440 research outputs found
Franz Huber's Neue Beobachtungen an den Bienen
2 BĂ€nde. Einheitssachtitel: Nouvelles observations sur les abeilles <dt.
Learning to Grasp: from Somewhere to Anywhere
Robotic grasping is still a partially solved, multidisciplinary problem where
data-driven techniques play an increasing role. The sparse nature of rewards
make the automatic generation of grasping datasets challenging, especially for
unconventional morphologies or highly actuated end-effectors. Most approaches
for obtaining large-scale datasets rely on numerous human-provided
demonstrations or heavily engineered solutions that do not scale well. Recent
advances in Quality-Diversity (QD) methods have investigated how to learn
object grasping at a specific pose with different robot morphologies. The
present work introduces a pipeline for adapting QD-generated trajectories to
new object poses. Using an RGB-D data stream, the vision pipeline first detects
the targeted object, predicts its 6-DOF pose, and finally tracks it. An
automatically generated reach-and-grasp trajectory can then be adapted by
projecting it relatively to the object frame. Hundreds of trajectories have
been deployed into the real world on several objects and with different robotic
setups: a Franka Research 3 with a parallel gripper and a UR5 with a dexterous
SIH Schunk hand. The transfer ratio obtained when applying transformation to
the object pose matches the one obtained when the object pose matches the
simulation, demonstrating the efficiency of the proposed approach
Resolving the A_{FB}^b puzzle in an extra dimensional model with an extended gauge structure
It is notorious that, contrary to all other precision electroweak data, the
forward-backward asymmetry for b quarks measured in Z decays at LEP1
is nearly three standard deviations away from the predicted value in the
Standard Model; significant deviations also occur in measurements of the
asymmetry off the Z pole. We show that these discrepancies can be resolved in a
variant of the Randall-Sundrum extra-dimensional model in which the gauge
structure is extended to to allow for
relatively light Kaluza-Klein excitations of the gauge bosons. In this
scenario, the fermions are localized differently along the extra dimension, in
order to generate the fermion mass hierarchies, so that the electroweak
interactions for the heavy third generation fermions are naturally different
from the light fermion ones. We show that the mixing between the Z boson with
the Kaluza-Klein excitations allows to explain the anomaly without
affecting (and even improving) the agreement of the other precision
observables, including the partial decay width, with experimental
data. Some implications of this scenario for the ILC are summarized.Comment: 23 pages, 5 figure
Enhanced equal frequency partition method for the identification of a water demand system
This paper deals with unsupervised partitioning. A first goal of this paper is to present an enhancement to the Equal Frequency Partition (EFP) method that allows to reduce, to some extent, the main drawback of this classical classification method, i.e. the data distribution dependency. A second goal of this work is to use the Enhanced Equal Frequency Partition (EEFP) method within the discretization process of the Fuzzy Inductive Reasoning (FIR) methodology for the identification of a model of a water demand system. It is shown that use of the EEFP method allows to obtain more accurate FIR models of the water demand system, reducing the prediction errors.Peer ReviewedPostprint (author's final draft
Rapid Bacteria Detection from Patients' Blood Bypassing Classical Bacterial Culturing
Sepsis is a life-threatening condition mostly caused by a bacterial infection resulting in inflammatory reaction and organ dysfunction if not treated effectively. Rapid identification of the causing bacterial pathogen already in the early stage of bacteremia is therefore vital. Current technologies still rely on time-consuming procedures including bacterial culturing up to 72 h. Our approach is based on ultra-rapid and highly sensitive nanomechanical sensor arrays. In measurements we observe two clearly distinguishable distributions consisting of samples with bacteria and without bacteria respectively. Compressive surface stress indicates the presence of bacteria. For this proof-of-concept, we extracted total RNA from EDTA whole blood samples from patients with blood-culture-confirmed bacteremia, which is the reference standard in diagnostics. We determined the presence or absence of bacterial RNA in the sample through 16S-rRNA hybridization and species-specific probes using nanomechanical sensor arrays. Via both probes, we identified two clinically highly-relevant bacterial species i.e., Escherichia coli and Staphylococcus aureus down to an equivalent of 20 CFU per milliliter EDTA whole blood. The dynamic range of three orders of magnitude covers most clinical cases. We correctly identified all patient samples regarding the presence or absence of bacteria. We envision our technology as an important contribution to early and sensitive sepsis diagnosis directly from blood without requirement for cultivation. This would be a game changer in diagnostics, as no commercial PCR or POCT device currently exists who can do this
Resonant tunneling through a C60 molecular junction in liquid environment
We present electronic transport measurements through thiolated C
molecules in liquid environment. The molecules were placed within a
mechanically controllable break junction using a single anchoring group per
molecule. When varying the electrode separation of the C-modified
junctions, we observed a peak in the conductance traces. The shape of the
curves is strongly influenced by the environment of the junction as shown by
measurements in two distinct solvents. In the framework of a simple resonant
tunneling model, we can extract the electronic tunneling rates governing the
transport properties of the junctions.Comment: 13 pages, 4 figures. To appear in Nanotechnolog
European Multidisciplinary and Water-Column Observatory - European Research Infrastructure Consortium (EMSO ERIC): challenges and opportunities for strategic European marine sciences
EMSO (European Multidisciplinary Seafloor and water-column Observatory,
www.emso-eu.org) is a largeâscale European Research Infrastructure I. It
is a distributed infrastructure of strategically placed, deepâsea seafloor and water
column observatory nodes with the essential scientific objective of realâtime, longterm
observation of environmental processes related to the interaction between the
geosphere, biosphere, and hydrosphere. The geographic locations of the EMSO observatory
nodes represent key sites in European waters, from the Arctic, through the
Atlantic and Mediterranean, to the Black Sea (Figure 1), as defined through previous
studies performed in FP6 and FP7 EC projects such as ESONETâCA, ESONETâNoE,
EMSO-PP (Person et al., 2015)Peer Reviewe
Impact of Intraoperative Fluid Balance and Norepinephrine on Postoperative Acute Kidney Injury after Cystectomy and Urinary Diversion over Two Decades: A Retrospective Observational Cohort Study.
The use of norepinephrine and the restriction of intraoperative hydration have gained increasing acceptance over the last few decades. Recently, there have been concerns regarding the impact of this approach on renal function. The objective of this study was to examine the influence of norepinephrine, intraoperative fluid administration and their interaction on acute kidney injury (AKI) after cystectomy. In our cohort of 1488 consecutive patients scheduled for cystectomies and urinary diversions, the overall incidence of AKI was 21.6% (95%-CI: 19.6% to 23.8%) and increased by an average of 0.6% (95%-CI: 0.1% to 1.1%, p = 0.025) per year since 2000. The fluid and vasopressor regimes were characterized by an annual decrease in fluid balance (-0.24 mL·kg-1·h-1, 95%-CI: -0.26 to -0.22, p < 0.001) and an annual increase in the amount of norepinephrine of 0.002 ”g·kg-1·min-1 (95%-CI: 0.0016 to 0.0024, p < 0.001). The interaction between the fluid balance and norepinephrine levels resulted in a U-shaped association with the risk of AKI; however, the magnitude and shape depended on the reference categories of confounders (age and BMI). We conclude that decreased intraoperative fluid balance combined with increased norepinephrine administration was associated with an increased risk of AKI. However, other potential drivers of the observed increase in AKI incidence need to be further investigated in the future
Hybrid Targeted/Untargeted Screening Method for the Determination of Wildfire and Water-Soluble Organic Tracers in Ice Cores and Snow.
Wildfires can influence the earth's radiative forcing through the emission of biomass-burning aerosols. To better constrain the impacts of wildfires on climate and understand their evolution under future climate scenarios, reconstructing their chemical nature, assessing their past variability, and evaluating their influence on the atmospheric composition are essential. Ice cores are unique to perform such reconstructions representing archives not only of past biomass-burning events but also of concurrent climate and environmental changes. Here, we present a novel methodology for the quantification of five biomass-burning proxies (syringic acid, vanillic acid, vanillin, syringaldehyde, and p-hydroxybenzoic acid) and one biogenic emission proxy (pinic acid) using solid phase extraction (SPE) and ultrahigh-performance liquid chromatography coupled with high-resolution mass spectrometry. This method was also optimized for untargeted screening analysis to gain a broader knowledge about the chemical composition of organic aerosols in ice and snow samples. The method provides low detection limits (0.003-0.012 ng g-1), high recoveries (74 ± 10%), and excellent reproducibility, allowing the quantification of the six proxies and the identification of 313 different molecules, mainly constituted by carbon, hydrogen, and oxygen. The effectiveness of two different sample storage strategies, i.e., re-freezing of previously molten ice samples and freezing of previously loaded SPE cartridges, was also assessed, showing that the latter approach provides more reproducible results
Modeling Social-Ecological Feedback Effects in the Implementation of Payments for Environmental Services in Pasture-Woodlands
International audienceAn effective implementation of payment for environmental services (PES) must allow for complex interactions of coupled social-ecological systems. We present an integrative study of the pasture-woodland landscape of the Swiss Jura Mountains combining methods from natural and social sciences to explore feedback between vegetation dynamics on paddock level, farm-based decision making, and policy decisions on the national political level. Our modeling results show that concomitant climatic and socioeconomic changes advance the loss of open grassland in silvopastoral landscapes. This would, in the longer term, deteriorate the historical wooded pastures in the region, which fulfill important functions for biodiversity and are widely considered as landscapes that deserve protection. Payment for environmental services could counteract this development while respecting historical land-use and ecological boundary conditions. The assessed policy feedback process reveals that current policy processes may hinder the implementation of PES, even though a payment for the upkeep of wooded pasture would generally enjoy the backing of the relevant policy network. To effectively support the upkeep of the wooded pastures in the Jura, concomitant policy changes, such as market deregulation, must also be taken into account
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