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Ontogenetic changes in cutaneous and branchial ionocytes and morphology in yellowfin tuna (Thunnus albacares) larvae.
The development of osmoregulatory and gas exchange organs was studied in larval yellowfin tuna (Thunnus albacares) from 2 to 25 days post-hatching (2.9-24.5 mm standard length, SL). Cutaneous and branchial ionocytes were identified using Na+/K+-ATPase immunostaining and scanning electron microscopy. Cutaneous ionocyte abundance significantly increased with SL, but a reduction in ionocyte size and density resulted in a significant decrease in relative ionocyte area. Cutaneous ionocytes in preflexion larvae had a wide apical opening with extended microvilli; however, microvilli retracted into an apical pit from flexion onward. Lamellae in the gill and pseudobranch were first detected ~ 3.3 mm SL. Ionocytes were always present on the gill arch, first appeared in the filaments and lamellae of the pseudobranch at 3.4 mm SL, and later in gill filaments at 4.2 mm SL, but were never observed in the gill lamellae. Unlike the cutaneous ionocytes, gill and pseudobranch ionocytes had a wide apical opening with extended microvilli throughout larval development. The interlamellar fusion, a specialized gill structure binding the lamellae of ram-ventilating fish, began forming by ~ 24.5 mm SL and contained ionocytes, a localization never before reported. Ionocytes were retained on the lamellar fusions and also found on the filament fusions of larger sub-adult yellowfin tuna; however, sub-adult gill ionocytes had apical pits. These results indicate a shift in gas exchange and NaCl secretion from the skin to branchial organs around the flexion stage, and reveal novel aspects of ionocyte localization and morphology in ram-ventilating fishes
Robust Change-Point Detection for Functional Time Series Based on -Statistics and Dependent Wild Bootstrap
The aim of this paper is to develop a change-point test for functional time
series that uses the full functional information and is less sensitive to
outliers compared to the classical CUSUM test. For this aim, the Wilcoxon
two-sample test is generalized to functional data. To obtain the asymptotic
distribution of the test statistic, we proof a limit theorem for a process of
-statistics with values in a Hilbert space under weak dependence. Critical
values can be obtained by a newly developed version of the dependent wild
bootstrap for non-degenerate 2-sample -statistics
Learning Aerial Image Segmentation from Online Maps
This study deals with semantic segmentation of high-resolution (aerial)
images where a semantic class label is assigned to each pixel via supervised
classification as a basis for automatic map generation. Recently, deep
convolutional neural networks (CNNs) have shown impressive performance and have
quickly become the de-facto standard for semantic segmentation, with the added
benefit that task-specific feature design is no longer necessary. However, a
major downside of deep learning methods is that they are extremely data-hungry,
thus aggravating the perennial bottleneck of supervised classification, to
obtain enough annotated training data. On the other hand, it has been observed
that they are rather robust against noise in the training labels. This opens up
the intriguing possibility to avoid annotating huge amounts of training data,
and instead train the classifier from existing legacy data or crowd-sourced
maps which can exhibit high levels of noise. The question addressed in this
paper is: can training with large-scale, publicly available labels replace a
substantial part of the manual labeling effort and still achieve sufficient
performance? Such data will inevitably contain a significant portion of errors,
but in return virtually unlimited quantities of it are available in larger
parts of the world. We adapt a state-of-the-art CNN architecture for semantic
segmentation of buildings and roads in aerial images, and compare its
performance when using different training data sets, ranging from manually
labeled, pixel-accurate ground truth of the same city to automatic training
data derived from OpenStreetMap data from distant locations. We report our
results that indicate that satisfying performance can be obtained with
significantly less manual annotation effort, by exploiting noisy large-scale
training data.Comment: Published in IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSIN
Innate versus adaptive immunity in sticklebacks: evidence for trade-offs from a selection experiment
In vertebrates, the immune system consists of two arms of different characteristics: the innate and the acquired immune response. Parasites that are only shortly exposed to the immune system are most efficiently attacked by fast, constitutive innate immune mechanisms. Here, we experimentally selected within four fish families for high innate resistance versus susceptibility of three-spined sticklebacks (Gasterosteus aculeatus) against infection with the eye-fluke (Diplostomum pseudospathacaeum), a parasite whose metacercariae are protected from the immune system within the eye lens. We predicted that in families with high susceptibility, the adaptive immune system would be upregulated when challenged with infection. In accordance, we found that MHC class IIB expression is increased by approximately 50% in those lines selected for higher parasite load (i.e. low innate response). This suggests extensive genetic correlations between innate and adaptive immune system and/or crosstalk between both lines of defense. An efficient, specific innate immune response might reduce overall activation of the immune system and potentially alleviate associated effects of immunopatholog
Hybridisation at the organic-metal interface: a surface-scientific analogue of H\"uckel's rule?
We demonstrate that cyclooctatetraene (COT) can be stabilised in different
conformations when adsorbed on different noble-metal surfaces due to varying
molecule-substrate interaction. While at first glance the behaviour seems to be
in accordance with H\"uckel's rule, a theoretical analysis reveals no
significant charge transfer. The driving mechanism for the conformational
change is hybridisation at the organic-metal interface and does not necessitate
any charge transfer.Comment: Accepted for publication in Chemical Communications. Main article: 6
pages, 2 figures; Supplementary Information: 4 pages, 3 figures, 1 table. All
in one fil
Heaping, Secondary Flows and Broken Symmetry in Flows of Elongated Granular Particles
In this paper we report experiments where we shear granular rods in
split-bottom geometries, and find that a significant heap of height of least
40% of the filling height can form at the particle surface. We show that
heaping is caused by a significant secondary flow, absent for spherical
particles. Flow reversal transiently reverses the secondary flow, leading to a
quick collapse and slower regeneration of the heap. We present a symmetry
argument and experimental data that show that the generation of the secondary
flow is driven by a misalignment of the mean particle orientation with the
streamlines of the flow. This general mechanism is expected to be important in
all flows of sufficiently anisometric grains.Comment: Accepted for Soft Matte
The asymmetric single-impurity Anderson model - the modified perturbation theory
We investigate the single-impurity Anderson model by means of the recently
introduced modified perturbation theory. This approximation scheme yields
reasonable results away from the symmetric case. The agreement with exactly
known results for the symmetric case is checked, and results for the
non-symmetric case are presented. With decreasing conduction band occupation,
the breakdown of the screening of the local moment is observed. In the
crossover regime between Kondo limit and mixed-valence regime, an enhanced
zero-temperature susceptibility is found.Comment: 7 pages, 7 figures, to appear in Physica
Bericht für das Projekt „Ernährermodell“
Das Working Paper gibt die Ergebnisse einer Analyse ausgewählter deutscher
Tageszeitungen (eher konsevativer und eher linksgerichteter) wieder. Zum Teil
bestätigt sich dadurch die Annahme, dass die Einstandspflichten von Paaren in
der Diskussion um die EinfĂĽhrung des SGB II, im Volksmund "Hartz IV" genannt,
in ihrer Brisanz der Ă–ffentlichkeit ĂĽberhaupt erst klargemacht wurden und
Kritik daran geäußert wurde, zum Teil zeigt sich aber auch, dass die
Vergemeinschaftung von Paaren, selbst wenn sie nicht verheiratet sind, zum
normativen Repertoire konservativer Affirmation gehört und nicht auf
rechtsethische Voraussetzungen und rechtssoziologische Auswirkungen hin
ĂĽberprĂĽft wird. Durch die Problematisierung in "linksgerichteten" Zeitungen
dürfte die Selbstverständlichkeit der Affirmation jedoch etwas gemindert
worden sein
Operating Power Grids with Few Flow Control Buses
Future power grids will offer enhanced controllability due to the increased
availability of power flow control units (FACTS). As the installation of
control units in the grid is an expensive investment, we are interested in
using few controllers to achieve high controllability. In particular, two
questions arise: How many flow control buses are necessary to obtain globally
optimal power flows? And if fewer flow control buses are available, what can we
achieve with them? Using steady state IEEE benchmark data sets, we explore
experimentally that already a small number of controllers placed at certain
grid buses suffices to achieve globally optimal power flows. We present a
graph-theoretic explanation for this behavior. To answer the second question we
perform a set of experiments that explore the existence and costs of feasible
power flow solutions at increased loads with respect to the number of flow
control buses in the grid. We observe that adding a small number of flow
control buses reduces the flow costs and extends the existence of feasible
solutions at increased load.Comment: extended version of an ACM e-Energy 2015 poster/workshop pape
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