2,390 research outputs found
On-chip Maxwell's demon as an information-powered refrigerator
We present an experimental realization of an autonomous Maxwell's Demon,
which extracts microscopic information from a System and reduces its entropy by
applying feedback. It is based on two capacitively coupled single electron
devices, both integrated on the same electronic circuit. This setup allows a
detailed analysis of the thermodynamics of both the Demon and the System as
well as their mutual information exchange. The operation of the Demon is
directly observed as a temperature drop in the System. We also observe a
simultaneous temperature rise in the Demon arising from the thermodynamic cost
of generating the mutual information.Comment: 10 pages, 7 figure
Road and railway verges serve as dispersal corridors for grassland plants
The role of linear habitat strips as dispersal corridors is a disputed topic. Reports concerning their significance for
animals have been contradictory, and the functions of corridors have been difficult to study in the case of sedentary
organisms such as plants. Previous studies on dispersal of plants along corridors have concentrated on a single
or a few species at a time. We developed a general method, a generalisation of the binomial test, for considering
dispersal or spatial relations of a large group of species. Particularly, we studied the ability of grassland plants
to spread along road and railway verges. Our data set consists of plant lists collected at study plots scattered
irregularly along road and railway networks. The dispersal ability was assessed by testing whether the species
composition at neighbouring sites – measured along roads and railways – reflects spatial dependence within each
species. Our result showed that similar combinations of grassland species occurred at neighbouring sites more often
than expected in a spatially independent case. We argue that management of verges and spatial autocorrelation of
environmental factors were not responsible for the result and thereby we conclude that grassland plants use road and
railway corridors for dispersal. This result is encouraging in regards to preservation of grassland plant populations.
Although semi-natural and natural grasslands have become scarce, road and railway embankments may partly
compensate for this loss, serving as substitute habitats and dispersal routes
Thermal conductance of a proximity superconductor
We study heat transport in hybrid normal metal - superconductor - normal
metal (NSN) structures. We find the thermal conductance of a short
superconducting wire to be strongly enhanced beyond the BCS value due to
inverse proximity effect. The measurements agree with a model based on the
quasiclassical theory of superconductivity in the diffusive limit. We determine
a crossover temperature below which quasiparticle heat conduction dominates
over the electron-phonon relaxation.Comment: 4+ pages, 3 figure
Acute and semi-chronic toxicity of vanadium tested on copepods of the species Temora longicornis
Metatarsophalangeal joint pain in psoriatic arthritis: a cross-sectional study
Methods. Thirty-four consecutive patients with PsA (mean age 45.3 years, 65% female, mean disease duration 9.9 years) and 22 control participants (mean age 37.9 years, 64% female) underwent clinical and US examination to determine the presence of pain, swelling, synovitis, erosions, effusions and submetatarsal bursae at the MTP joints. Mean barefoot peak plantar pressures were determined at each MTP joint. Levels of pain, US-determined pathology and peak pressures were compared between groups. Binary logistic regression was used to identify demographic, clinical examination-derived, US-derived and plantar pressure predictors of pain at the MTP joints in the PsA group.
Results. The presence of pain, deformity, synovitis, erosions (P < 0.001) and submetatarsal bursae and peak plantar pressure at MTP 3 (P < 0.05) were significantly higher in the PsA group. MTP joint pain in PsA was independently predicted by high BMI, female gender and the presence of joint subluxation, synovitis and erosion.
Conclusion. These results suggest local inflammatory and structural factors, together with systemic factors (gender, BMI), are predominantly responsible for painful MTP joints in PsA, with no clear role for plantar pressure characteristics
Laterally proximized aluminum tunnel junctions
This letter presents experiments on junctions fabricated by a technique that enables the use of high-quality aluminum oxide tunnel barriers with normal metal electrodes at low temperatures. Inverse proximity effect is applied to diminish the superconductivity of an aluminum dot through a clean lateral connection to a normal metal electrode. To demonstrate the effectiveness of this method, fully normal-state single electron transistors (SETs) and normal metal-insulator-superconductor (NIS) junctions applying proximized Aljunctions were fabricated. The transport characteristics of the junctions were similar to those obtained from standard theoreticalmodels of regular SETs and NIS junctions.Peer reviewe
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