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Somatosensory input generated by one's actions (i.e., self-initiated body movements) is generally attenuated. Conversely, externally caused somatosensory input is enhanced, for example, during active touch and the haptic exploration of objects. Here, we used functional magnetic resonance imaging (fMRI) to ask how the brain accomplishes this delicate weighting of self-generated versus externally caused somatosensory components. Finger movements were either self-generated by our participants or induced by functional electrical stimulation (FES) of the same muscles. During half of the trials, electrotactile impulses were administered when the (actively or passively) moving finger reached a predefined flexion threshold. fMRI revealed an interaction effect in the contralateral posterior insular cortex (pIC), which responded more strongly to touch during self-generated than during FES-induced movements. A network analysis via dynamic causal modeling revealed that connectivity from the secondary somatosensory cortex via the pIC to the supplementary motor area was generally attenuated during self-generated relative to FES-induced movements-yet specifically enhanced by touch received during self-generated, but not FES-induced movements. Together, these results suggest a crucial role of the parietal operculum and the posterior insula in differentiating self-generated from externally caused somatosensory information received from one's moving limb.
In two experiments, we compared the dynamics of corticospinal excitability when processing visually or linguistically presented tool-oriented hand actions in native speakers and sequential bilinguals. In a third experiment we used the same procedure to test non-motor, low-level stimuli, i.e. scrambled images and pseudo-words.
Stimuli were presented in sequence: pictures (tool + tool-oriented hand action or their scrambled counterpart) and words (tool noun + tool-action verb or pseudo-words). Experiment 1 presented German linguistic stimuli to native speakers, while Experiment 2 presented English stimuli to non-natives. Experiment 3 tested Italian native speakers. Single-pulse trascranial magnetic stimulation (spTMS) was applied to the left motor cortex at five different timings: baseline, 200 ms after tool/noun onset, 150, 350 and 500 ms after hand/verb onset with motor-evoked potentials (MEPs) recorded from the first dorsal interosseous (FDI) and abductor digiti minimi (ADM) muscles.
We report strong similarities in the dynamics of corticospinal excitability across the visual and linguistic modalities. MEPs' suppression started as early as 150 ms and lasted for the duration of stimulus presentation (500 ms). Moreover, we show that this modulation is absent for stimuli with no motor content. Overall, our study supports the notion of a core, overarching system of action semantics shared by different modalities.
This paper investigates the predictions of the Derivational Complexity Hypothesis by studying the acquisition of wh-questions in 4- and 5-year-old Akan-speaking children in an experimental approach using an elicited production and an elicited imitation task. Akan has two types of wh-question structures (wh-in-situ and wh-ex-situ questions), which allows an investigation of children’s acquisition of these two question structures and their preferences for one or the other. Our results show that adults prefer to use wh-ex-situ questions over wh-in-situ questions. The results from the children show that both age groups have the two question structures in their linguistic repertoire. However, they differ in their preferences in usage in the elicited production task: while the 5-year-olds preferred the wh-in-situ structure over the wh-ex-situ structure, the 4-year-olds showed a selective preference for the wh-in-situ structure in who-questions. These findings suggest a developmental change in wh-question preferences in Akan-learning children between 4 and 5 years of age with a so far unobserved u-shaped developmental pattern. In the elicited imitation task, all groups showed a strong tendency to maintain the structure of in-situ and ex-situ questions in repeating grammatical questions. When repairing ungrammatical ex-situ questions, structural changes to grammatical in-situ questions were hardly observed but the insertion of missing morphemes while keeping the ex-situ structure. Together, our findings provide only partial support for the Derivational Complexity Hypothesis.
Macrophages have important protective functions during infection with herpes simplex virus type 1 (HSV-1). However, molecular mechanisms that restrict viral propagation and protect from severe disease are unclear. Here we show that macrophages take up HSV-1 via endocytosis and transport the virions into multivesicular bodies (MVBs). In MVBs, acid ceramidase (aCDase) converts ceramide into sphingosine and increases the formation of sphingosine-rich intraluminal vesicles (ILVs). Once HSV-1 particles reach MVBs, sphingosine-rich ILVs bind to HSV-1 particles, which restricts fusion with the limiting endosomal membrane and prevents cellular infection. Lack of aCDase in macrophage cultures or in Asah1(-/-) mice results in replication of HSV-1 and Asah1(-/-) mice die soon after systemic or intravaginal inoculation. The treatment of macrophages with sphingosine enhancing compounds blocks HSV-1 propagation, suggesting a therapeutic potential of this pathway. In conclusion, aCDase loads ILVs with sphingosine, which prevents HSV-1 capsids from penetrating into the cytosol.
The application of inhomogeneous AC electric fields for molecular immobilization is a very fast and simple method that does not require any adaptions to the molecule's functional groups or charges. Here, the method is applied to a completely new category of molecules: small organic fluorescence dyes, whose dimensions amount to only 1 nm or even less. The presented setup and the electric field parameters used allow immobilization of dye molecules on the whole electrode surface as opposed to pure dielectrophoretic applications, where molecules are attracted only to regions of high electric field gradients, i.e., to the electrode tips and edges. In addition to dielectrophoresis and AC electrokinetic flow, molecular scale interactions and electrophoresis at short time scales are discussed as further mechanisms leading to migration and immobilization of the molecules.
For hybrid organic-inorganic as well as all-inorganic lead halide perovskites a Rashba effect has been invoked to explain the high efficiency in energy conversion by prohibiting direct recombination. Both a bulk and surface Rashba effect have been predicted. In the valence band of methylammonium (MA) lead bromide a Rashba effect has been reported by angle-resolved photoemission and circular dichroism with giant values of 7-11 eV angstrom. We present band dispersion measurements of MAPbBr(3) and spin-resolved photoemission of CsPbBr3 to show that a large Rashba effect detectable by photoemission or circular dichroism does not exist and cannot be the origin of the high effciency.
ABCB1/4 gallbladder cancer risk variants identified in India also show strong effects in Chileans
(2020)
Background: The first large-scale genome-wide association study of gallbladder cancer (GBC) recently identified and validated three susceptibility variants in the ABCB1 and ABCB4 genes for individuals of Indian descent. We investigated whether these variants were also associated with GBC risk in Chileans, who show the highest incidence of GBC worldwide, and in Europeans with a low GBC incidence.
Methods: This population-based study analysed genotype data from retrospective Chilean case-control (255 cases, 2042 controls) and prospective European cohort (108 cases, 181 controls) samples consistently with the original publication.
Results: Our results confirmed the reported associations for Chileans with similar risk effects. Particularly strong associations (per-allele odds ratios close to 2) were observed for Chileans with high Native American (=Mapuche) ancestry. No associations were noticed for Europeans, but the statistical power was low.
Conclusion: Taking full advantage of genetic and ethnic differences in GBC risk may improve the efficiency of current prevention programs.
We analyze the spatiotemporal evolution of seismicity during a sequence of moderate (an M-w 4.7 foreshock and M-w 5.8 mainshock) earthquakes occurring in September 2019 at the transition between a creeping and a locked segment of the North Anatolian fault in the central Sea of Marmara, northwest Turkey. To investigate in detail the seismicity evolution, we apply a matched-filter technique to continuous waveforms, thus reducing the magnitude threshold for detection. Sequences of foreshocks preceding the two largest events are clearly seen, exhibiting two different behaviors: a long-term activation of the seismicity along the entire fault segment and a short-term concentration around the epicenters of the large events. We suggest a two-scale preparation phase, with aseismic slip preparing the mainshock final rupture a few days before, and a cascade mechanism leading to the nucleation of the mainshock. Thus, our study shows a combination of seismic and aseismic slip during the foreshock sequence changing the strength of the fault, bringing it closer to failure.
Schema modes (ormodes) are a key concept in the theory underlying schema therapy. Modes have rarely been related to established models of personality traits. The present study thus investigates the associations between trait emotional intelligence (TEI) and 14 modes, and tests a global TEI-mode factors-general psychological distress mediation model. The study draws on self-report data from 173 inpatients from a German clinic for psychosomatic medicine. Global TEI correlated positively with both healthy modes (happy child and healthy adult) and negatively with 10 maladaptive modes. When modes were regressed on the four TEI factors, six (emotionality), five (well-being), four (sociability), and four (self-control) significant partial effects on 10 modes emerged. In the parallel mediation model, the mode factors internalization and compulsivity fully mediated the global TEI-general psychological distress link. Implications of the results for the integration of modes with traits in general and with TEI in particular as well as implications of low TEI as a transdiagnostic feature of personality malfunctioning are discussed.
A treemap is a visualization that has been specifically designed to facilitate the exploration of tree-structured data and, more general, hierarchically structured data. The family of visualization techniques that use a visual metaphor for parent-child relationships based “on the property of containment” (Johnson, 1993) is commonly referred to as treemaps. However, as the number of variations of treemaps grows, it becomes increasingly important to distinguish clearly between techniques and their specific characteristics. This paper proposes to discern between Space-filling Treemap TS, Containment Treemap TC, Implicit Edge Representation Tree TIE, and Mapped Tree TMT for classification of hierarchy visualization techniques and highlights their respective properties. This taxonomy is created as a hyponymy, i.e., its classes have an is-a relationship to one another: TS TC TIE TMT. With this proposal, we intend to stimulate a discussion on a more unambiguous classification of treemaps and, furthermore, broaden what is understood by the concept of treemap itself.
Pollen records from Siberia are mostly absent in global or Northern Hemisphere synthesis works. Here we present a taxonomically harmonized and temporally standardized pollen dataset that was synthesized using 173 palynological records from Siberia and adjacent areas (northeastern Asia, 42-75 degrees N, 50-180 degrees E). Pollen data were taxonomically harmonized, i.e. the original 437 taxa were assigned to 106 combined pollen taxa. Age-depth models for all records were revised by applying a constant Bayesian age-depth modelling routine. The pollen dataset is available as count data and percentage data in a table format (taxa vs. samples), with age information for each sample. The dataset has relatively few sites covering the last glacial period between 40 and 11.5 ka (calibrated thousands of years before 1950 CE) particularly from the central and western part of the study area. In the Holocene period, the dataset has many sites from most of the area, with the exception of the central part of Siberia. Of the 173 pollen records, 81 % of pollen counts were downloaded from open databases (GPD, EPD, PANGAEA) and 10 % were contributions by the original data gatherers, while a few were digitized from publications. Most of the pollen records originate from peatlands (48 %) and lake sediments (33 %). Most of the records (83 %) have >= 3 dates, allowing the establishment of reliable chronologies. The dataset can be used for various purposes, including pollen data mapping (example maps for Larix at selected time slices are shown) as well as quantitative climate and vegetation reconstructions. The datasets for pollen counts and pollen percentages are available at https://doi.org/10.1594/PANGAEA.898616 (Cao et al., 2019a), also including the site information, data source, original publication, dating data, and the plant functional type for each pollen taxa.
Most South Asian countries have challenges in ensuring water, energy, and food (WEF) security, which are often interacting positively or negatively. To address these challenges, the nexus approach provides a framework to identify the interactions of the WEF sectors as an integrated system. However, most nexus studies only qualitatively discuss the interactions between these sectors. This study conducts a systematic analysis of the WEF security nexus in South Asia by using open data sources at the country scale. We analyze interactions between the WEF sectors statistically, defining positive and negative correlations between the WEF security indicators as synergies and trade-offs, respectively. By creating networks of the synergies and trade-offs, we further identify most positively and negatively influencing indicators in the WEF security nexus. We observe a larger share of trade-offs than synergies within the water and energy sectors and a larger share of synergies than trade-offs among the WEF sectors for South Asia. However, these observations vary across the South Asian countries. Our analysis highlights that strategies on promoting sustainable energy and discouraging fossil fuel use could have overall positive effects on the WEF security nexus in the countries. This study provides evidence for considering the WEF security nexus as an integrated system rather than just a combination of three different sectors or securities.
Context
The recently claimed discovery of a massive (M-BH = 68(-13)(+11) M-circle dot) black hole in the Galactic solar neighborhood has led to controversial discussions because it severely challenges our current view of stellar evolution.
Aims
A crucial aspect for the determination of the mass of the unseen black hole is the precise nature of its visible companion, the B-type star LSV +22 25. Because stars of different mass can exhibit B-type spectra during the course of their evolution, it is essential to obtain a comprehensive picture of the star to unravel its nature and, thus, its mass.
Methods
To this end, we study the spectral energy distribution of LSV +22 25 and perform a quantitative spectroscopic analysis that includes the determination of chemical abundances for He, C, N, O, Ne, Mg, Al, Si, S, Ar, and Fe.
Results
Our analysis clearly shows that LSV +22 25 is not an ordinary main sequence B-type star. The derived abundance pattern exhibits heavy imprints of the CNO bi-cycle of hydrogen burning, that is, He and N are strongly enriched at the expense of C and O. Moreover, the elements Mg, Al, Si, S, Ar, and Fe are systematically underabundant when compared to normal main-sequence B-type stars. We suggest that LSV +22 25 is a stripped helium star and discuss two possible formation scenarios. Combining our photometric and spectroscopic results with the Gaia parallax, we infer a stellar mass of 1.1 +/- 0.5 M-circle dot. Based on the binary system's mass function, this yields a minimum mass of 2-3 M-circle dot for the compact companion, which implies that it may not necessarily be a black hole but a massive neutron- or main sequence star.
Conclusions
The star LSV +22 25 has become famous for possibly having a very massive black hole companion. However, a closer look reveals that the star itself is a very intriguing object. Further investigations are necessary for complete characterization of this object.
Other than commonly assumed in seismology, the phase velocity of Rayleigh waves is not necessarily a single-valued function of frequency. In fact, a single Rayleigh mode can exist with three different values of phase velocity at one frequency. We demonstrate this for the first higher mode on a realistic shallow seismic structure of a homogeneous layer of unconsolidated sediments on top of a half-space of solid rock (LOH). In the case of LOH a significant contrast to the half-space is required to produce the phenomenon. In a simpler structure of a homogeneous layer with fixed (rigid) bottom (LFB) the phenomenon exists for values of Poisson's ratio between 0.19 and 0.5 and is most pronounced for P-wave velocity being three times S-wave velocity (Poisson's ratio of 0.4375). A pavement-like structure (PAV) of two layers on top of a half-space produces the multivaluedness for the fundamental mode. Programs for the computation of synthetic dispersion curves are prone to trouble in such cases. Many of them use mode-follower algorithms which loose track of the dispersion curve and miss the multivalued section. We show results for well established programs. Their inability to properly handle these cases might be one reason why the phenomenon of multivaluedness went unnoticed in seismological Rayleigh wave research for so long. For the very same reason methods of dispersion analysis must fail if they imply wave number k(l)(omega) for the lth Rayleigh mode to be a single-valued function of frequency.. This applies in particular to deconvolution methods like phase-matched filters. We demonstrate that a slant-stack analysis fails in the multivalued section, while a Fourier-Bessel transformation captures the complete Rayleigh-wave signal. Waves of finite bandwidth in the multivalued section propagate with positive group-velocity and negative phase-velocity. Their eigenfunctions appear conventional and contain no conspicuous feature.
A shelter for the future
(2020)
Plant development in its majority occurs post-embryonically
through the activity of local meristems that provide daughter cells
for the development of new organs. It has long been acknowledged
that the shoot apical meristem (SAM), which holds the stem cells
that will form above-ground organs, is recalcitrant to infection by
multiple pathogens, a crucial strategy to safeguard normal devel-
opment and subsequent generations. However, the molecular
mechanisms underlying SAM immunity remain largely unknown.
This paper analyzes a specific section of Martial’s Apophoreta (Book 14), the ‘list’ of fourteen literary works that the poet-persona suggests to the reader as potentially suitable presents to give to friends on the occasion of the Saturnalia. It focuses strictly on the literary aspects of the poems and their underlying carnivalesque poetics. This includes an assessment of the logic of the poems’ arrangement and alleged inconsistencies. It is suggested that the section be read as a complex statement of Martial’s on various works and genres of Greek and Roman literature. The last couplet of the section (14.196), a certain Calvus’ work ‘On the use of cold water’ (De aquae frigidae usu), which is unidentifiable, receives particular attention, for previous scholarship has wasted a lot of ink on guessing what kind of work this may have been, thereby losing touch with the rich (meta-)poetics the couplet actually conveys.
The study of the Cauchy problem for solutions of the heat equation in a cylindrical domain with data on the lateral surface by the Fourier method raises the problem of calculating the inverse Laplace transform of the entire function cos root z. This problem has no solution in the standard theory of the Laplace transform. We give an explicit formula for the inverse Laplace transform of cos root z using the theory of analytic functionals. This solution suits well to efficiently develop the regularization of solutions to Cauchy problems for parabolic equations with data on noncharacteristic surfaces.
We study the source properties of the 2005 Kashmir earthquake and its aftershocks to unravel the seismotectonics of the NW Himalayan syntaxis. The mainshock and larger aftershocks have been simultaneously relocated using phase data. We use back-projection of high-frequency energy from multiple teleseismic arrays to model the spatio-temporal evolution of the mainshock rupture. Our analysis reveal a bilateral rupture, which initially propagated SE and then NW of the epicenter, with an average rupture velocity of similar to 2 km s(-1). The area of maximum energy release is parallel to and bound by the surface rupture. Incorporating rupture propagation and velocity, we model the mainshock as a line source using P- and SH-waveform inversion. Our result confirms that the mainshock occurred on a NE dipping (similar to 35 degrees) fault plane, with centroid depth of similar to 10 km. Integrated source time function show that majority of the energy was released in the first similar to 20 s, and was confined above the hypocenter. From waveform inverted fault dimension and seismic moment, we argue that the mainshock had an additional similar to 25 km blind rupture beyond the NW Himalayan syntaxis. Combining this with findings from previous studies, we conjecture that the blind rupture propagated NW of the syntaxis underneath a weak detachment overlain by infra-Cambrian salt layer, and terminated in a wedge thrust. All moderate-to-large aftershocks, NW of the mainshock rupture, are concentrated at the edge of the blind rupture termination. Source modeling of these aftershocks reveal thrust mechanism with centroid depths of 2-10 km, and fault planes oriented subparallel to the mainshock rupture. To study the influence of mainshock rupture on aftershock occurrence, we compute Coulomb failure stress on aftershock faults. All these aftershocks lie in the positive Coulomb stress change region. This suggest that the aftershocks have been triggered by either co-seismic or post-seismic slip on the mainshock fault.
Subdwarf B stars are core-helium-burning stars located on the extreme horizontal branch (EHB). Extensive mass loss on the red giant branch is necessary to form them. It has been proposed that substellar companions could lead to the required mass loss when they are engulfed in the envelope of the red giant star. J08205+0008 was the first example of a hot subdwarf star with a close, substellar companion candidate to be found. Here, we perform an in-depth re-analysis of this important system with much higher quality data allowing additional analysis methods. From the higher resolution spectra obtained with ESO-VLT/XSHOOTER, we derive the chemical abundances of the hot subdwarf as well as its rotational velocity. Using the Gaia parallax and a fit to the spectral energy distribution in the secondary eclipse, tight constraints to the radius of the hot subdwarf are derived. From a long-term photometric campaign, we detected a significant period decrease of -3.2(8) x 10(-12) dd(-1). This can be explained by the non-synchronized hot subdwarf star being spun up by tidal interactions forcing it to become synchronized. From the rate of period decrease we could derive the synchronization time-scale to be 4 Myr, much smaller than the lifetime on EHB. By combining all different methods, we could constrain the hot subdwarf to a mass of 0.39-0.50 M-circle dot and a radius of R-sdB = 0.194 +/- 0.008 R-circle dot, and the companion to 0.061-0.071 M-circle dot with a radius of R-comp = 0.092 +/- 0.005 R-circle dot, below the hydrogen-burning limit. We therefore confirm that the companion is most likely a massive brown dwarf.