2,169 research outputs found
Dynamic similarity promotes interpersonal coordination in joint-action
Human movement has been studied for decades and dynamic laws of motion that
are common to all humans have been derived. Yet, every individual moves
differently from everyone else (faster/slower, harder/smoother etc). We propose
here an index of such variability, namely an individual motor signature (IMS)
able to capture the subtle differences in the way each of us moves. We show
that the IMS of a person is time-invariant and that it significantly differs
from those of other individuals. This allows us to quantify the dynamic
similarity, a measure of rapport between dynamics of different individuals'
movements, and demonstrate that it facilitates coordination during interaction.
We use our measure to confirm a key prediction of the theory of similarity that
coordination between two individuals performing a joint-action task is higher
if their motions share similar dynamic features. Furthermore, we use a virtual
avatar driven by an interactive cognitive architecture based on feedback
control theory to explore the effects of different kinematic features of the
avatar motion on the coordination with human players
Early treatment failure during treatment of Plasmodium falciparum malaria with atovaquone-proguanil in the Republic of Ivory Coast
The increased spread of drug-resistant malaria highlights the need for alternative drugs for treatment and chemoprophylaxis. The combination of atovaquoneâproguanil (MalaroneÂź) has shown high efficacy against Plasmodium falciparum with only mild side-effects. Treatment failures have been attributed to suboptimal dosages or to parasite resistance resulting from a point mutation in the cytochrome b gene. In this paper, a case of early treatment failure was reported in a patient treated with atovaquone-proguanil; this failure was not associated with a mutation in the parasite cytochrome b gene, with impaired drug bioavailability, or with re-infection
Assessing forest availability for wood supply in Europe
The quantification of forests available for wood supply (FAWS) is essential for decision-making with regard to
the maintenance and enhancement of forest resources and their contribution to the global carbon cycle. The
provision of harmonized forest statistics is necessary for the development of forest associated policies and to
support decision-making. Based on the National Forest Inventory (NFI) data from 13 European countries, we
quantify and compare the areas and aboveground dry biomass (AGB) of FAWS and forest not available for wood
supply (FNAWS) according to national and reference definitions by determining the restrictions and associated
thresholds considered at country level to classify forests as FAWS or FNAWS.
FAWS represent between 75 and 95 % of forest area and AGB for most of the countries in this study. Economic
restrictions are the main factor limiting the availability of forests for wood supply, accounting for 67 % of the
total FNAWS area and 56 % of the total FNAWS AGB, followed by environmental restrictions. Profitability, slope
and accessibility as economic restrictions, and protected areas as environmental restrictions are the factors most
frequently considered to distinguish between FAWS and FNAWS. With respect to the area of FNAWS associated
with each type of restriction, an overlap among the restrictions of 13.7 % was identified. For most countries, the differences in the FNAWS areas and AGB estimates between national and reference definitions ranged from 0 to
5 %. These results highlight the applicability and reliability of a FAWS reference definition for most of the
European countries studied, thereby facilitating a consistent approach to assess forests available for supply for
the purpose of international reportinginfo:eu-repo/semantics/publishedVersio
Gemini multi-conjugate adaptive optics system review II: Commissioning, operation and overall performance
The Gemini Multi-conjugate Adaptive Optics System - GeMS, a facility
instrument mounted on the Gemini South telescope, delivers a uniform, near
diffraction limited images at near infrared wavelengths (0.95 microns- 2.5
microns) over a field of view of 120 arc seconds. GeMS is the first sodium
layer based multi laser guide star adaptive optics system used in astronomy. It
uses five laser guide stars distributed on a 60 arc seconds square
constellation to measure for atmospheric distortions and two deformable mirrors
to compensate for it. In this paper, the second devoted to describe the GeMS
project, we present the commissioning, overall performance and operational
scheme of GeMS. Performance of each sub-system is derived from the
commissioning results. The typical image quality, expressed in full with half
maximum, Strehl ratios and variations over the field delivered by the system
are then described. A discussion of the main contributor to performance
limitation is carried-out. Finally, overheads and future system upgrades are
described.Comment: 20 pages, 11 figures, accepted for publication in MNRA
Understanding the growth mechanism of BaZrS chalcogenide perovskite thin films from sulfurized oxide precursors
Barium zirconium sulfide (BaZrS) is an earth-abundant and environmentally
friendly chalcogenide perovskite with promising properties for various energy
conversion applications. Recently, sulfurization of oxide precursors has been
suggested as a viable solution for effective synthesis, especially from the
perspective of circumventing the difficulty of handling alkali earth metals. In
this work, we explore in detail the synthesis of BaZrS from Ba-Zr-O oxide
precursor films sulfurized at temperatures ranging from 700 C to 1000
C. We propose a formation mechanism of BaZrS based on a two-step
reaction involving an intermediate amorphization step of the BaZrO3 crystalline
phase. We show how the diffusion of sulfur (S) species in the film is the
rate-limiting step of this reaction. The processing temperature plays a key
role in determining the total fraction of conversion from oxide to sulfide
phase at a constant flow rate of the sulfur-containing H2S gas used as a
reactant. Finally, we observe the formation of stoichiometric BaZrS
(1:1:3), even under Zr-rich precursor conditions, with the formation of ZrO
as a secondary phase. This marks BaZrS quite unique among the other types
of chalcogenides, such as chalcopyrites and kesterites, which can instead
accommodate quite a large range of non-stoichiometric compositions. This work
opens up a pathway for further optimization of the BaZrS synthesis process,
straightening the route towards future applications of this material.Comment: Equal contributio
Metformin lowers Glucose 6-phosphate in hepatocytes by activation of glycolysis downstream of glucose phosphorylation
The chronic effects of metformin on liver gluconeogenesis involve repression of the G6pc gene, which is regulated by the carbohydrate-response element-binding protein through raised cellular intermediates of glucose metabolism. In this study we determined the candidate mechanisms by which metformin lowers glucose 6-phosphate (G6P) in mouse and rat hepatocytes challenged with high glucose or gluconeogenic precursors. Cell metformin loads in the therapeutic range lowered cell G6P but not ATP and decreased G6pc mRNA at high glucose. The G6P lowering by metformin was mimicked by a complex 1 inhibitor (rotenone) and an uncoupler (dinitrophenol) and by overexpression of mGPDH, which lowers glycerol 3-phosphate and G6P and also mimics the G6pc repression by metformin. In contrast, direct allosteric activators of AMPK (A-769662, 991, and C-13) had opposite effects from metformin on glycolysis, gluconeogenesis, and cell G6P. The G6P lowering by metformin, which also occurs in hepatocytes from AMPK knockout mice, is best explained by allosteric regulation of phosphofructokinase-1 and/or fructose bisphosphatase-1, as supported by increased metabolism of [3-3H]glucose relative to [2-3H]glucose; by an increase in the lactate m2/m1 isotopolog ratio from [1,2-13C2]glucose; by lowering of glycerol 3-phosphate an allosteric inhibitor of phosphofructokinase-1; and by marked G6P elevation by selective inhibition of phosphofructokinase-1; but not by a more reduced cytoplasmic NADH/NAD redox state. We conclude that therapeutically relevant doses of metformin lower G6P in hepatocytes challenged with high glucose by stimulation of glycolysis by an AMP-activated protein kinase-independent mechanism through changes in allosteric effectors of phosphofructokinase-1 and fructose bisphosphatase-1, including AMP, Pi, and glycerol 3-phosphate
Unravelling socio-motor biomarkers in schizophrenia
We present novel, low-cost and non-invasive potential diagnostic biomarkers of schizophrenia. They are based on the âmirror-gameâ, a coordination task in which two partners are asked to mimic each otherâs hand movements. In particular, we use the patientâs solo movement, recorded in the absence of a partner, and motion recorded during interaction with an artificial agent, a computer avatar or a humanoid robot. In order to discriminate between the patients and controls, we employ statistical learning techniques, which we apply to nonverbal synchrony and neuromotor features derived from the participantsâ movement data. The proposed classifier has 93% accuracy and 100% specificity. Our results provide evidence that statistical learning techniques, nonverbal movement coordination and neuromotor characteristics could form the foundation of decision support tools aiding clinicians in cases of diagnostic uncertainty
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