were technology changes provoking major I and C concept changes, spare part availability, compatibility in refurbishment processes. The present document contains the papers presented by national delegates, each with an abstract, and the conclusions drawn from the final discussion

  18. Ecological ethics in captivity: balancing values and responsibilities in zoo and aquarium research under rapid global change.

    Science.gov (United States)

    Minteer, Ben A; Collins, James P

    2013-01-01

    Ethical obligations to animals in conservation research and management are manifold and often conflicting. Animal welfare concerns often clash with the ethical imperative to understand and conserve a population or ecosystem through research and management intervention. The accelerating pace and impact of global environmental change, especially climate change, complicates our understanding of these obligations. One example is the blurring of the distinction between ex situ (zoo- and aquarium-based) conservation and in situ (field-based) approaches as zoos and aquariums become more active in field conservation work and as researchers and managers consider more intensive interventions in wild populations and ecosystems to meet key conservation goals. These shifts, in turn, have consequences for our traditional understanding of the ethics of wildlife research and management, including our relative weighting of animal welfare and conservation commitments across rapidly evolving ex situ and in situ contexts. Although this changing landscape in many ways supports the increased use of captive wildlife in conservation-relevant research, it raises significant ethical concerns about human intervention in populations and ecosystems, including the proper role of zoos and aquariums as centers for animal research and conservation in the coming decades. Working through these concerns requires a pragmatic approach to ethical analysis, one that is able to make trade-offs among the many goods at stake (e.g., animal welfare, species viability, and ecological integrity) as we strive to protect species from further decline and extinction in this century.

  19. Influence of rapid changes in cytosolic pH on oxidative phosphorylation in skeletal muscle: theoretical studies.

    Science.gov (United States)

    Korzeniewski, Bernard; Zoladz, Jerzy A

    2002-07-01

    Cytosolic pH in skeletal muscle may vary significantly because of proton production/consumption by creatine kinase and/or proton production by anaerobic glycolysis. A computer model of oxidative phosphorylation in intact skeletal muscle developed previously was used to study the kinetic effect of these variations on the oxidative phosphorylation system. Two kinds of influence were analysed: (i) via the change in pH across the inner mitochondrial membrane and (ii) via the shift in the equilibrium of the creatine kinase-catalysed reaction. Our simulations suggest that cytosolic pH has essentially no impact on the steady-state fluxes and most metabolite concentrations. On the other hand, rapid acidification/alkalization of cytosol causes a transient decrease/increase in the respiration rate. Furthermore, changes in pH seem to affect significantly the kinetic properties of transition between resting state and active state. An increase in pH brought about by proton consumption by creatine kinase at the onset of exercise lengthens the transition time. At intensive exercise levels this pH increase could lead to loss of the stability of the system, if not compensated by glycolytic H+ production. Thus our theoretical results stress the importance of processes/mechanisms that buffer/compensate for changes in cytosolic proton concentration. In particular, we suggest that the second main role of anaerobic glycolysis, apart from additional ATP supply, may be maintaining the stability of the system at intensive exercise.

  20. Changes in Earth's core-generated magnetic field, as observed by Swarm

    DEFF Research Database (Denmark)

    Finlay, Chris; Olsen, Nils; Gillet, Nicolas

    By far the largest part of the Earth's magnetic field is generated by motions taking place within our planet's liquid metal outer core. Variations of this core-generated field thus provide us with a unique means of probing the dynamics taking place in the deepest reaches of the Earth....... In this contribution, we will present the core-generated magnetic field, and its recent time changes, as seen by ESA's Earth explorer mission Swarm. We will present a new time-dependent geomagnetic field model, called CHAOS-6, derived from satellite data collected by the Swarm constellation, as well as data from...... the previous missions CHAMP and Oersted together with ground observatory data. Advantage is taken of the constellation aspect of the Swarm mission by ingesting field differences along track and across track between the lower pair of Swarm satellites. Evaluating the global field model at the outer boundary...

  1. Environmental influences on the at-sea behaviour of a major consumer, Mirounga leonina, in a rapidly changing environment

    Directory of Open Access Journals (Sweden)

    Trevor McIntyre

    2014-11-01

    Full Text Available Understanding the distribution and foraging ecology of major consumers within pelagic systems, specifically in relation to physical parameters, can be important for the management of bentho-pelagic systems undergoing rapid change associated with global climate change and other anthropogenic disturbances such as fishing (i.e., the Antarctic Peninsula and Scotia Sea. We tracked 11 adult male southern elephant seals (Mirounga leonina, during their five-month post-moult foraging migrations from King George Island (Isla 25 de Mayo, northern Antarctic Peninsula, using tags capable of recording and transmitting behavioural data and in situ temperature and salinity data. Seals foraged mostly within the Weddell–Scotia Confluence, while a few foraged along the western Antarctic Peninsula shelf of the Bellingshausen Sea. Mixed model outputs suggest that the at-sea behaviour of seals was associated with a number of environmental parameters, especially seafloor depth, sea-ice concentrations and the temperature structure of the water column. Seals increased dive bottom times and travelled at slower speeds in shallower areas and areas with increased sea-ice concentrations. Changes in dive depth and durations, as well as relative amount of time spent during the bottom phases of dives, were observed in relation to differences in overall temperature gradient, likely as a response to vertical changes in prey distribution associated with temperature stratification in the water column. Our results illustrate the likely complex influences of bathymetry, hydrography and sea ice on the behaviour of male southern elephant seals in a changing environment and highlight the need for region-specific approaches to studying environmental influences on behaviour.

  2. Rapid structural and compositional change in an old-growth subtropical forest: using plant traits to identify probable drivers.

    Science.gov (United States)

    Malizia, Agustina; Easdale, Tomás A; Grau, H Ricardo

    2013-01-01

    Recent studies have shown directional changes in old-growth tropical forests, but changes are complex and diverse, and their drivers unclear. Here, we report rapid net structural and compositional changes in an old-growth subtropical forest and we assess the functional nature of these changes to test hypothetical drivers including recovery from past disturbances, reduction in ungulate browsing, CO2 fertilization, and increases in rainfall and temperature. The study relies on 15 years of demographic monitoring within 8 ha of subtropical montane forest in Argentina. Between 1992 and 2007, stem density markedly increased by 50% (12 stems ha(-1) y(-1)) and basal area by 6% (0.13 m(2) ha(-1) y(-1)). Increased stem density resulted from enhanced recruitment of understory treelets (Piper tucumanum, Eugenia uniflora, Allophylus edulis) into small size classes. Among 27 common tree species, net population growth was negatively correlated with maximum tree size and longevity, and positively correlated with leaf size and leaf nutrient content, especially so when initial population size was controlled for. Changes were inconsistent with predictions derived from past disturbances (no increase in shade-tolerant or long-lived late-succesional species), rainfall or temperature increase (no increase in evergreen or deciduous species, respectively). However, the increase in nutrient-rich soft-leaved species was consistent with exclusion of large herbivores two decades before monitoring started; and CO2 fertilization could help explain the disproportionate increase in small stems. Reductions in populations of large vertebrates have been observed in many otherwise undisturbed tropical forests, and our results suggest they can have important structural and functional repercussions in these forests.

  3. Changes in occlusal relationships in mixed dentition patients treated with rapid maxillary expansion. A prospective clinical study.

    Science.gov (United States)

    McNamara, James A; Sigler, Lauren M; Franchi, Lorenzo; Guest, Susan S; Baccetti, Tiziano

    2010-03-01

    To prospectively measure occlusal changes in mixed dentition patients who underwent a standardized early expansion protocol. The treatment sample consisted of 500 patients who were assigned to three groups according to molar relationship: Class I (n = 204), end-to-end (n = 166), and Class II (n = 130). All patients were treated with a bonded rapid maxillary expander (RME) followed by a removable maintenance plate and a transpalatal arch. Mean age at the start of treatment was 8.8 years (T(1)), with a pre-phase 2 treatment cephalogram (T(2)) taken 3.7 years later. The control sample consisted of the cephalometric records of 188 untreated subjects (Class 1, n = 79; end-to-end, n = 51; Class II, n = 58). The largest change in molar relationship was noted when the Class II treatment group (1.8 mm) was compared with the matched control group (0.3 mm). A positive change was seen in 81% of the Class II treatment group, with almost half of the group improving by > or = 2.0 mm. The end-to-end treatment group had a positive change of 1.4 mm, compared with a control value of 0.6 mm, and the Class I group of about 1 mm compared with controls, who remained unchanged (0.1 mm). Skeletal changes were not significant when any of the groups were compared with controls. The expansion protocol had a significantly favorable effect on the sagittal occlusal relationships of Class II, end-to-end, and Class I patients treated in the early mixed dentition.

  4. National Uranium Resource Evaluation. Aerial gamma ray and magnetic survey, Racine and Grand Rapids quadrangles, Michigan, Wisconsin and Illinois. Final report

    International Nuclear Information System (INIS)

    1981-07-01

    The Racine and Grand Rapids quadrangles of southeastern Wisconsin, northeastern Illinois, and Michigan cover a land area of 8785 square miles, and an additional water surface area of 5215 square miles. In the northeast, thick Paleozoic deposits overlie a regional downwarp of the Precambrian basement called the Michigan Basin. These Paleozoic deposits shoal to only 500 feet in the southwest corner of the survey area. The entire region is covered by a mantle of Quaternary glacial material. A search of available literature revealed no economically feasible uranium deposits. A total of 83 uranium anomalies were detected and are discussed briefly. All appear to have cultural, and/or locally unsaturated associations, and none appear to contain significant measured quantities of uranium. Magnetic data appear to be in general agreement with existing structural interpretations of the area. There are local exceptions which suggest some lithologic and/or structural complexities in the basement material

  5. MAGNET

    CERN Multimedia

    B. Curé

    2011-01-01

    The magnet ran smoothly in the last few months until a fast dump occurred on 9th May 2011. Fortunately, this occurred in the afternoon of the first day of the technical stop. The fast dump was due to a valve position controller that caused the sudden closure of a valve. This valve is used to regulate the helium flow on one of the two current leads, which electrically connects the coil at 4.5 K to the busbars at room temperature. With no helium flow on the lead, the voltage drop and the temperatures across the leads increase up to the defined thresholds, triggering a fast dump through the Magnet Safety System (MSS). The automatic reaction triggered by the MSS worked properly. The helium release was limited as the pressure rise was just at the limit of the safety valve opening pressure. The average temperature of the magnet reached 72 K. It took four days to recover the temperature and refill the helium volumes. The faulty valve controller was replaced by a spare one before the magnet ramp-up resumed....

  6. CHANGE OF CONNECTION BETWEEN MAGNETIC PARAMETERS OF CAST IRON IN COMPARISON WITH STEEL UNDER INFLUENCE OF INTERNAL DEMAGNETIZATION

    Directory of Open Access Journals (Sweden)

    S. G. Sandomirsky

    2014-01-01

    Full Text Available Connection of maximum magnetic permeability µm of cast irons with coercive force Нс and residual magnetism Мr is established in all size of changing of the magnetic characteristics of cast iron. Differences of this connection for steels and cast irons are revealed. Formula for calculation µm of steels by Нс and Мr is corrected for calculation µm of cast irons. As a result of correction the calculation error of cast irons µm is diminished. The results can be used in magnetic structural analysis instead of labor-consuming measurement µm.

  7. Magnetic bead/capture DNA/glucose-loaded nanoliposomes for amplifying the glucometer signal in the rapid screening of hepatitis C virus RNA.

    Science.gov (United States)

    Tu, Haijian; Lin, Kun; Lun, Yongzhi; Yu, Liuming

    2018-06-01

    A digital detection strategy based on a portable personal glucometer (PGM) was developed for the simple, rapid, and sensitive detection of hepatitis C virus (HCV) RNA, involving the release of glucose-loaded nanoliposomes due to coupling-site-specific cleavage by the endonuclease BamHI. The glucose-loaded nanoliposomes were synthesized using a reversed-phase evaporation method and provided an amplified signal at the PGM in the presence of HCV RNA. Initially, a 21-mer oligonucleotide complementary to HCV RNA was covalently conjugated to a magnetic bead through the amino group at the 5' end of the oligonucleotide, and then bound to a glucose-loaded liposome by typical carbodiimide coupling at its 3' end. In the presence of the target HCV RNA, the target hybridized with the oligonucleotide to form double-stranded DNA. The symmetrical duplex sequence 5'-GGATCC-3' between guanines was then catalytically cleaved by BamHI, which detached the glucose-loaded liposome from the magnetic bead. Following magnetic separation of the bead, the detached glucose-loaded liposome was lysed using Triton X-100 to release the glucose molecules within it, which were then detected as an amplified signal at the digital PGM. Under optimal conditions, the PGM signal increased with increasing HCV RNA, and displayed a strongly linear dependence on the level of HCV RNA for concentrations ranging from 10 pM to 1.0 μM. The detection limit (LOD) of the system was 1.9 pM. Good reproducibility and favorable specificity were achieved in the analysis of the target HCV RNA. Human serum samples containing HCV RNA were analyzed using this strategy, and the developed sensing platform was observed to yield satisfactory results based on a comparison with the corresponding results from a Cobas ® Amplicor HCV Test Analyzer. Graphical abstract A digital detection strategy utilizing a personal glucometer was developed for the detection of hepatitis C virus RNA. The strategy involved the use of the

  8. Light-induced changes of cubic and uniaxial magnetic aniosotropy in a magnet doped by strongly anisotropic ions

    Czech Academy of Sciences Publication Activity Database

    Zaytseva, I.; Stupakiewicz, A.; Maziewski, A.; Zablotskyy, Vitaliy A.

    254-255, - (2003), s. 118-120 ISSN 0304-8853. [Soft Magnetic Material Conference ( SMM 15). Bilbao, 05.09.2001-07.09.2001] Institutional research plan: CEZ:AV0Z1010914 Keywords : photomagnetic effects * light-induced anisotropy * garnets Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.910, year: 2003

  9. Rapid time-resolved magnetic resonance angiography via a multiecho radial trajectory and GraDeS reconstruction.

    Science.gov (United States)

    Lee, Gregory R; Seiberlich, Nicole; Sunshine, Jeffrey L; Carroll, Timothy J; Griswold, Mark A

    2013-02-01

    Contrast-enhanced magnetic resonance angiography is challenging due to the need for both high spatial and temporal resolution. A multishot trajectory composed of pseudo-random rotations of a single multiecho radial readout was developed. The trajectory is designed to give incoherent aliasing artifacts and a relatively uniform distribution of projections over all time scales. A field map (computed from the same data set) is used to avoid signal dropout in regions of substantial field inhomogeneity. A compressed sensing reconstruction using the GraDeS algorithm was used. Whole brain angiograms were reconstructed at 1-mm isotropic resolution and a 1.1-s frame rate (corresponding to an acceleration factor > 100). The only parameter which must be chosen is the number of iterations of the GraDeS algorithm. A larger number of iterations improves the temporal behavior at cost of decreased image signal-to-noise ratio. The resulting images provide a good depiction of the cerebral vasculature and have excellent arterial/venous separation. Copyright © 2012 Wiley Periodicals, Inc.

  10. Niche tracking and rapid establishment of distributional equilibrium in the house sparrow show potential responsiveness of species to climate change.

    Directory of Open Access Journals (Sweden)

    William B Monahan

    Full Text Available The ability of species to respond to novel future climates is determined in part by their physiological capacity to tolerate climate change and the degree to which they have reached and continue to maintain distributional equilibrium with the environment. While broad-scale correlative climatic measurements of a species' niche are often described as estimating the fundamental niche, it is unclear how well these occupied portions actually approximate the fundamental niche per se, versus the fundamental niche that exists in environmental space, and what fitness values bounding the niche are necessary to maintain distributional equilibrium. Here, we investigate these questions by comparing physiological and correlative estimates of the thermal niche in the introduced North American house sparrow (Passer domesticus. Our results indicate that occupied portions of the fundamental niche derived from temperature correlations closely approximate the centroid of the existing fundamental niche calculated on a fitness threshold of 50% population mortality. Using these niche measures, a 75-year time series analysis (1930-2004 further shows that: (i existing fundamental and occupied niche centroids did not undergo directional change, (ii interannual changes in the two niche centroids were correlated, (iii temperatures in North America moved through niche space in a net centripetal fashion, and consequently, (iv most areas throughout the range of the house sparrow tracked the existing fundamental niche centroid with respect to at least one temperature gradient. Following introduction to a new continent, the house sparrow rapidly tracked its thermal niche and established continent-wide distributional equilibrium with respect to major temperature gradients. These dynamics were mediated in large part by the species' broad thermal physiological tolerances, high dispersal potential, competitive advantage in human-dominated landscapes, and climatically induced

  11. Magnetic covalent triazine framework for rapid extraction of phthalate esters in plastic packaging materials followed by gas chromatography-flame ionization detection.

    Science.gov (United States)

    Yan, Zijun; He, Man; Chen, Beibei; Gui, Bo; Wang, Cheng; Hu, Bin

    2017-11-24

    Covalent triazine frameworks (CTFs), featuring with high surface area, good thermal, chemical and mechanical stability, are good adsorbents in sample pretreatment. Herein, magnetic CTFs/Ni composite was prepared by in situ reduction of nickel ions on CTFs matrix with a solvothermal method. The prepared CTFs/Ni composite exhibited good preparation reproducibility, high chemical stability, and high extraction efficiency for targeted phthalate esters (PAEs) due to π-π interaction and hydrophobic effect. The porous structure of CTFs/Ni composite benefited the fast transfer of target PAEs from aqueous solution to the adsorbents, and the integrated magnetism contributed to the rapid separation of adsorbents from sample and elution solution. Based on it, a novel method of magnetic solid phase extraction (MSPE) combined with gas chromatography-flame ionization detector (GC-FID) was developed for the analysis of PAEs including dimethyl phthalate (DMP), diethyl phthalate (DEP), di-n-butyl phthalate (DBP), benzyl butyl phthalate (BBP), di-2-ethylhexl phthalate (DEHP), and di-n-octyl phthalate (DNOP) in plastic packaging materials. Under the optimal experimental conditions, the limits of detection (LODs, S/N=3) for six PAEs were found to be in the range of 0.024-0.085mg/kg. The linear range was 0.32-16mg/kg for DMP, DEP, 0.08-80mg/kg for DBP, 0.16-32mg/kg for BBP, DEHP, and 0.32-32mg/kg for DNOP, respectively. The enrichment factors ranged from 59 to 88-fold (theoretical enrichment factor was 133-fold). The proposed method was successfully applied to the analysis of PAEs in various plastic packaging materials with recoveries in the range of 70.6-119% for the spiked samples. This method is characterized with short operation time, high sensitivity, low consumption of harmful organic solvents and can be extended to the analysis of other trace aromatic compounds. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Rapid geophysical surveyor

    International Nuclear Information System (INIS)

    Roybal, L.G.; Carpenter, G.S.; Josten, N.E.

    1993-01-01

    The Rapid Geophysical Surveyor (RGS) is a system designed to rapidly and economically collect closely-spaced geophysical data used for characterization of Department of Energy (DOE) waste sites. Geophysical surveys of waste sites are an important first step in the remediation and closure of these sites; especially older sties where historical records are inaccurate and survey benchmarks have changed due to refinements in coordinate controls and datum changes. Closely-spaced data are required to adequately differentiate pits, trenches, and soil vault rows whose edges may be only a few feet from each other. A prototype vehicle designed to collect magnetic field data was built at the Idaho national Engineering Laboratory (INEL) during the summer of 1992. The RGS was one of several projects funded by the Buried Waste Integrated Demonstration (BWID) program. This vehicle was demonstrated at the Subsurface Disposal Area (SDA) within the Radioactive Waste Management Complex (RWMC) on the INEL in September of 1992. Magnetic data were collected over two areas in the SDA, with a total survey area of about 1.7 acres. Data were collected at a nominal density of 2 1/2 inches along survey lines spaced 1 foot apart. Over 350,000 data points were collected over a 6 day period corresponding to about 185 man-days using conventional ground survey techniques. This report documents the design and demonstration of the RGS concept including the presentation of magnetic data collected at the SDA. The surveys were able to show pit and trench boundaries and determine details of their spatial orientation never before achieved

  13. THE TOPOLOGICAL CHANGES OF SOLAR CORONAL MAGNETIC FIELDS. II. THE RECLOSING OF AN OPENED FIELD

    International Nuclear Information System (INIS)

    Low, B. C.; Janse, A. M.

    2009-01-01

    This is a study of the spontaneous formation of current sheets responding to the closing of an opened magnetic field by resistive reconnection in an electrically, highly conducting atmosphere outside a unit sphere. Pairs of initial-final equilibrium states are calculated explicitly, taking the field to be composed of three systems of untwisted flux in both states. In the initial state, two of the three flux systems are closed potential fields whereas the third system contains an equilibrium current sheet that keeps the potential fields on its two sides globally open. The final state is an everywhere potential field, with all three flux systems closed, produced by the resistive dissipation of the current sheet in the initial state. The unit sphere is taken to be a rigid, perfectly conducting wall during reconnection, so that the normal flux distribution is unchanged on the unit sphere. Field solutions subject to this unchanging boundary condition are obtained with and without the assumption of axisymmetry. The mathematical model has been designed to show that the topological changes produced by the current-sheet dissipation are simple under axisymmetry but radically different in the absence of axisymmetry, a fundamental point established in the first paper of this series. In the general case, the topological changes imply that other current sheets must have formed. Some of these current sheets form on the separatrix flux surfaces of the multipolar field. Others form throughout the closed-flux systems induced by volumetric changes. The opening and reclosing of magnetic fields during a solar coronal mass ejection may produce a multitude of current sheets not previously anticipated in the current understanding of this phenomenon. Basic to this study is a general topological property of magnetic flux tubes treated separately in the Appendix.

  14. The Arctic Report Card: Communicating the State of the Rapidly Changing Arctic to a Diverse Audience via the Worldwide Web

    Science.gov (United States)

    Jeffries, M. O.; Richter-Menge, J.; Overland, J. E.; Soreide, N. N.

    2013-12-01

    Rapid change is occurring throughout the Arctic environmental system. The goal of the Arctic Report Card is to communicate the nature of the many changes to a diverse audience via the Worldwide Web. First published in 2006, the Arctic Report Card is a peer-reviewed publication containing clear, reliable and concise scientific information on the current state of the Arctic environment relative to observational records. Available only online, it is intended to be an authoritative source for scientists, teachers, students, decision-makers, policy-makers and the general public interested in the Arctic environment and science. The Arctic Report Card is organized into five sections: Atmosphere; Sea Ice & Ocean; Marine Ecosystem; Terrestrial Ecosystem; Terrestrial Cryosphere. Arctic Report Card 2012, the sixth annual update, comprised 20 essays on physical and biological topics prepared by an international team of 141 scientists from 15 different countries. For those who want a quick summary, the Arctic Report Card home page provides highlights of key events and findings, and a short video that is also available on YouTube. The release of the Report Card each autumn is preceded by a NOAA press release followed by a press conference, when the Web site is made public. The release of Arctic Report Card 2012 at an AGU Fall Meeting press conference on 5 December 2012 was subsequently reported by leading media organizations. The NOAA Arctic Web site, of which the Report Card is a part, is consistently at the top of Google search results for the keyword 'arctic', and the Arctic Report Card Web site tops search results for keyword "arctic report" - pragmatic indications of a Web site's importance and popularity. As another indication of the Web site's impact, in December 2012, the month when the 2012 update was released, the Arctic Report Card Web site was accessed by 19,851 unique sites in 105 countries, and 4765 Web site URLs referred to the Arctic Report Card. The 2012 Arctic

  15. A 1200-Year Record of Rapid Climate Changes Across the Tropical Americas Identified from Lake Sediments (Invited)

    Science.gov (United States)

    Abbott, M.; Rodbell, D. T.; Stansell, N.; Bird, B. W.; Vuille, M.

    2009-12-01

    Well-dated, highly resolved lake sediment stratigraphies from similar catchments across the tropical Americas provide a means to investigate the timing, rate and direction of climate variability as well as providing a way to evaluate whether rapid changes occur synchronously in both hemispheres. This presentation focuses on the last 1500 years from three new high-resolution stable isotope records including Yuraicocha (12°32'S, 75°29'W), Pumacocha (10°41'S, 76° 3'36W), and Gancho (8°27'N, 80°51'W). These lakes are all sensitive to changes in P/E and the sediment records respond at subdecadal timescales. Additionally, the results from these sites are compared with lake level records from Titicaca (16°14'S, 68°37'W) and Blanca (8°19'N, 71°46'W) as well as other lake core and speleothem records from the region. The results show that in general conditions are dry across South America from ~800 AD until ~1300 AD with wetter conditions in Central America and the Caribbean. This pattern of dry conditions in tropical South America and wet conditions in the north reverses after ~1300 when conditions become wetter in South America, and drier in Central America and the Carrabin.

  16. Rapid Cultural Change: A Case Study of Polyandry Marriage System among the Gurung Community from Upper Mustang, Nepal

    Directory of Open Access Journals (Sweden)

    Juddha Bahadur Gurung

    2013-08-01

    Full Text Available Nepal is multi ethnic, multi lingual and multi cultural country. In Upper Mustang polyandry is practiced by Loba communities. However, the condition of polyandry is dying out at present. The young are not in favor of this system. Socio-economic, political, seasonal migration, tourism and developmental factors have played crucial role in this regards. From conservation perspective polyandry played crucial role to manage local resources and in population dynamics in the past. This paper is based on field survey carried out in two different time periods (1998 and 2008 in order to compare or understand changing pattern of polyandry. In last couple of years, polyandry system has changed very rapidly in Loba communities of Upper Mustang. Rising community awareness, multiple economic opportunities, improve communication, foreign employment, modern education, open tourism, road access and other visual and in visual forces has lead society from close to open and more wider side or increase the horizon of young generation. Polyandry system is directly affected. DOI: http://dx.doi.org/10.3126/dsaj.v6i0.8480 Dhaulagiri Journal of Sociology and Anthropology Vol. 6, 2012 75-106

  17. Study of the changes in the magnetic properties of stainless steels under mechanical treatment

    Energy Technology Data Exchange (ETDEWEB)

    Iankov, R.; Rusanov, V., E-mail: rusanov@phys.uni-sofia.bg [Magna Powertrain Ltd., Industrial Zone Rakowski (Bulgaria); Paneva, D.; Mitov, I. [Institute of Catalysis, Bulgarian Academy of Sciences (Bulgaria); Trautwein, A. X. [Institut für Physik, Universität zu Lübeck (Germany)

    2016-12-15

    Six types of stainless steels (SS) were studied for changes in its structure and magnetic properties under mechanical treatment. Depending on intensity and duration of the process of plastic deformation and the SS type the paramagnetic austenite structure transforms partially to completely into ferrite structure with ferromagnetic behaviour. Some of the SS tested were found slightly modified yet in the process of its manufacturing. Only one SS type with high Ni content preserved its structure and paramagnetic properties even after very intense mechanical treatment.

  18. Superposed epoch analysis of pressure and magnetic field configuration changes in the plasma sheet

    International Nuclear Information System (INIS)

    Kistler, L.M.; Moebius, E.; Baumjohann, W.; Nagai, T.

    1993-01-01

    The authors report on an analysis of pressure and magnetic configuration within the plasma sheet following the initiation of substorm events. They have constructed this time dependent picture by using an epoch analysis of data from the AMPTE/IRM spacecraft. This analysis procedure can be used to construct a unified picture of events, provided they are reproducible, from a statistical analysis of a series of point measurements. The authors first determine the time dependent pressure changes in the plasma sheet. With some simplifying assumptions they then determine the z dependence of the pressure profiles, and from this distribution determine how field lines in the plasma sheet map to the neutral sheet

  19. Structural and magnetic properties of rapidly quenched and as-cast bulk NdFeBCu alloys

    International Nuclear Information System (INIS)

    Sanchez Ll, J.L.; Bustamante S, R.; Barthem, V.M.T.S.; Miranda, P.E.V. de

    2005-01-01

    A study of the structural and magnetic properties of as-cast and melt spun (x)Nd 2 Fe 14 B(100-x)Nd 70 Cu 30 alloys (x=10, 50 and 75%wt.) is presented. In as-cast alloys for x=10wt%. the formation of a high coercivity phase, referred to as N (T C =240 deg. C, i H C =4.9kOe) is found. N is a (Nd-Fe)-based phase with a Fe/Nd ratio lower than that of phase Nd 2 Fe 14 B (φ). It is suggested that this phase is related to the A 1 phase found in binary Nd-Fe alloys. In melt-spun alloys, at the same x value of 10wt%, another hard phase is found which is suggested to be the Nd 6 Fe 13 Cu δ-phase (T C =192 deg. C, i H C =4.8kOe). Transmission electron microscope (TEM) micrographs of the ribbons with x=10wt% shows the formation of nanograins with a non-uniform grain size distribution. In cast alloys with x=50 and 75wt% large slab-like grains of φ are formed, in the inter-granular region a Nd-Cu eutectic phase and Nd grains, are observed. High coercivities are obtained in ribbons with x=50wt% ( i H C =19.7kOe) and 75wt% ( i H C =13.0kOe). A slight reduction in the Curie temperature of the φ-phase with respect to the bulk value is found in these ribbons

  20. Evaluation of a new T2 Magnetic Resonance assay for rapid detection of emergent fungal pathogen Candida auris on clinical skin swab samples.

    Science.gov (United States)

    Sexton, D Joseph; Bentz, Meghan L; Welsh, Rory M; Litvintseva, Anastasia P

    2018-06-25

    Candida auris is a multidrug-resistant pathogenic yeast whose recent emergence is of increasing public-health concern. C. auris can colonize multiple body sites, including patients' skin, and survive for weeks in the healthcare environment, facilitating patient-to-patient transmission and fueling healthcare-associated outbreaks. Rapid and accurate detection of C. auris colonization is essential for timely implementation of infection control measures and prevent transmission. Currently, axilla/groin composite swabs, used to assess colonization status, are processed using a culture-based method that is sensitive and specific but requires 14 days. This delay limits the opportunity to respond and highlights the need for a faster alternative. The culture-independent T2 Magnetic Resonance (T2MR) system is a rapid diagnostic platform shown to detect target pathogens of interest from unprocessed blood samples in T2 assay was evaluated for screening of the skin surveillance samples. Inclusivity and limit of detection of the T2 C. auris assay were assessed with spiked samples in a representative skin flora background. The T2 C. auris assay recognized isolates from each of the 4 known clades of C. auris and consistently detected cells at 5 CFU/mL. Finally, 89 clinical axilla/groin swab samples were processed with the T2 C. auris assay. The culture-based diagnostic assay was used as a gold standard to determine performance statistics including sensitivity (0.89) and specificity (0.98). Overall, the T2 C. auris assay performed well as a rapid diagnostic and could help expedite the detection of C. auris in patient skin swabs. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  1. Microstructure and magnetic behavior of Mn doped GeTe chalcogenide semiconductors based phase change materials

    Science.gov (United States)

    Adam, Adam Abdalla Elbashir; Cheng, Xiaomin; Abuelhassan, Hassan H.; Miao, Xiang Shui

    2017-06-01

    Phase-change materials (PCMs) are the most promising candidates to be used as an active media in the universal data storage and spintronic devices, due to their large differences in physical properties of the amorphous-crystalline phase transition behavior. In the present study, the microstructure, magnetic and electrical behaviors of Ge0.94Mn0.06Te thin film were investigated. The crystallographic structure of Ge0.94Mn0.06Te thin film was studied sing X-ray diffractometer (XRD) and High Resolution Transmission Electron Microscope (HR-TEM). The XRD pattern showed that the crystallization structure of the film was rhombohedral phase for GeTe with a preference (202) orientation. The HR-TEM image of the crystalline Ge0.94Mn0.06Te thin film demonstrated that, there were two large crystallites and small amorphous areas. The magnetization as a function of the magnetic field analyses of both amorphous and crystalline states showed the ferromagnetic hysteretic behaviors. Then, the hole carriers concentration of the film was measured and it found to be greater than 1021 cm-3 at room temperature. Moreover, the anomalous of Hall Effect (AHE) was clearly observed for the measuring temperatures 5, 10 and 50 K. The results demonstrated that the magnitude of AHE decreased when the temperature was increasing.

  2. MAGNET

    CERN Multimedia

    Benoit Curé

    2010-01-01

    The magnet worked very well at 3.8 T as expected, despite a technical issue that manifested twice in the cryogenics since June. All the other magnet sub-systems worked without flaw. The issue in the cryogenics was with the cold box: it could be observed that the cold box was getting progressively blocked, due to some residual humidity and air accumulating in the first thermal exchanger and in the adsorber at 65 K. This was later confirmed by the analysis during the regeneration phases. An increase in the temperature difference between the helium inlet and outlet across the heat exchanger and a pressure drop increase on the filter of the adsorber were observed. The consequence was a reduction of the helium flow, first compensated by the automatic opening of the regulation valves. But once they were fully opened, the flow and refrigeration power reduced as a consequence. In such a situation, the liquid helium level in the helium Dewar decreased, eventually causing a ramp down of the magnet current and a field...

  3. MAGNET

    CERN Multimedia

    Benoit Curé.

    The magnet operation restarted end of June this year. Quick routine checks of the magnet sub-systems were performed at low current before starting the ramps up to higher field. It appeared clearly that the end of the field ramp down to zero was too long to be compatible with the detector commissioning and operations plans. It was decided to perform an upgrade to keep the ramp down from 3.8T to zero within 4 hours. On July 10th, when a field of 1.5T was reached, small movements were observed in the forward region support table and it was decided to fix this problem before going to higher field. At the end of July the ramps could be resumed. On July 28th, the field was at 3.8T and the summer CRAFT exercise could start. This run in August went smoothly until a general CERN wide power cut took place on August 3rd, due to an insulation fault on the high voltage network outside point 5. It affected the magnet powering electrical circuit, as it caused the opening of the main circuit breakers, resulting in a fast du...

  4. MAGNET

    CERN Multimedia

    B. Curé

    2013-01-01

    The magnet is fully stopped and at room temperature. The maintenance works and consolidation activities on the magnet sub-systems are progressing. To consolidate the cryogenic installation, two redundant helium compressors will be installed as ‘hot spares’, to avoid the risk of a magnet downtime in case of a major failure of a compressor unit during operation. The screw compressors, their motors, the mechanical couplings and the concrete blocks are already available and stored at P5. The metallic structure used to access the existing compressors in SH5 will be modified to allow the installation of the two redundant ones. The plan is to finish the installation and commissioning of the hot spare compressors before the summer 2014. In the meantime, a bypass on the high-pressure helium piping will be installed for the connection of a helium drier unit later during the Long Shutdown 1, keeping this installation out of the schedule critical path. A proposal is now being prepared for the con...

  5. Selective deletion of cochlear hair cells causes rapid age-dependent changes in spiral ganglion and cochlear nucleus neurons.

    Science.gov (United States)

    Tong, Ling; Strong, Melissa K; Kaur, Tejbeer; Juiz, Jose M; Oesterle, Elizabeth C; Hume, Clifford; Warchol, Mark E; Palmiter, Richard D; Rubel, Edwin W

    2015-05-20

    During nervous system development, critical periods are usually defined as early periods during which manipulations dramatically change neuronal structure or function, whereas the same manipulations in mature animals have little or no effect on the same property. Neurons in the ventral cochlear nucleus (CN) are dependent on excitatory afferent input for survival during a critical period of development. Cochlear removal in young mammals and birds results in rapid death of target neurons in the CN. Cochlear removal in older animals results in little or no neuron death. However, the extent to which hair-cell-specific afferent activity prevents neuronal death in the neonatal brain is unknown. We further explore this phenomenon using a new mouse model that allows temporal control of cochlear hair cell deletion. Hair cells express the human diphtheria toxin (DT) receptor behind the Pou4f3 promoter. Injections of DT resulted in nearly complete loss of organ of Corti hair cells within 1 week of injection regardless of the age of injection. Injection of DT did not influence surrounding supporting cells directly in the sensory epithelium or spiral ganglion neurons (SGNs). Loss of hair cells in neonates resulted in rapid and profound neuronal loss in the ventral CN, but not when hair cells were eliminated at a more mature age. In addition, normal survival of SGNs was dependent on hair cell integrity early in development and less so in mature animals. This defines a previously undocumented critical period for SGN survival. Copyright © 2015 the authors 0270-6474/15/357878-14$15.00/0.

  6. Carcinomas of endometrium and cervix: magnetic resonance assessment of changes following radiotherapy

    International Nuclear Information System (INIS)

    Olega, L.; Cura, J.L. del; Grande, D.; Martinez, B.; Fernandez, A.; Martinez, S.; Martin, J.C.

    1998-01-01

    To present the changes induced at the tissue level in patients subjected to external radiotherapy and brachytherapy to treat carcinomas of endometrium and cervix, as disclosed by magnetic resonance (MR). The MR study dealt with 26 patients 14 with endometrial carcinoma and 12 with cervical carcinoma who were treated with external radiotherapy and brachytherapy. The features assessed retrospectively were bone marrow of the lumbar and sacral spine, pelvic fat, abdominal wall, uterine, junction and size, rectal and bladder wall and pelvic musculature. The most common changes observed after radiotherapy according to our study were changes in signal intensity in the bone marrow of the pelvic bones (88%), followed by changes in the pelvic fat (65.3%). Other radiotherapy-related findings in order of frequency were cervical fibrosis, colitis and cystitis. Radiotherapy induces changes in the tissue of the pelvic structures, and the knowledge of these changes is important in the evaluation of the follow-up studies of these patients. (Author) 12 refs

  7. Loss of Magnet® Designation and Changes in RN Work Engagement: A Report on How 1 Hospital's Culture Changed Over Time.

    Science.gov (United States)

    Wonder, Amy Hagedorn; York, Jacki; Jackson, Kathryn L; Sluys, Teresa D

    2017-10-01

    The aim of this study was to examine the loss of Magnet® designation and how RNs' work engagement changed at 1 community hospital. The importance of RN work engagement to promote quality and safety is widely recognized in healthcare. Ongoing consistent research is critical to determine what organizational structures are needed to support RN work engagement. This was a comparative, descriptive, correlational study of RN cohorts at 2 time points: time 1 (T1), in 2011 during Magnet designation (n = 119), and time 2 (T2), in 2016, approximately 2 years after the loss of Magnet designation (n = 140). The cohort of RNs at T2 reported significantly lower work engagement in the time period after the loss of Magnet designation when compared with the RN cohort at T1 during Magnet designation (P ≤ .0002). These results provide insights for clinical leaders striving to support a culture of RN work engagement and quality care.

  8. Evaluation of sclerosis in Modic changes of the spine using susceptibility-weighted magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Böker, Sarah M., E-mail: Sarah-maria.boeker@charite.de [Department of Radiology, Charité, Charitéplatz 1, 10117 Berlin (Germany); Bender, Yvonne Y., E-mail: Yi-na.bender@charite.de [Department of Radiology, Charité, Charitéplatz 1, 10117 Berlin (Germany); Adams, Lisa C., E-mail: Lisa.adams@charite.de [Department of Radiology, Charité, Charitéplatz 1, 10117 Berlin (Germany); Fallenberg, Eva M., E-mail: Eva.fallenberg@charite.de [Department of Radiology, Charité, Augustenburger Platz 1, 13353 Berlin (Germany); Wagner, Moritz, E-mail: Moritz.wagner@charite.de [Department of Radiology, Charité, Charitéplatz 1, 10117 Berlin (Germany); Hamm, Bernd, E-mail: Bernd.hamm@charite.de [Department of Radiology, Charité, Charitéplatz 1, 10117 Berlin (Germany); Makowski, Marcus R., E-mail: Marcus.makowski@charite.de [Department of Radiology, Charité, Charitéplatz 1, 10117 Berlin (Germany)

    2017-03-15

    Highlights: • SWMR allows a reliable detection of sclerosis in Modic changes. • SWI has a better accuracy for detection of sclerosis in Modic changes than T1/T2w MR. • By applying SWMR the use of additional CT/radiography can be minimized. - Abstract: Purpose: To evaluate the diagnostic performance of susceptibility-weighted magnetic resonance imaging (SWMR) for the differentiation of sclerotic and non-sclerotic Modic changes (MC) of the spine compared to computed tomography (CT) and radiographs. Materials and methods: The Institutional Ethics-Review-Board approved this prospective study in advance. Written consent was obtained from all subjects. SWMR and standard T1/T2 MR of the cervical (n = 21) and/or lumbar spine (n = 34) were performed in 54 patients. 21 patients served as control. 18 patients were evaluated with CT; in all other patients radiographs were available. 67 Modic changes were identified on T1/T2 MR. On SWMR changes were classified as sclerotic and non-sclerotic based on signal intensity measurements. The sensitivity and specificity of SWMR and T1/T2 MR for differentiating between sclerotic and non-sclerotic Modic changes were determined with CT and radiographs as reference standard. Results: On SWMR, signal measurements between sclerotic and non-sclerotic Modic changes differed significantly (p < 0.01). On T1- and T2-weighted MR no significant difference (p > 0.05) was measured. On SWMR, a reliable differentiation between sclerotic and non-sclerotic Modic changes could be achieved, with a sensitivity of 100% and specificity of 95%. In contrast, the combination of T1-/T2-weighted MR yielded a significantly lower sensitivity to detect sclerosis (20%). Conclusion: SWMR allows a reliable detection of sclerosis in Modic changes with a higher accuracy compared to standard spine MR sequences, using radiographs and CT as reference standard.

  9. Changes in the electrocardiograms of rats and dogs exposed to dc magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Gaffey, C.T.; Tenforde, T.S.

    1979-03-01

    An evaluation of cardiovascular performance in magnetic fields (MF) is being undertaken. Cardiovascular performance is evaluated as a function of the MF strength. Since the vector characteristics of MF may be a factor influencing cardiovascular function, the positional arrangement of animals in a MF is being tested. In practice, each test animal is inserted between the poles of a magnet in a selected orientation that locates the heart in the center of the MF. The electrocardogram (ECG) is recorded before, during, and following the application of a MF. The interval between summits of the R waves allows the average heart rate to be obtained. The average respiratory rate is measured from the baseline shifts in the ECG trace. The major change in the ECG pattern induced by a MF is an increase in the amplitude of the T wave of rats and dogs. In our rat study a 20,000 gauss field increased the T wave by about 450%; the dog's T wave was increased 750% by a 16,000 gauss field. These biomagnetic effects appear to be reversible. Out experiments with rats and dogs were designed to test for the presence of a magnetic strength threshold (MST) to evoke T wave enhancement. The MST is defined as the minimum number of gauss to product a measurable change with T wave amplitude. The MTS is 3.0 kgauss for rats and 0.9 kgauss for dogs. Augmentation of the T wave was found to be greatest when thelines of the MF were perpendicular to the long axis of the body and least when parallel. Hence, the orientation of the subject in the MF influences the ECG profile.

  10. Investigation of Factors Affecting Body Temperature Changes During Routine Clinical Head Magnetic Resonance Imaging

    Science.gov (United States)

    Kim, Myeong Seong

    2016-01-01

    Background Pulsed radiofrequency (RF) magnetic fields, required to produce magnetic resonance imaging (MRI) signals from tissue during the MRI procedure have been shown to heat tissues. Objectives To investigate the relationship between body temperature rise and the RF power deposited during routine clinical MRI procedures, and to determine the correlation between this effect and the body’s physiological response. Patients and Methods We investigated 69 patients from the Korean national cancer center to identify the main factors that contribute to an increase in body temperature (external factors and the body’s response) during a clinical brain MRI. A routine protocol sequence of MRI scans (1.5 T and 3.0 T) was performed. The patient’s tympanic temperature was recorded before and immediately after the MRI procedure and compared with changes in variables related to the body’s physiological response to heat. Results Our investigation of the physiological response to RF heating indicated a link between increasing age and body temperature. A higher increase in body temperature was observed in older patients after a 3.0-T MRI (r = 0.07, P = 0.29 for 1.5-T MRI; r = 0.45, P = 0.002 for 3.0-T MRI). The relationship between age and body heat was related to the heart rate (HR) and changes in HR during the MRI procedure; a higher RF power combined with a reduction in HR resulted in an increase in body temperature. Conclusion A higher magnetic field strength and a decrease in the HR resulted in an increase in body temperature during the MRI procedure. PMID:27895872

  11. Novel Magnetic-to-Thermal Conversion and Thermal Energy Management Composite Phase Change Material

    Directory of Open Access Journals (Sweden)

    Xiaoqiao Fan

    2018-05-01

    Full Text Available Superparamagnetic materials have elicited increasing interest due to their high-efficiency magnetothermal conversion. However, it is difficult to effectively manage the magnetothermal energy due to the continuous magnetothermal effect at present. In this study, we designed and synthesized a novel Fe3O4/PEG/SiO2 composite phase change material (PCM that can simultaneously realize magnetic-to-thermal conversion and thermal energy management because of outstanding thermal energy storage ability of PCM. The composite was fabricated by in situ doping of superparamagnetic Fe3O4 nanoclusters through a simple sol–gel method. The synthesized Fe3O4/PEG/SiO2 PCM exhibited good thermal stability, high phase change enthalpy, and excellent shape-stabilized property. This study provides an additional promising route for application of the magnetothermal effect.

  12. Change of cobalt magnetic anisotropy and spin polarization with alkanethiolates self-assembled monolayers

    International Nuclear Information System (INIS)

    Campiglio, Paolo; Breitwieser, Romain; Repain, Vincent; Guitteny, Solène; Chacon, Cyril; Bellec, Amandine; Lagoute, Jérôme; Girard, Yann; Rousset, Sylvie; Sassella, Adele; Imam, Mighfar; Narasimhan, Shobhana

    2015-01-01

    We demonstrate that the deposition of a self-assembled monolayer of alkanethiolates on a 1 nm thick cobalt ultrathin film grown on Au(111) induces a spin reorientation transition from in-plane to out-of-plane magnetization. Using ab initio calculations, we show that a methanethiolate layer changes slightly both the magnetocrystalline and shape anisotropy, both effects almost cancelling each other out for a 1 nm Co film. Finally, the change in hysteresis cycles upon alkanethiolate adsorption could be assigned to a molecular-induced roughening of the Co layer, as shown by STM. In addition, we calculate how a methanethiolate layer modifies the spin density of states of the Co layer and we show that the spin polarization at the Fermi level through the organic layer is reversed as compared to the uncovered Co. These results give new theoretical and experimental insights for the use of thiol-based self-assembled monolayers in spintronic devices. (paper)

  13. Positional and morphologic changes of the temporomandibular joint disc using magnetic resonance imaging

    International Nuclear Information System (INIS)

    Ahn, Hyoun Suk; Cho, Su Beom; Koh, Kwang Joon

    2001-01-01

    To evaluate displacement and morphologic changes of the temporomandibular joint (TMJ) disc in patient with internal derangement using magnetic resonance imaging (MRI). One hundred and forty five MR images of TMJs in 73 patients were evaluated. Positional and morphologic changes of the TMJ disc were assessed. Lateral or medial disc displacement was also evaluated on cornal images. Among 63 discs with anterior disc displacement, 37 discs were assessed as a biconcave disc and 21 as a deformed disc. Rotational disc displacement was observed in 35 disc. Anteromedial disc displacement was observed in 29 discs, and anterolateral direction in 6 discs. Among 35 rotational displacement, 5 biconcave discs and 21 deformed discs were observed. Rotational and sideways displacement of TMJ discs were found to be common and an important aspect of internal derangement. This study also suggests that sagittal and coronal images of the TMJ have complementary abilities for an assessment of joint abnormality

  14. Hemodynamic Change in Pulmonary Vein Stenosis after Radiofrequency Ablation: Assessment with Magnetic Resonance Angiography

    Energy Technology Data Exchange (ETDEWEB)

    Yun, Doyoung; Jung, Jung Im; Oh, Yong Seog; Youn, Ho Joong [Seoul St. Mary' s Hospital, College of Medicine, The Catholic University of Korea, Seoul (Korea, Republic of)

    2012-11-15

    We present a case of pulmonary vein (PV) stenosis after radio-frequency (RF) ablation, in which a hemodynamic change in the pulmonary artery was similar to that of congenital PV atresia on time-resolved contrast-enhanced magnetic resonance angiography (TR-MRA). A 48-year-old man underwent RF ablation due to atrial fibrillation. The patient subsequently complained of hemoptysis, dyspnea on exertion, and right chest pain. Right PV stenosis after catheter ablation was diagnosed through chest computed tomography and lung perfusion scan. Pulmonary TR-MRA revealed the pulmonary artery via systemic arterial collaterals and draining systemic collateral veins. On a velocity-encoded cine image, the flow direction of the right pulmonary artery was reversed in the diastolic phase and the left pulmonary artery demonstrated continuous forward flow throughout the cardiac cycle. These hemodynamic changes were similar to those seen in congenital unilateral PV atresia.

  15. A statistical study of magnetic field magnitude changes during substorms in the near earth tail

    Science.gov (United States)

    Lopez, R. E.; Lui, A. T. Y.; Mcentire, R. W.; Potemra, T. A.; Krimigis, S. M.

    1990-01-01

    Using AMPTE/CCE data taken in 1985 and 1986 when the CCE apogee (8.8 earth radii) was within 4.5 hours of midnight, 167 injection events in the near-earth magnetotail have been cataloged. These events are exactly or nearly dispersionless on a 72-sec time scale from 25 keV to 285 keV. The changes in the field magnitude are found to be consistent with the expected effects of the diversion/disruption of the cross-tail current during a substorm, and the latitudinal position of the current sheet is highly variable within the orbit of CCE. The local time variation of the magnetic-field changes implies that the substorm current wedge is composed of longitudinally broad Birkeland currents.

  16. The observation of resistivity change on the ultrasonic treated Fe-Cr ODS sinter alloy under magnetic field influence

    Science.gov (United States)

    Silalahi, Marzuki; Purwanto, Setyo; Mujamilah; Dimyati, Arbi

    2018-03-01

    About the observation of resistivity change on the ultrasonic treated Fe-Cr ODS sinter alloy under magnetic field influence. This paper reported about the observation of the resistivity change in the ultrasonic pre-treated Fe-Cr ODS sinter alloy under the influence of magnetic field at the Center for Science and Technology of Advanced Material, Nuclear Energy Agency of Indonesia. Fe-Cr ODS alloy were sinthesized by vacuum sintering of Fe- and Cr-powder dispersed Y2O3. However, before sintering the powder mixture was subjected to the irradiation process by ultrasonic for 50 hours at 20 kHz and then isostatic pressed up to 50.91 MPa to form a coin of 10 mm in diameter. LCR meassurement revealed the decreasing of resistivity about 3 times by increasing of applied magnetic field from 0 to 70 mT. In addition, VSM meassurement was performed on both as powder material and as sintered sample. The results showed increasing the magnetization with increasing magnetic field and the curve exhibits almost exact symmetry S-form with small hysterese indicating fast changing magnetization and demagnetization capability without energy loss. This opens strong speculations about the existence of magnetoresistant property of the material which is important for many application in field of sensors or electro magnetic valves.

  17. Electron-irradiation induced changes in structural and magnetic properties of Fe and Co based metallic glasses

    Energy Technology Data Exchange (ETDEWEB)

    Kane, S.N., E-mail: kane_sn@yahoo.com [School of Physics, D.A. University, Khandwa Road Campus, Indore 452001 (India); Satalkar, M., E-mail: satalkar.manvi@gmail.com [School of Physics, D.A. University, Khandwa Road Campus, Indore 452001 (India); Ghosh, A.; Shah, M. [School of Physics, D.A. University, Khandwa Road Campus, Indore 452001 (India); Ghodke, N. [UGC-DAE CSR, University Campus, Khandwa Road, Indore 452001 (India); Pramod, R.; Sinha, A.K.; Singh, M.N.; Dwivedi, J. [Raja Ramanna Centre for Advanced Technology, P.O. CAT, Indore 452013 (India); Coisson, M.; Celegato, F.; Vinai, F.; Tiberto, P. [INRIM, Electromagnetism Division, Strada Delle Cacce 91, I-10135 TO (Italy); Varga, L.K. [RISSPO, Hungarian Academy of Sciences, P.O. Box 49, 1525 Budapest (Hungary)

    2014-12-05

    Highlights: • Enhancement of Ms by low electron irradiation dose in Fe-based alloy. • Variation of magnetic properties by electron irradiation induced ordered phase. • Electron irradiation alters TM-TM distance and, magnetic properties. - Abstract: Electron-irradiation induced changes in structural and, magnetic properties of Co{sub 57.6}Fe{sub 14.4}Si{sub 4.8}B{sub 19.2}Nb{sub 4}, Fe{sub 72}Si{sub 4.8}B{sub 19.2}Nb{sub 4} and, Co{sub 72}Si{sub 4.8}B{sub 19.2}Nb{sub 4} metallic glasses were studied using magnetic hysteresis and, synchrotron X-ray diffraction measurements. Results reveal composition dependent changes of magnetic properties in electron irradiated metallic glasses. A low electron irradiation dose (15 kGy) enhances saturation magnetization (up to 62%) in Fe-based alloy (Fe{sub 72}Si{sub 4.8}B{sub 19.2}Nb{sub 4}). Synchrotron XRD measurements reveal that electron irradiation transforms the amorphous matrix to a more ordered phase, accountable for changes in magnetic properties.

  18. Acute rCBF changes in depressed patients receiving repetitive transcranial magnetic stimulation (rTMS)

    International Nuclear Information System (INIS)

    Haindl, W.; Loo, C.; Mitchell, P.; Sachdev, P.; Zheng, X.; Som, S.; Walker, B.

    1999-01-01

    Full text: Electroconvulsant therapy (ECT) is very effective in treatment resistant severe depression with response rates of 70-90%. However, ECT has major limitations including the need for anaesthesia, memory difficulties and public apprehension about its use. Transcranial magnetic stimulation (rTMS) has been used as a diagnostic technique in neurology with recent reports of potential benefit in depressed patients. In this study, 5 patients (3 females, 2 males aged 36-66 years, mean 48.6 years) with major depression underwent SPET brain scanning using a Picker 3000 triple-headed camera. Each patient had a baseline rCBF scan with 500 MBq of 99 Tc m HMPAO injected intravenously during sham rTMS. On the following day, each patient received another 500 MBq of 99 Tc m HMPAo during rTMS to the left dorsolateral prefrontal cortex using a Magstim Super Rapid magnetic stimulator with a 70-mm figure eight coil. The stimulator parameters were 15 Hz, 90% of resting motor threshold, 1 s on 3 s off for 30 trains prior to injection and 15-30 trains following injection. Each patient continued to receive their usual medication during this period. The reconstructed SPET data sets were normalized to the global mean, registered to the Talairach template and analysed using statistical parametric mapping (SPM). Compared with the baseline group, the rTMS group showed a significant perfusion increase in the pre-frontal cortices, especially on the left, and also in the anterior left temporal lobe (P < 0.05). Frontal lobe perfusion reduction is a common finding in depression. This study demonstrates the ability of rTMS to acutely increase frontal lobe perfusion, and therefore a possible mechanism for its therapeutic use as an adjunct to pharmacological therapy or as an alternative to ECT in depression

  19. Increased Sensitivity to Pathological Brain Changes Using Co-registration of Magnetic Resonance Imaging Scans

    Energy Technology Data Exchange (ETDEWEB)

    Burdett, J.; Stevens, J.; Flugel, D.; Williams, E.; Duncan, J.S.; Lemieux, L. [National Society for Epilepsy, Chalfont St Peter (United Kingdom). The MRI Unit

    2006-12-15

    Purpose: To compare automatic software-based co-registration of serial magnetic resonance imaging (MRI) scans with conventional visual comparison, by expert neuroradiologists.Material and Methods: Sixty-four patients who were referred to our epilepsy MRI unit for cerebral imaging were identified as having potentially, non- or slow-growing lesions or cerebral atrophy and followed with sequential scans over a period of up to 8 years, resulting in a total of 92 pairs of scans. Scans were categorized as showing either lesions or atrophy. Each pair of scans was reviewed twice for the presence of change, with and without co-registration, performed using automated software. Results: Co-registration and visual reporting without co-registration were discordant in the lesions group in nine out of 69 datasets (13%), and in 16 out of 23 pairs of scans in the atrophy group (69%). The most common cause of discordance was visual reporting not detecting changes apparent by co-registration. In three cases, changes detected visually were not detected following co-registration. Conclusion: In the group of patients studied, co-registration was more sensitive for detecting changes than visual comparison, particularly with respect to atrophic changes of the brain. With the increasing availability of sophisticated independent consoles attached to MRI scanners that may be used for image co-registration, we propose that serial T1-weighted volumetric MRI brain co-registration should be considered for integration into routine clinical practice to assess patients with suspected progressive disease.

  20. Increased Sensitivity to Pathological Brain Changes Using Co-registration of Magnetic Resonance Imaging Scans

    International Nuclear Information System (INIS)

    Burdett, J.; Stevens, J.; Flugel, D.; Williams, E.; Duncan, J.S.; Lemieux, L.

    2006-01-01

    Purpose: To compare automatic software-based co-registration of serial magnetic resonance imaging (MRI) scans with conventional visual comparison, by expert neuroradiologists.Material and Methods: Sixty-four patients who were referred to our epilepsy MRI unit for cerebral imaging were identified as having potentially, non- or slow-growing lesions or cerebral atrophy and followed with sequential scans over a period of up to 8 years, resulting in a total of 92 pairs of scans. Scans were categorized as showing either lesions or atrophy. Each pair of scans was reviewed twice for the presence of change, with and without co-registration, performed using automated software. Results: Co-registration and visual reporting without co-registration were discordant in the lesions group in nine out of 69 datasets (13%), and in 16 out of 23 pairs of scans in the atrophy group (69%). The most common cause of discordance was visual reporting not detecting changes apparent by co-registration. In three cases, changes detected visually were not detected following co-registration. Conclusion: In the group of patients studied, co-registration was more sensitive for detecting changes than visual comparison, particularly with respect to atrophic changes of the brain. With the increasing availability of sophisticated independent consoles attached to MRI scanners that may be used for image co-registration, we propose that serial T1-weighted volumetric MRI brain co-registration should be considered for integration into routine clinical practice to assess patients with suspected progressive disease