1,643 research outputs found
NMR relaxation time around a vortex in stripe superconductors
Site-dependent NMR relaxation time is calculated in the vortex
state using the Bogoliubov-de Gennes theory, taking account of possible
"field-induced stripe'' states in which the magnetism arises locally around a
vortex core in d-wave superconductivity. The recently observed huge enhancement
below at a core site in TlBaCuO is
explained. The field-induced stripe picture explains consistently other
relevant STM and neutron experiments.Comment: 4 pages, 4 figure
Finding feasible action towards urban transformations
While innovative approaches to urban transformations are increasingly proposed, scholars often overlook challenges faced by endogenous actors (e.g. urban planners) tasked with taking action within non-ideal, real-world settings. Here we argue that an âinsideâ view of transformations (focused on judgment in practice) is needed to complement existing âoutsideâ views (focused on assessment), where the feasibility of action becomes a central concern. This recasts urban transformations in a discretised perspective. It suggests a view of transformation pathways as both directed and stochastic, and emergent from an unfolding series of âfuzzy action momentsâ. Principles for bridging urban science and planning are derived.Peer reviewe
GINZBURG-LANDAU THEORY OF VORTICES IN -WAVE SUPERCONDUCTORS
Ginzburg-Landau theory is used to study the properties of single vortices and
of the Abrikosov vortex lattice in a superconductor. For a single
vortex, the -wave order parameter has the expected four-lobe structure in a
ring around the core and falls off like at large distances. The
topological structure of the -wave order parameter consists of one
counter-rotating unit vortex, centered at the core, surrounded by four
symmetrically placed positive unit vortices. The Abrikosov lattice is shown to
have a triangular structure close to and an oblique structure at lower
temperatures. Comparison is made to recent neutron scattering data.Comment: 4 pages, REVTeX, 3 figures available upon reques
Suomen maataloushistorian pÀÀlinjat
Suomen maatalouden historia on ollut viljelijÀn kamppailua toimeentulonsa puolesta vaihtelevissa olosuhteissa. Maatilatalouden rakennemuutokset ja viljelymenetelmien vaihtaminen ovat olleet tÀrkeitÀ keinoja maanviljelijÀn koettaessa mukautua alati liikkeellÀ olevaan taloudelliseen kehitykseen. PerinnÀisen maatalouden kaudella esihistoriallisen ajan lopulta 1800-luvulle tekninen kehitys oli varsin hidasta, mutta nopeampaa kehitystÀ tapahtui taloudellisen toiminnan alalla maatilatalouden painopisteen siirtyessÀ jatkuvasti sektorilta toiselle tai rinnakkaisesta viljelymenetelmÀstÀ toiseen. KÀsitys maatalouskehityksemme staattisesta luonteesta perinnÀisen maatalouden kaudella, joka perustuu yksipuolisesti teknisen kehityksen hitauteen, osoittautuu nÀin ollen harhakuvaksi. Viimeisen sadan vuoden aikana maatalouskehityksen luonne on suuresti muuttunut. Kehitykselle on ollut luonteenomaista nopeasti edistyvÀ maataloustekniikka ja siirtyminen omavaraistaloudesta vaihdantatalouteen. Seurauksena on ollut sopeutumisvaikeuksia sekÀ maatalouden tuotantoyksiköille, maatiloille, ettÀ maatalousvÀestölle. Huomattavalta osalta nÀistÀ sopeutumisvaikeuksista johtuu, ettÀ maatalouden taloudellisen ja sosiaalisen kehityksen vÀlillÀ on ollut kitkaa ja maatalouden tuottavuuden kasvu on jÀÀnyt jÀlkeen yleisestÀ taloudellisesta kasvusta
- and -wave components induced around a vortex in -wave superconductors
Vortex structure of -wave superconductors is microscopically
analyzed in the framework of the quasi-classical Eilenberger equations. If the
pairing interaction contains an -wave (-wave) component in addition
to a -wave component, the -wave (-wave) component of
the order parameter is necessarily induced around a vortex in
-wave superconductors. The spatial distribution of the induced
-wave and -wave components is calculated. The -wave component has
opposite winding number around vortex near the -vortex core and
its amplitude has the shape of a four-lobe clover. The amplitude of
-component has the shape of an octofoil. These are consistent with
results based on the GL theory.Comment: RevTex,9 pages, 6 figures in a uuencoded fil
Field induced state and marginal stability of high-Tc superconductors
It is shown that the {\em complex} component is generated in d-wave
superconductor in the magnetic field. As one enters superconducting state at
finite field the normal to superconducting transition occurs into bulk
state . The driving force for the transition is the
linear coupling between magnetic field and non zero magnetization of the
condensate. The external magnetic field violates parity
and time reversal symmetries and the nodal quasiparticle states respond by
generating the component of the order parameter, with the magnitude
estimated to be on the order of few Kelvin. Parity (P) and time reversal (T)
symmetries are violated in this state.Comment: 4 pages, latex file with two eps figure file
Antibody responses to nasopharyngeal carriage of Streptococcus pneumoniae in adults: A longitudinal household study
Background. Natural immunity to Streptococcus pneumoniae is thought to be induced by exposure to S. pneumoniae or cross-reactive antigens. No longitudinal studies of carriage of and immune responses to S. pneumoniae have been conducted using sophisticated immunological laboratory techniques.Methods. We enrolled 121 families with young children into this study. Nasopharyngeal (NP) swabs were collected monthly for 10 months from all family members and were cultured in a standard fashion. Cultured S. pneumoniae isolates were serotyped. At the beginning (month 0) and end (month 10) of the study, venous blood was collected from family members 118 years old. Serotype-specific antipolysaccharide immunoglobulin G (IgG) and functional antibody and antibodies to pneumolysin, pneumococcal surface protein A (PspA), and pneumococcal surface antigen A (PsaA) were measured in paired serum samples.Results. Levels of anticapsular IgG increased significantly after carriage of serotypes 9V, 14, 18C, 19F, and 23F by an individual or family member. For serotype 14, a higher level of anticapsular IgG at the beginning of the study was associated with reduced odds of carriage (P = .0006). There was a small (similar to 20%) but significant increase in titers of antibodies to PsaA and pneumolysin but no change in titers of antibody to PspA.Conclusions. Adults respond to NP carriage by mounting anticapsular and weak antiprotein antibody responses, and naturally induced anticapsular IgG can prevent carriage
A semi-automatic workflow to process images from small mammal camera traps
Camera traps have become popular for monitoring biodiversity, but the huge amounts of image data that arise from camera trap monitoring represent a challenge and artificial intelligence is increasingly used to automatically classify large image data sets. However, it is still challenging to combine automatic classification with other steps and tools needed for efficient, quality-assured and adaptive processing of camera trap images in long-term monitoring programs. Here we propose a semi-automatic workflow to process images from small mammal cameras that combines all necessary steps from downloading camera trap images in the field to a quality checked data set ready to be used in ecological analyses. The workflow is implemented in R and includes (1) managing raw images, (2) automatic image classification, (3) quality check of automatic image labels, as well as the possibilities to (4) retrain the model with new images and to (5) manually review subsets of images to correct image labels. We illustrate the application of this workflow for the development of a new monitoring program of an Arctic small mammal community. We first trained a classification model for the specific small mammal community based on images from an initial set of camera traps. As the monitoring program evolved, the classification model was retrained with a small subset of images from new camera traps. This case study highlights the importance of model retraining in adaptive monitoring programs based on camera traps as this step in the workflow increases model performance and substantially decreases the total time needed for manually reviewing images and correcting image labels. We provide all R scripts to make the workflow accessible to other ecologists
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