159 research outputs found
Unbalanced Multi-Marginal Optimal Transport
Entropy regularized optimal transport and its multi-marginal generalization
have attracted increasing attention in various applications, in particular due
to efficient Sinkhorn-like algorithms for computing optimal transport plans.
However, it is often desirable that the marginals of the optimal transport plan
do not match the given measures exactly, which led to the introduction of the
so-called unbalanced optimal transport. Since unbalanced methods were not
examined for the multi-marginal setting so far, we address this topic in the
present paper. More precisely, we introduce the unbalanced multi-marginal
optimal transport problem and its dual, and show that a unique optimal
transport plan exists under mild assumptions. Further, we generalize the
Sinkhorn algorithm for regularized unbalanced optimal transport to the
multi-marginal setting and prove its convergence. If the cost function
decouples according to a tree, the iterates can be computed efficiently. At the
end, we discuss three applications of our framework, namely two barycenter
problems and a transfer operator approach, where we establish a relation
between the barycenter problem and the multi-marginal optimal transport with an
appropriate tree-structured cost function
BARLEX â the Barley Draft Genome Explorer
Colmsee C, Beier S, Himmelbach A, et al. BARLEX â the Barley Draft Genome Explorer. Molecular Plant. 2015;8(6):964-966
Design of an imaging spectrometer for Earth observation using freeform mirrors
Design of an imaging spectrometer for earth observation using freeform mirrors
Thomas Peschel1, Christoph Damm1, Matthias Beier1, Andreas Gebhard1, Stefan Risse1, Ingo Walter2, Ilse Sebastian2, David Krutz2
1 Fraunhofer Institut fĂŒr Angewandte Optik und Feinwerktechnik, Jena
2 DLR, Institut fĂŒr Optische Sensorsysteme, Berlin
In 2017 the new hyperspectral DLR Earth Sensing Imaging Spectrometer (DESIS) will be integrated in the Multi-User-System for Earth Sensing (MUSES) platform /1/ installed on the International Space Station (ISS).
The DESIS instrument is developed under the responsibility of the DLR. It will deliver images of the earth with a spatial resolution of 30 m on ground in 235 spectral channels in the wavelength range from 400 nm to 1 ”m.
As partner of the development team Fraunhofer IOF is responsible for the optical system of the imaging spectrometer.The optical system is made of two primary components: A compact Three-Mirror-Anastigmat (TMA) telescope images the ground strip under observation onto a slit. The following spectrometer reimages the slit onto the detector and performs the spectral separation using a reflective grating.
The whole optical system is realized using metal-based mirrors the surfaces of which are made by Single-Point-Diamond Turning (SPDT). Since the spectral range is in the visible, a post-processing of the surfaces by Nickel plating is necessary. The final surface shape and roughness are realized by a second SPDT step and subsequent Magneto-Rheological Finishing.
The TMA provides a focal length of 320 mm and an aperture of F/2.8. Its mechanical design relies on the Duolith-technology of IOF as well as optical and mechanical reference structures on the mirrors /2/ manufactured in the same SPDT run. This strategy allows for a significantly simplified adjustment of the optical system /3/.
The spectrometer was designed on the basis of the so-called Offner scheme. Because of the high aperture of the system a freeform mirror had to be introduced in order to provide a good imaging quality over the whole spectral range.
The above optical design requires a grating on a curved surface. Technologies are developed in order to fabricate the grating either by SPDT or, alternatively, by laser lithography.
The mechanical design uses light-weight housing elements which wrap the optical path to suppress stray light. An athermal design is provided by using the same metal for mirrors and housing. To provide high adjustment precision, the housing elements carry reference and mounting features made by SPDT as well. This approach allows for a stiff mechanical set-up of the system, which is compatible with the harsh requirements of a space flight.
References:
1 N. Humphrey, âA View From Above: Imaging from the ISSâ, Teledyne DALSA 2014, http://possibility.teledynedalsa.com/a-view-from-above/
2 S. Scheiding, e.a., âUltra-precisely manufactured mirror assemblies with well-defined reference structuresâ, Proc. SPIE 7739, 2010.
3 T. Peschel, e.a., âAnamorphotic telescope for earth observation in the mid-infrared rangeâ, ICSO 201
Neural processing associated with cognitive empathy in pedophilia and child sexual offending
Behavioral studies found evidence for superior cognitive empathy (CE) in pedophilic men without a history of child sexual offending (P - CSO) compared to pedophilic men with a history of child sexual offending (P + CSO). Functional magnetic resonance imaging (fMRI) studies also point to differences between P - CSO and P + CSO. Neural processing associated with CE has not yet been investigated. Therefore, the present study aimed to explore the neural correlates of CE in subjects with pedophilia with (P + CSO) and without (P - CSO) child sexual offending. 15 P + CSO, 15 P - CSO and 24 teleiophilic male controls (TC) performed a CE task during fMRI. We observed reduced activation in the left precuneus (Pcu) and increased activation in the left anterior cingulate cortex (ACC) in P - CSO compared to P + CSO. P - CSO also showed stronger connectivity between these regions, which might reflect a top-down modulation of the Pcu by the ACC toward an increased self-focused emotional reaction in social situations. There was also evidence for increased right superior temporal gyrus activation in P - CSO that might constitute a potentially compensatory recruitment due to the dampened Pcu activation. These findings provide first evidence for altered neural processing of CE in P - CSO and underline the importance of addressing CE in pedophilia and CSO in order to uncover processes relevant to effective prevention of child sexual abuse
A homolog of <i>blade-on-petiole</i> <i>1</i> and <i>2</i> (<i>BOP1/2</i>) controls internode length and homeotic changes of the barley inflorescence
Inflorescence architecture in small-grain cereals has a direct effect on yield and is an important selection target in breeding for yield improvement. We analyzed the recessive mutation laxatum-a (lax-a) in barley (Hordeum vulgare), which causes pleiotropic changes in spike development, resulting in (1) extended rachis internodes conferring a more relaxed inflorescence, (2) broadened base of the lemma awns, (3) thinner grains that are largely exposed due to reduced marginal growth of the palea and lemma, and (4) and homeotic conversion of lodicules into two stamenoid structures. Map-based cloning enforced by mapping-by-sequencing of the mutant lax-a locus enabled the identification of a homolog of BLADE-ON-PETIOLE1 (BOP1) and BOP2 as the causal gene. Interestingly, the recently identified barley uniculme4 gene also is a BOP1/2 homolog and has been shown to regulate tillering and leaf sheath development. While the Arabidopsis (Arabidopsis thaliana) BOP1 and BOP2 genes act redundantly, the barley genes contribute independent effects in specifying the developmental growth of vegetative and reproductive organs, respectively. Analysis of natural genetic diversity revealed strikingly different haplotype diversity for the two paralogous barley genes, likely affected by the respective genomic environments, since no indication for an active selection process was detected
Effects of Climate and Atmospheric Nitrogen Deposition on Early to Mid-Term Stage Litter Decomposition Across Biomes
Litter decomposition is a key process for carbon and nutrient cycling in terrestrial ecosystems and is mainly controlled by environmental conditions, substrate quantity and quality as well as microbial community abundance and composition. In particular, the effects of climate and atmospheric nitrogen (N) deposition on litter decomposition and its temporal dynamics are of significant importance, since their effects might change over the course of the decomposition process. Within the TeaComposition initiative, we incubated Green and Rooibos teas at 524 sites across nine biomes. We assessed how macroclimate and atmospheric inorganic N deposition under current and predicted scenarios (RCP 2.6, RCP 8.5) might affect litter mass loss measured after 3 and 12 months. Our study shows that the early to mid-term mass loss at the global scale was affected predominantly by litter quality (explaining 73% and 62% of the total variance after 3 and 12 months, respectively) followed by climate and N deposition. The effects of climate were not litter-specific and became increasingly significant as decomposition progressed, with MAP explaining 2% and MAT 4% of the variation after 12 months of incubation. The effect of N deposition was litter-specific, and significant only for 12-month decomposition of Rooibos tea at the global scale. However, in the temperate biome where atmospheric N deposition rates are relatively high, the 12-month mass loss of Green and Rooibos teas decreased significantly with increasing N deposition, explaining 9.5% and 1.1% of the variance, respectively. The expected changes in macroclimate and N deposition at the global scale by the end of this century are estimated to increase the 12-month mass loss of easily decomposable litter by 1.1-3.5% and of the more stable substrates by 3.8-10.6%, relative to current mass loss. In contrast, expected changes in atmospheric N deposition will decrease the mid-term mass loss of high-quality litter by 1.4-2.2% and that of low-quality litter by 0.9-1.5% in the temperate biome. Our results suggest that projected increases in N deposition may have the capacity to dampen the climate-driven increases in litter decomposition depending on the biome and decomposition stage of substrate.Peer reviewe
The atypical kinase RIOK1 promotes tumor growth and invasive behavior
Despite being overexpressed in different tumor entities, RIO kinases are hardly characterized in mammalian cells. We investigated the role of these atypical kinases in different cancer cells. Using isogenic colon-, breast- and lung cancer cell lines, we demonstrate that knockdown of RIOK1, but not of RIOK2 or RIOK3, strongly impairs proliferation and invasiveness in conventional and 3D culture systems. Interestingly, these effects were mainly observed in RAS mutant cancer cells. In contrast, growth of RAS wildtype Caco-2 and Bcr-Abl-driven K562 cells is not affected by RIOK1 knockdown, suggesting a specific requirement for RIOK1 in the context of oncogenic RAS signaling. Furthermore, we show that RIOK1 activates NF-ÎșB signaling and promotes cell cycle progression. Using proteomics, we identified the pro-invasive proteins Metadherin and Stathmin1 to be regulated by RIOK1. Additionally, we demonstrate that RIOK1 promotes lung colonization in vivo and that RIOK1 is overexpressed in different subtypes of human lung- and breast cancer. Altogether, our data suggest RIOK1 as a potential therapeutic target, especially in RAS-driven cancers
Two Sides of One Coin: A Comparison of Clinical and Neurobiological Characteristics of Convicted and Non-Convicted Pedophilic Child Sexual Offenders
High prevalence of child sexual offending stand in contradiction to low conviction rates (one-tenth at most) of child sexual offenders (CSOs). Little is known about possible differences between convicted and non-convicted pedophilic CSOs and why only some become known to the judicial system. This investigation takes a closer look at the two sides of "child sexual offending" by focusing on clinical and neurobiological characteristics of convicted and non-convicted pedophilic CSOs as presented in the Neural Mechanisms Underlying Pedophilia and sexual offending against children (NeMUP)*-study. Seventy-nine male pedophilic CSOs were examined, 48 of them convicted. All participants received a thorough clinical examination including the structured clinical interview (SCID), intelligence, empathy, impulsivity, and criminal history. Sixty-one participants (38 convicted) underwent an inhibition performance task (Go/No-go paradigm) combined with functional magnetic resonance imaging (fMRI). Convicted and non-convicted pedophilic CSOs revealed similar clinical characteristics, inhibition performances, and neuronal activation. However, convicted subjects' age preference was lower (i.e., higher interest in prepubescent children) and they had committed a significantly higher number of sexual offenses against children compared to non-convicted subjects. In conclusion, sexual age preference may represent one of the major driving forces for elevated rates of sexual offenses against children in this sample, and careful clinical assessment thereof should be incorporated in every preventive approach
Negative Regulation of Bone Formation by the Transmembrane Wnt Antagonist Kremen-2
Wnt signalling is a key pathway controlling bone formation in mice and humans. One of the regulators of this pathway is Dkk1, which antagonizes Wnt signalling through the formation of a ternary complex with the transmembrane receptors Krm1/2 and Lrp5/6, thereby blocking the induction of Wnt signalling by the latter ones. Here we show that Kremen-2 (Krm2) is predominantly expressed in bone, and that its osteoblast-specific over-expression in transgenic mice (Col1a1-Krm2) results in severe osteoporosis. Histomorphometric analysis revealed that osteoblast maturation and bone formation are disturbed in Col1a1-Krm2 mice, whereas bone resorption is increased. In line with these findings, primary osteoblasts derived from Col1a1-Krm2 mice display a cell-autonomous differentiation defect, impaired canonical Wnt signalling and decreased production of the osteoclast inhibitory factor Opg. To determine whether the observed effects of Krm2 on bone remodeling are physiologically relevant, we analyzed the skeletal phenotype of 24 weeks old Krm2-deficient mice and observed high bone mass caused by a more than three-fold increase in bone formation. Taken together, these data identify Krm2 as a regulator of bone remodeling and raise the possibility that antagonizing KRM2 might prove beneficial in patients with bone loss disorders
Seismogenic faults, landslides, and associated tsunamis off southern Italy - Cruise No. M86/2, December 27, 2011 - January 17, 2012, Cartagena (Spain) - Brindisi (Italy)
Summary
The continental margins of southern Italy are located along converging plate boundaries, which
are affected by intense seismicity and volcanic activity. Most of the coastal areas experienced
severe earthquakes, landslides, and tsunamis in historical and/or modern times. The most
prominent example is the Messina earthquake of Dec. 28, 1908 (Ms=7.3; 80,000 casualties),
which was characterized by the worst tsunami Italy experienced in the historical time (~2000
casualties). It is, however, still unclear, whether this tsunami was triggered by a sudden vertical
movement along a major fault during the earthquake or as a result of a giant marine slide
initiated by the earthquake. The recurrence rates of major landslides and therefore the risk
associated with landslides is also unknown. Based on detailed bathymetric data sets collected by
Italian colleagues in the frame of the MaGIC Project (Marine Geohazards along the Italian
Coast), we collected seismic data (2D and 3D) and gravity cores in three working areas (The
Messina Straits, off Eastern Sicily, the Gioia Basin). A dense grid of new 2D-seismic data in the
Messina Straits will allow to map fault patterns in great detail. One interesting outcome in this
context is the identification of a set of normal faults striking in an EW-direction, which is almost
perpendicular to the previously postulated faults. This EW-striking faults seem to be active. The
area off eastern Sicily is characterized by numerous landslides and a complex deformation
pattern. A 3D-seismic data set has been collected during the cruise using the so called P-cable in
order to investigate these deformation patterns in detail. The new data will be the basis for a risk
assessment in the working areas
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