julilili42/papers huggingface dataset:
Magnitude Codes for Cross-Modal Working Memory in the Primate Frontal Association Cortex
2017-04-07

Quantitative features of stimuli may be ordered along a magnitude continuum, or line. Magnitude refers to parameters of different types of stimulus properties. For instance, the frequency of a sound relates to sensory and continuous stimulus properties, whereas the number of items in a set is an abstract and discrete property. In addition, within a stimulus property, magnitudes need to be processed not only in one modality, but across multiple modalities. In the sensory domain, for example, magnitude applies to both to the frequency of auditory sounds and tactile vibrations. Similarly, both the number of visual items and acoustic events constitute numerical quantity, or numerosity. To support goal-directed behavior and executive functions across time, magnitudes need to be held in working memory, the ability to briefly retain and manipulate information in mind. How different types of magnitudes across multiple modalities are represented in working memory by single neurons has only recently been explored in primates. These studies show that neurons in the frontal lobe can encode the same magnitude type across sensory modalities. However, while multimodal sensory magnitude in relative comparison tasks is represented by monotonically increasing or decreasing response functions ("summation code"), multimodal numerical quantity in absolute matching tasks is encoded by neurons tuned to preferred numerosities ("labeled-line code"). These findings indicate that most likely there is not a single type of cross-modal working-memory code for magnitudes, but rather a flexible code that depends on the stimulus dimension as well as on the task requirements.
Alteration of high-density lipoprotein functionality in Alzheimer’s disease patients
2017-04-07

The aims of the present study were to determine whether high-density lipoprotein (HDL) functionality-mediated cholesterol efflux is altered in Alzheimer’s disease and to investigate the role and effect of amyloid-beta (Aβ) in the regulation of the anti-atherogenic activity of HDL. Eighty-seven elderly subjects were recruited, of whom 27 were healthy, 27 had mild cognitive impairment (MCI), and 33 had mild Alzheimer’s disease (mAD). Our results showed that total cholesterol levels are negatively correlated with the Mini-Mental State Examination (MMSE) score (r = –0.2602, p = 0.0182). HDL from the mAD patients was less efficient at mediating cholesterol efflux from J774 macrophages (p &lt; 0.05) than HDL from the healthy subjects and MCI patients. While HDL from the MCI patients was also less efficient at mediating cholesterol efflux than HDL from the healthy subjects, the difference was not significant. Interestingly, the difference between the healthy subjects and the MCI and mAD patients with respect to the capacity of HDL to mediate cholesterol efflux disappeared when ATP-binding cassette transporter A1 (ABCA1)-enriched J774 macrophages were used. HDL fluidity was significantly inversely correlated with the MMSE scores (r = –0.4137, p &lt; 0.009). In vitro measurements of cholesterol efflux using J774 macrophages showed that neither Aβ 1-40 nor Aβ 1-42 stimulate cholesterol efflux from unenriched J774 macrophages in basal or ABCA1-enriched J774 macrophages.
Detecting high spatial variability of ice-shelf basal mass balance(Roi Baudouin ice shelf, Antarctica)
2017-04-07

Abstract. Ice shelves control the dynamic mass loss of ice sheets through buttressing and their integrity depends on the spatial variability of their basal mass balance (BMB), i.e., the difference between refreezing and melting. Here, we present a novel technique – based on satellite observations – to capture the small-scale variability in the BMB of ice-shelves. As a case study we apply the methodology to the Roi Baudouin Ice Shelf, Dronning Maud Land, East Antarctica and derive its yearly-averaged BMB at 10 m horizontal gridding. We use mass conservation within a Lagrangian framework based on high-resolution surface velocities, atmospheric-model surface mass balance and hydrostatic ice-thickness fields (derived from TanDEM-X surface elevation). Spatial derivatives are implemented using the total-variation differentiation, which avoids spatial averaging hence loss of spatial resolution. Our BMB field exhibits high detail and ranges from −14.8 to 8.6 m a−1 ice equivalent. Highest melt rates are found close to the grounding line where the basal ice-shelf slope is the steepest. The BMB field agrees well with on-site measurements from phase-sensitive radar, although unresolved spatial variations in firn density determined from profiling radar occur. We show that the surface expression of an englacial lake (0.7 × 1.3 km2 wide and 30 m deep) lowers by 0.5 to 1.4 m a−1, which we tentatively attribute to a transient adaptation to hydrostatic equilibrium. We find evidence for elevated melting beneath ice-shelf channels (with melting being concentrated on the channel's flanks). However, farther downstream from the grounding line, the majority of ice-shelf channels advect passively toward the ice-shelf front. Although the absolute, satellite-based BMB values remain uncertain, we have high confidence in the spatial variability on sub-kilometre scales. This study highlights expected challenges for a full coupling between ice and ocean models.
Antibiotic resistance: What is so special about multidrug-resistant Gram-negative bacteria?
2017-04-10

In the past years infections caused by multidrug-resistant Gram-negative bacteria have dramatically increased in all parts of the world. This consensus paper is based on presentations, subsequent discussions and an appraisal of current literature by a panel of international experts invited by the Rudolf Schülke Stiftung, Hamburg. It deals with the epidemiology and the inherent properties of Gram-negative bacteria, elucidating the patterns of the spread of antibiotic resistance, highlighting reservoirs as well as transmission pathways and risk factors for infection, mortality, treatment and prevention options as well as the consequences of their prevalence in livestock. Following a global, One Health approach and based on the evaluation of the existing knowledge about these pathogens, this paper gives recommendations for prevention and infection control measures as well as proposals for various target groups to tackle the threats posed by Gram-negative bacteria and prevent the spread and emergence of new antibiotic resistances.
Testing strong-field gravity with tidal Love numbers
2017-04-10

The tidal Love numbers (TLNs) encode the deformability of a self-gravitating object immersed in a tidal environment and depend significantly both on the object's internal structure and on the dynamics of the gravitational field. An intriguing result in classical general relativity is the vanishing of the TLNs of black holes. We extend this result in three ways, aiming at testing the nature of compact objects: (i) we compute the TLNs of exotic compact objects, including different families of boson stars, gravastars, wormholes, and other toy models for quantum corrections at the horizon scale. In the black-hole limit, we find a universal logarithmic dependence of the TLNs on the location of the surface. (ii) We compute the TLNs of black holes beyond vacuum general relativity, including Einstein-Maxwell, Brans-Dicke, and Chern-Simons gravity. (iii) We assess the ability of present and future gravitational-wave detectors to measure the TLNs of these objects, including the first analysis of TLNs with LISA. Both LIGO, ET, and LISA can impose interesting constraints on boson stars, while LISA is able to probe even extremely compact objects. We argue that the TLNs provide a smoking gun of new physics at the horizon scale and that future gravitational-wave measurements of the TLNs in a binary inspiral provide a novel way to test black holes and general relativity in the strong-field regime.
Words from spontaneous conversational speech can be recognized with human-like accuracy by an error-driven learning algorithm that discriminates between meanings straight from smart acoustic features, bypassing the phoneme as recognition unit
2017-04-10

Sound units play a pivotal role in cognitive models of auditory comprehension. The general consensus is that during perception listeners break down speech into auditory words and subsequently phones. Indeed, cognitive speech recognition is typically taken to be computationally intractable without phones. Here we present a computational model trained on 20 hours of conversational speech that recognizes word meanings within the range of human performance (model 25%, native speakers 20-44%), without making use of phone or word form representations. Our model also generates successfully predictions about the speed and accuracy of human auditory comprehension. At the heart of the model is a 'wide' yet sparse two-layer artificial neural network with some hundred thousand input units representing summaries of changes in acoustic frequency bands, and proxies for lexical meanings as output units. We believe that our model holds promise for resolving longstanding theoretical problems surrounding the notion of the phone in linguistic theory.
Increased Diagnostic Accuracy of Digital vs. Conventional Clock Drawing Test for Discrimination of Patients in the Early Course of Alzheimer’s Disease from Cognitively Healthy Individuals
2017-04-10

The conventional Clock Drawing Test (cCDT) is a rapid and inexpensive screening tool for detection of moderate and severe dementia. However, its usage is limited due to poor diagnostic accuracy especially in patients with mild cognitive impairment (MCI). The diagnostic value of a newly developed digital Clock Drawing Test (dCDT) was evaluated and compared with the cCDT in 20 patients with early dementia due to AD (eDAT), 30 patients with amnestic MCI (aMCI) and 20 cognitively healthy controls (HCs). Parameters assessed by dCDT were time while transitioning the stylus from one stroke to the next above the surface (i.e., time-in-air), time the stylus produced a visible stroke (i.e., time-on-surface) and total-time during clock drawing. Receiver-operating characteristic (ROC) curves were calculated and logistic regression analyses have been conducted for statistical analysis. Using dCDT, time-in-air was significantly increased in eDAT (70965.8 ms) compared to aMCI (54073.7 ms; <i>p</i> = 0.027) and HC (32315.6 ms; <i>p</i> < 0.001). In addition, time-in-air was significantly longer in patients with aMCI compared to HC (<i>p</i> = 0.003), even in the aMCI group with normal cCDT score (54141.8 ms; <i>p</i> < 0.001). Time-in-air using dCDT allowed discrimination of patients with aMCI from HCs with a sensitivity of 81.3% and a specificity of 72.2% while cCDT scoring revealed a sensitivity of 62.5% and a specificity of 83.3%. Most interestingly, time-in-air allowed even discrimination of aMCI patients with normal cCDT scores (80% from all aMCI patients) from HCs with a clinically relevant sensitivity of 80.8% and a specificity of 77.8%. A combination of dCDT variables and cCDT scores did not improve the discrimination of patients with aMCI from HC. In conclusion, assessment of time-in-air using dCDT yielded a higher diagnostic accuracy for discrimination of aMCI patients from HCs than the use of cCDT even in those aMCI patients with normal cCDT scores. Modern digitizing devices offer the opportunity to measure subtle changes of visuo-constructive demands and executive functions that may be used as a fast and easy to perform screening instrument for the early detection of cognitive impairment in primary care.
Identification of a cono-RFamide from the venom of Conus textile that targets ASIC3 and enhances muscle pain
2017-04-10

Significance Marine cone snails provide one of the highest toxin diversities among venomous animals, the conotoxins, which often target ion channels. In addition, cone snail venoms contain short conopeptides, the molecular targets of which are mostly unknown. We identified a new conopeptide from the venom of the cone snail Conus textile that targets the proton-gated ion channel ASIC3, which detects painful acidosis. This peptide belongs to the subgroup of cono-RFamides and potentiates ASIC3 currents, thereby increasing the excitability of nociceptors. Injection of the cono-RFamide in mice muscle enhanced acid-induced muscle pain. Our results thus identify ASIC3 as the first molecular target of cono-RFamides. These findings underline the role of ASIC3 in pain perception and the importance of nontoxic venom components.
A Revised Iron Extraction Protocol for Environmental Samples Rich in Nitrite and Carbonate
2017-04-10

Wet-chemical iron extraction is widely applied to quantify the mineral-bound ferriferous fraction of sediments and soils. As previously shown, this method is strongly affected by the composition of the soil/sediment. Samples enriched in mostly microbially produced nitrite require the removal of the nitrite-containing aqueous phase or the replacement of HCl with sulfamic acid (SA) as the extractant. In this study, we show that sedimentary carbonate buffers SA, inhibiting the stabilization of Fe(II) and effective extraction of iron. We therefore provide a revised extraction protocol which allows the preservation of low pH conditions, leading to efficient iron extraction in nitrite-and carbonate-enriched samples.
Algorithm for Turning Detection and Analysis Validated under Home-Like Conditions in Patients with Parkinson’s Disease and Older Adults using a 6 Degree-of-Freedom Inertial Measurement Unit at the Lower Back
2017-04-10

This wearable sensor- and relative orientation-based algorithm yields very high agreement with clinical observation for the detection and evaluation of ≥90° turns under non-standardized conditions in PD patients and older adults. It can be suggested for the assessment of turning in daily life.
Homoepitaxy of Crystalline Rubrene Thin Films
2017-04-10

The smooth surface of crystalline rubrene films formed through an abrupt heating process provides a valuable platform to study organic homoepitaxy. By varying growth rate and substrate temperature, we are able to manipulate the onset of a transition from layer-by-layer to island growth modes, while the crystalline thin films maintain a remarkably smooth surface (less than 2.3 nm root-mean-square roughness) even with thick (80 nm) adlayers. We also uncover evidence of point and line defect formation in these films, indicating that homoepitaxy under our conditions is not at equilibrium or strain-free. Point defects that are resolved as screw dislocations can be eliminated under closer-to-equilibrium conditions, whereas we are not able to eliminate the formation of line defects within our experimental constraints at adlayer thicknesses above ∼25 nm. We are, however, able to eliminate these line defects by growing on a bulk single crystal of rubrene, indicating that the line defects are a result of strain built into the thin film template. We utilize electron backscatter diffraction, which is a first for organics, to investigate the origin of these line defects and find that they preferentially occur parallel to the (002) plane, which is in agreement with expectations based on calculated surface energies of various rubrene crystal facets. By combining the benefits of crystallinity, low surface roughness, and thickness-tunability, this system provides an important study of attributes valuable to high-performance organic electronic devices.
Composing wie wenn—the semantics of hypothetical comparison clauses in German
2017-04-10

This paper addresses the compositional semantics of hypothetical comparison clauses (= HCCs) in German. HCCs are introduced by either wie ('how') or als ('as'); for example, Ben fährt Rad, {wie wenn er betrunken wäre / als wenn er betrunken wäre / als ob er betrunken wäre / als wäre er betrunken} ('Ben is cycling as if he were drunk'). I argue for the following hypotheses: (i) Based on an explicit conditional antecedent, HCCs license the interpolation of hypothetical scenarios that give rise to an equivalence relation between entities provided by these scenarios and the given explicit matrix information. (ii) The equivalence relation may hold either between particularized properties (e.g., manners) of hypothetical events and the given matrix event (= V-HCCs), or between hypothetical topic situations and the matrix situation against which the given matrix clause as a whole is evaluated (= S-HCCs). The proposed semantic distinction is traced back to a structural contrast and, thus, is compositionally motivated: V-HCCs relate to the verbal head of the matrix clause, while S-HCCs are non-integrated CP-adjuncts. (iii) Both wie and als lexically encode the relevant mediating equivalence relation; while HCCs with wie allow a regular compositional interpretation in terms of by and large ordinary free relative clauses, als projects rather idiosyncratic semantic (and syntactic) properties.
Crystal Structure and Luminescence Investigations of the Nitridomagnesoaluminates Mg3AlnNn+2 with n = 1, 2, 3
2017-04-10

Mg 3 Al 3 N 5 , Mg 3 Al 2 N 4 , and Mg 3 AlN 3 were synthesized at 1100 °C in a closed system by utilizing weld‐shut niobium ampoules. Their crystal structures were solved and refined on the basis of powder XRD data in space group P 6 3 / mmc [ a = b = 3.2422(1), c = 26.340(1) Å, Z = 2] for Mg 3 Al 3 N 5 , P 3 m 1 [ a = b = 3.2860(1), c = 10.7461(1) Å, Z = 1] for Mg 3 Al 2 N 4 , and R 3 m [ a = b = 3.3683(0), c = 25.4835(1) Å, Z = 3] for Mg 3 AlN 3 . Their crystal structures are characterized by wurtzite‐type [AlN] and [MgN] block layers alternating with octahedral [MgN] layers along the c ‐axis direction. Europium(III)‐doped samples of Mg 3 Al 3 N 5 show characteristic emission in the visible region of the spectrum on excitation with UV radiation at λ ex = 370 nm. Mg 3 AlN 3 doped with europium(II) shows yellow luminescence on excitation with UV radiation at λ ex = 365 nm.
Anterior cingulate cortex represents action-state predictions and causally mediates model-based reinforcement learning in a two-step decision task
2017-04-11

Summary The anterior cingulate cortex (ACC) is implicated in learning the value of actions, but it remains poorly understood whether and how it contributes to model-based mechanisms that use action-state predictions and afford behavioural flexibility. To isolate these mechanisms, we developed a multi-step decision task for mice in which both action-state transition probabilities and reward probabilities changed over time. Calcium imaging revealed ramps of choice-selective neuronal activity, followed by an evolving representation of the state reached and trial outcome, with different neuronal populations representing reward in different states. ACC neurons represented the current action-state transition structure, whether state transitions were expected or surprising, and the predicted state given chosen action. Optogenetic inhibition of ACC blocked the influence of action-state transitions on subsequent choice, without affecting the influence of rewards. These data support a role for ACC in model-based reinforcement learning, specifically in using action-state transitions to guide subsequent choice. Highlights A novel two-step task disambiguates model-based and model-free RL in mice. ACC represents all trial events, reward representation is contextualised by state. ACC represents action-state transition structure, predicted states, and surprise. Inhibiting ACC impedes action-state transitions from influencing subsequent choice.
Optimized Target Residence Time: Type I Inhibitors for p38α MAP Kinase with Improved Binding Kinetics through Direct Interaction with the R‐Spine
2017-04-11

Abstract Skepinone‐L was recently reported to be a p38α MAP kinase inhibitor with high potency and excellent selectivity in vitro and in vivo. However, this class of compounds still act as fully ATP‐competitive Type I binders which, furthermore, suffer from short residence times at the enzyme. We herein describe a further development with the first Type I binders for p38α MAP kinase. Type I inhibitors interfere with the R‐spine, inducing a glycine flip and occupying both hydrophobic regions I and II. This design approach leads to prolonged target residence time, binding to both the active and inactive states of the kinase, excellent selectivity, excellent potency on the enzyme level, and low nanomolar activity in a human whole blood assay. This promising binding mode is proven by X‐ray crystallography.
Surface Functionalization with Copper Tetraaminophthalocyanine Enables Efficient Charge Transport in Indium Tin Oxide Nanocrystal Thin Films
2017-04-11

Macroscopic superlattices of tin-doped indium oxide (ITO) nanocrystals (NCs) are prepared by self-assembly at the air/liquid interface followed by simultaneous ligand exchange with the organic semiconductor copper 4,4',4′′,4′′′-tetraaminophthalocyanine (Cu4APc). By using X-ray photoelectron spectroscopy (XPS), grazing-incidence small-angle X-ray scattering (GISAXS), and ultraviolet-visible-near-infrared (UV-vis-NIR) spectroscopy, we demonstrate that the semiconductor molecules largely replace the native surfactant from the ITO NC surface and act as cross-linkers between neighboring particles. Transport measurements reveal an increase in electrical conductance by 9 orders of magnitude, suggesting that Cu4APc provides efficient electronic coupling for neighboring ITO NCs. This material provides the opportunity to study charge and spin transport through phthalocyanine monolayers.
A SAR-Based Index for Landscape Changes in African Savannas
2017-04-11

Change detection is one of the main applications in earth observation but currently there are only a few approaches based on radar imagery. Available techniques strongly focus on optical data. These techniques are often limited to static analyses of image pairs and are frequently lacking results which address the requirements of the user. Some of these shortcomings include integration of user’s expertise, transparency of methods, and communication of results in a comprehensive understandable way. This study introduces an index describing changes in the savanna ecosystem around the refugee camp Djabal, Eastern Chad, based on a time-series of ALOS PALSAR data between 2007 and 2017. Texture based land-use/land cover classifications are transferred to values of natural resources which include comprehensive pertinent expert knowledge about the contributions of the classes to environmental integrity and human security. Changes between the images are analyzed, within grid cells of one kilometer diameter, according to changes of natural resources and the variability of these changes. Our results show the highest resource availability for the year of 2008 but no general decline in natural resources. Largest loss of resources occurred between 2010 and 2011 but regeneration could be observed in the following years. Neither the settlements nor the wadi areas of high ecologic importance underwent significant changes during the last decade.