We investigate the timing of pre-answer inbreaths in order to shed light on the time course of response planning and execution in conversational turn-taking. Using acoustic and inductive plethysmography recordings of seven dyadic conversations in Dutch, we show that pre-answer inbreaths in conversation typically begin briefly after the end of questions. We also show that the presence of a pre-answer inbreath usually co-occurs with substantially delayed answers, with a modal latency of 576 vs. 100 ms for answers not preceded by an inbreath. Based on previously reported minimal latencies for internal intercostal activation and the production of speech sounds, we propose that vocal responses, either in the form of a pre-utterance inbreath or of speech proper when an inbreath is not produced, are typically launched in reaction to information present in the last portion of the interlocutor's turn. We also show that short responses are usually made on residual breath, while longer responses are more often preceded by an inbreath. This relation of inbreaths to answer length suggests that by the time an inbreath is launched, typically during the last few hundred milliseconds of the question, the length of the answer is often prepared to some extent. Together, our findings are consistent with a two-stage model of response planning in conversational turn-taking: early planning of content often carried out in overlap with the incoming turn, and late launching of articulation based on the identification of turn-final cues. Conversation is the core ecological niche for language—it is where language is learnt and most heavily used. Conversation is characterized by the rapid alternation of speakers, who each take mostly small turns at talk, generally avoid vocal overlap, and minimize the gap between turns  whether the characteristics of pre-utterance inbreaths in spontaneous conversation are related to the scope of language planning, (b) whether responses preceded by an inbreath are delayed with respect to end of the interlocutor's turn compared to responses spoken on residual breath, and (c) what the most common timing of pre-utterance inbreaths is relative to the end of the interlocutor's turn. In section Discussion, we review and interpret our findings, and sketch a turn-taking response production mechanism accounting for both the most common trends in the data and previously reported estimates of language processing latencies.The corpus collection procedure and its use for research purposes were approved by the Ethics Committee Faculty of Social Sciences of the Radboud University Nijmegen. The corpus collection took place in a sound-attenuated room at the Max Planck Institute for Psycholinguistics. We recorded seven dyadic conversations between Dutch male friends, all of them university students except one participant (a research assistant). The reason for only recording males is that inductive plethysmography measurements are obtained more reliably from male participants than from female participants. Each recording had a duration of around 45 min, for an approximate total of 6 h and 15 min of dyadic conversation. Participants were briefly instructed to entertain a conversation with their dyad partner while sitting on chairs placed 1.5–2 m from each other, and oriented toward each other at an angle of 120 degrees. Each participant took part in the recordings only once.The recording equipment consisted of a high-definition camera placed in front of the speakers, Shure SM10A head-mounted microphones, and an InductotraceTM inductive plethysmography system. Each participant wore an Inductotrace band attached around his chest at the level of the axilla, each connected to one of the two channels of the Inductotrace unit, and a head mounted-microphone coupled to an amplifier. The speech and breathing signals were recorded simultaneously at a sampling frequency of 48 kHz via an A/D converter connected to a computer. The breathing signals exhibited an upward drift starting approximately 10 min into the recording. Such a drift has not been reported in previous studies using the Inductotrace system, perhaps because their recordings were much shorter than ours. In order to correct this drift, we approximated the signals with third-order polynomials using the polyfit Matlab function, and extracted their residuals. Finally, we smoothed the signals by downsampling them by a factor of 1000.n = 171). Each dyad contributed between 15 and 30 question-answer sequences (mean = 21.6) to the dataset. Each speaker contributed between 4 and 26 answers to the dataset . The first author then marked the beginning and end of each question and answer. At the phonetic level, the beginning and end of answers and questions were located with reference to acoustic events in the signal attributable to either a lexical item or a particle . Mouth noises, clicks and breathing noises were therefore not treated as part of the questions and answers. The beginning of the question was located with reference to syntactic structure . The end of the answer was placed at the first pause that coincided with points of completion both at the syntactic and intonational levels. All answers therefore consisted of at least one syntactically and intonationally coherent phrase. We also coded the preference status of all answers in our data. We coded as preferred responses all responses to polar questions that matched them in polarity , and answers to wh-questions that provided the requested information. Dispreferred responses included all other types of responses .Using Elan software , since inbreaths that started before the question could not have been produced in response to it. The shape of answerers' breathing signals in the considered interval showed considerable variation, and, in this respect, contrast with the breathing patterns described in studies based on highly-controlled speech. The signals could be flat with a final inbreath, but also falling or rising , or exhibit a mixture of the preceding types . Moreover, it is probable that a number of the inbreaths that fell in the considered time interval were not primarily designed for speech. They could instead have been part of initially vital or partly vital breathing cycles that happened to occur in overlap with the question and preceding the answer. Although prototypical vital and speech breathing cycles differ very clearly under highly-controlled conditions  only if they started after the beginning of the question and before the answer . Since the amplitude values in our data are approximately normally distributed, the normalized amplitude range for each speaker should roughly extend from −2 to 2 (excluding outliers). Figure The onset and offset of each annotated inbreath was marked at the signal minimum and maximum by an assistant unaware of the purpose of the study. In some cases where there was a low plateau, the onset was located at the “elbow” located at the end of the plateau rather than at the absolute minimum. We also measured the amplitude of each inbreath, and later converted this measure to speaker-normalized In order to investigate statistical relationships between variables of interest, we fit mixed-effects regression models using the lme4 R package :Are the characteristics of pre-utterance inbreaths related to the scope of language planning? .Are responses preceded by an inbreath delayed with respect to end of the interlocutor's turn compared to responses spoken on residual breath? (Section Pre-utterance Inbreaths and Answer Latency).What is the most common timing of pre-utterance inbreaths relative to the end of the interlocutor's turn? (Section Timing of Answerer's Inbreaths Relative to Question Ends).p = 0.52), and was therefore dropped from subsequent analyses. On the other hand, the presence of disfluencies in the answer provided a highly statistically significant improvement over the null model , indicating that pre-utterance inbreaths are more likely before answers containing one or more hesitations. Interestingly, a model including the presence of disfluencies in the answer plus answer duration compared favorably to a model including the presence of disfluencies only , and indicated that pre-utterance inbreaths are more likely the longer the answer . This is illustrated in Figure z = 1.78, p = 0.07), perhaps due to the fact that this variable and answer duration, the other fixed predictor, were moderately correlated (r = 0.59). In the same way, adding the presence of disfluencies in the answer to a model with answer duration as the only fixed predictor did not result into a statistical improvement . Thus, the relationship between answer duration and pre-utterance inbreaths cannot be explained away by the correlation between answer duration and the presence of disfluencies in the answer. Instead, it appears that answer duration is a better predictor of whether a pre-utterance inbreath is present than the fluency of the answer.As mentioned above, only 53.2% of the answers to questions were preceded by an inbreath. We first examined whether the presence or absence of pre-utterance inbreaths is related to the duration of the answer. Because pre-utterance inbreaths could also be affected by the preference status of the answer, and by the presence of disfluencies in the answer, we first fit two reduced logistic mixed-effects regression models with either of these two variables as fixed predictors, speaker as a random factor, and the presence of a pre-utterance inbreath as the response. The preference status of the answer did not significantly improve the fit of a null model . Adding answer duration to the null models did not improve its fit either for neither of the two response variables . Moreover, visual inspection of the data indicated that this lack of statistical relationships was not due to outliers. Thus, contrary to previous findings  and inbreath duration . We first fitted reduced models with inbreath depth and inbreath duration as responses, and either the preference status of the answer or the presence of disfluencies in the answer as fixed predictors, and observed that none of the fixed predictors was statistically related to any of the two responses (p > 0.05 in both cases). Because longer answers may take longer to plan, we also fitted a reduced model with answer duration as the fixed predictor. In this case, there was a statistical improvement over the null model . Interestingly, adding the occurrence of a pre-utterance inbreath greatly improved the fit of the model . As illustrated in Figure The main question that we wanted to answer in this study concerns whether answerers produce inbreaths in anticipation of question ends in order to produce answers without substantial delays (compared to answers not preceded by a pre-utterance inbreath), or if pre-utterance inbreaths occur close to turn ends, rendering responses later than those without preceding inbreaths. In order to investigate this, we first fitted reduced regression models with answer latency as the response, and either the preference status of the answer or the presence of disfluencies in the answer as a fixed predictor. None of these factors improved the null model . It therefore appears that the clustering of inbreath starts close to question ends is not related to the preference status or the fluency of the response.It is possible that inbreaths that are intended as semiotic signals, for instance announcing an upcoming dispreferred or disfluent answer, may tend to be produced in the clear rather than in overlap with the interlocutor's turn end. To investigate this, we fitted regression models with the distance from inbreath start to question end as the response, and either the preference status of the answer or the presence of disfluencies in the answer as fixed predictors. None of these two predictors provided an improvement over the null model . This suggests that the frequent alignment between answerer inbreaths and question ends observed in our data is unlikely to be random, and that it is likely to be a genuine index of coordination between questioners and answerers.Figure Our findings can be summarized as follows. First, answerers' breathing behavior in question-answer sequences in conversation is related to answer length, and this relationship cannot be explained by either the preference status of the answer or the presence of disfluencies occurring in the answer. Long answers have a greater probability of being preceded by an inbreath than short answers. In contrast, we did not find any relation between answer length and inbreath characteristics such as duration and amplitude, as reported in previous studies , such non-smooth turn transitions require further explanation. Such cases could arise when either early language planning or the launching of articulation based on turn-final cues are not carried out optimally. For instance, one common cause of speech overlap routinely mentioned in the Conversational Analysis literature  early enough to determine whether she needs to take an inbreath before her turn, and launch it in response to the interlocutor's turn-final cues. This may be due to a low attentional level on the part of the speaker, or to the interlocutor's turn being unclear until its very end. In cases in which the speaker is able to complete the initial stages of language production in time to provide a smooth response, but not the later stages , she could still take an early inbreath upon identification of the turn-final cues in the interlocutor's turn, and then use her inbreath, which may stretch for several hundred milliseconds, as a buffer through which to complete the planning of the utterance.We hope to have shown that the study of breathing can shed new and interesting light on the underlying mechanisms involved in turn-taking. The current study is limited to question-answer contexts in which answers are always produced in response to a question. We think that our conclusions regarding the answerer's breathing behavior can be expected to be valid in turn-taking contexts involving readiness to respond on the part of one of the interlocutors. However, further research should explore other conversational contexts in which floor changes may be optional , subject to increased competition for the floor  or involving highly predictable first turns (cf. Magyari and de Ruiter, The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


It is shown that the Sb2Te3 /graphene interface is stable and that coincidence lattices are formed between the epilayers and substrate that depend on the size of the surface unit cell. This demonstrates that there is a significant, although relatively weak, interfacial interaction between the two materials. Lattice matching is thus relevant for vdW epitaxy with two 2D bonded materials and a fundamental design parameter for vdW heterostructures.Van der Waals (vdW) epitaxy is an attractive method for the fabrication of vdW heterostructures. Here Sb The ability to create heterostructures of 2-dimensionally (2D) bonded materials2Te3, a typical 2D bonded material, can form coincidence lattices with reconstructed Si(111) surfacesVdW epitaxy2Te3 thin films were subsequently grown by molecular beam epitaxy (MBE) and characterized by Raman spectroscopy, which showed that the Sb2Te3/graphene interface is stable. Finally, atomic force microscopy (AFM) and x-ray diffraction (XRD) studies on the epilayers reveal two distinct nucleation mechanisms of Sb2Te3 on the graphene. By comparing the in-plane orientation of Sb2Te3 domains grown on graphene with epilayers grown on the buffer layer and on quasi freestanding bilayer graphene the origins of these different nucleation mechanisms are elucidated. Finally, the implications for the synthesis of vdW heterostructures are discussed.Instead of studying vdW epitaxy using passivated substrate surfaces, three types of high quality graphene substratesBefore depositing material on a substrate, it is important to know its topography. Therefore the monolayer epitaxial graphene substrates were studied by tapping-mode AFM. 2Te3 films were deposited on the graphene surfaces by MBE as described in the methods section.The structural properties of the monolayer epitaxial graphene substrates were studied using RHEED. Diffraction pattern taken perpendicular to the SiC < 100 > and < 120 > directions are shown in 2Te3 layers and monolayer epitaxial graphene substrates were studied using Raman spectroscopy. 2Te3 and a region that intentionally was not covered with Sb2Te3 during the deposition. The Raman spectra in the range from 20–200 cm−1 is shown in 2Te3 one can clearly see the presence of the characteristic Raman modes of Sb2Te3, whereas they are absent in the region not covered by Sb2Te3. Note that the sharp lines around 150 cm−1 correspond to the E2 doublet of SiC2Te3 is clearly lower, which is due to the absorption of the light in the Sb2Te3 layer. Nevertheless the spectra are almost identical and the G and 2D peaks, characteristic of graphene, can clearly be observed in both spectra. Furthermore, the defect related peaks, i.e. D, D′ and D + G, are not observed in both spectra. We note that these peaks were also not observed after subtraction of the SiC background signal. This indicates that the graphene structure is unaffected by the deposition of the Sb2Te3 layer and shows that the Sb2Te3/graphene interface is stable. Moreover, the absence of the defect related peaks is a good indication that there is no rehybridization in graphene and thus that there are no covalent bonds formed between graphene and Sb2Te3.The stability of an interface is an important aspect of any epitaxial heterostructure. In order to address this topic, Sb2Te3 films. 2Te3 film with a thickness of 24 nm. It shows that the surface of the 24 nm thick film consists of large flat areas. Those are characterized by terraces separated by 1 nm high steps, as evidenced by the line profile, 2Te3. A more detailed view of the initial growth is obtained by studying surface morphology of an 11 nm thick film, i.e. 2Te3 present in these areas. Furthermore, in 2Te3 layer. It should be pointed out that this particular alignment of the residual part of SiC buffer layer was not observed on all terraces. These observations are therefore consistent with a preferred nucleation of Sb2Te3 on the SiC buffer layer as a cause of the observed ordering.Now we turn to the investigation of the surface topography of the Sbz scan could be indexed as (00n) peaks, indicating that all domains have a (001) out-of-plane orientation. This implies that the domains have a different in-plane orientation. XRD φ-scans on Sb2Te3 (015) and SiC(013) diffraction peak were performed in order to determine the in-plane orientation. The relative orientation of the Sb2Te3 layer with respect to the graphene lattice was determined by considering the 30° rotation of the graphene lattice with respect to the SiC lattices as determined by RHEED, 2Te3 layer grown on graphene consists of domains that are rotated by ±30° with respect to the graphene lattice and of domains that are approximately aligned with the graphene lattice. We note that extended φ-scans showed a 6-fold rotational symmetry, indicating that the film is twinned, as expected from symmetry considerations2Se3 layers grown on graphene182Te3 that are observed are illustrated in the schematics in RHEED patterns taken after the growth see  consiste2Te3 (a = 4.26 Å) was calculated as a function of the rotational angle and the distance between the coincidence lattice points by adapting the approach of Kaneko et al2Te3 lattice is rotated with 30° with respect to graphene. Thus one can expect that this orientation is the most pronounced one, which is consistent with the experimental data. Furthermore, it is observed that a coincidence lattice with the same lattice mismatch can be formed when the rotation between the layers is 2.2° or 8.2°  and Sb2Te3 layers grown on monolayer epitaxial graphene has an orientation that is approximately aligned with the graphene lattice. This suggests that there is another mechanism that influences the in-plane orientation of Sb2Te3. This is consistent with the AFM observations showing that there are two different nucleation densities, and that the growth of Sb2Te3 is affected by the SiC surface regions covered by the (6√3 × 6√3)R30° buffer layer. It is thus important to address the influence of these regions on the epitaxial relationship between Sb2Te3 and graphene. Therefore, additional Sb2Te3 films were grown on SiC substrates mainly covered with the SiC (6√3 × 6√3)R30° buffer layer and on quasi freestanding bilayer graphene substrates. The XRD φ-scan performed on the film grown on the buffer layer substrate, 2Te3 on mono-/bilayer graphene.Besides the orientations that are due to the formation of coincidence lattices, a large part of the Sb2Te3 although a 2D material still can form a coincidence lattice with a reconstructed surface2Te3. The chemical bonding between SiC and the buffer layer results in a (6 × 6) corrugation of the buffer layer. Such a corrugation changes the distance between the carbon and Sb2Te3 layers periodically and hence might influence the interfacial interaction. Therefore, the lattice match of coincidence lattices between Sb2Te3 and the (6 × 6) corrugation were calculated, 2Te3 and the carbon lattice are not rotated with respect for each other. Based on these calculation one thus would expect an alignment of the carbon and Sb2Te3 lattices, which is in full agreement with the experimental results. It is therefore concluded that the epitaxial alignment between Sb2Te3 and the buffer layer is due to the formation of a coincidence lattice between the corrugations of the buffer layer and Sb2Te3.However, it is unclear why the growth on the buffer layer differs so much from the two other cases given that they are topologically identical92Te3 on graphene substrates, 2Te3 domains that are aligned with the graphene lattice, 2Te3 domains that are aligned with the buffer layer account more than 70% of the total amount of domains. This indicates that the amount of domains with a certain orientation is not only affected by the surface chemistry, but also by the growth mode and growth rate of the nucleated layers.Based on these considerations, we conclude that the different nucleation mechanisms of Sb2Te3 and the substrates. If this interaction is solely due to vdW bonding or also involves chemisorption, as for example observed at a hetero-organic interface2Te3 is deposited on monolayer epitaxial graphene and quasi freestanding bilayer graphene, because the same lattice mismatch can be obtained with a much higher density of coincidence lattice sites (rotated by 30°). A possible explanation for this observation is that the relatively weak interaction between the layers reduces the influence of the density of coincidence lattice points on the energy difference between the different orientations. This makes the occurrence of coincidence lattice with large distances between coincidence lattice sites more likely. However, the exact nature and the energetics of bonding between 2D bonded materials is still unclear, as pointed out above, and requires more detailed investigations. Nevertheless, these observations do show that lattice matching still plays an important role during vdW epitaxy and even suggest that coincidence lattice formation might be natural for vdW epitaxy on 2D bonded materials. This implies that the lattice parameter of 2D bonded materials is an important parameter to consider for the design and fabrication of vdW heterostructures.The observation of coincidence lattices between two 2D bonded materials indicates that there is a significant interaction between Sb2Te3 films grown on three different kind of graphene substrates: monolayer epitaxial graphene substrates, quasi freestanding bilayer graphene substrates and on the SiC buffer layer substrates. Raman spectroscopy revealed that graphene forms a stable interface with Sb2Te3. Furthermore, it was shown that the in-plane alignment between substrate and epilayer is determined by the formation of coincidence lattices between Sb2Te3 and graphene (monolayer and bilayer graphene substrates) or the surface corrugations of the buffer layer, demonstrating that there is a significant interaction between 2D materials and that lattice matching still occurs during vdW epitaxy. Contrary to early reports on vdW epitaxyIn summary, the fundamentals of vdW epitaxy were studied by using Sb2Te3 thin films were deposited on three different kind of graphene substrates  using molecular beam epitaxy (MBE). The fabrication and characterization of epitaxial graphene, bilayer graphene and buffer layers on top of SiC(001) substrates used in this study is described in detail elsewhere2Te3 and graphene was considered. Using density functional theory Jin and Jhi calculated the binding energy between graphene and Sb2Te3 and found it to be ~41 meVBT, where kB is Boltzmann’s constant and T the temperature, when T = 475K/ 202 °C. The binding energy thus puts an upper limit on the deposition temperature that can be used. Indeed, we observe a total desorption from the graphene surface for temperatures above 150 °C. Initial deposition with a growth temperature of 135 °C, which is approximately 100 °C below normal deposition conditions2Se3 filmsSbin situ using RHEED using a 20 keV electron acceleration voltage and ex situ using AFM (Veeco Nanoscope III) operated in tapping mode. and XRD  using Cu Kα1 radiation (λ = 1.540598 Å). The Raman spectra were obtained by exciting the Sb2Te3 and graphene/SiC with a laser . The backscattered light was collected using a liquid nitrogen cooled charged coupled device detector without using any polarizer’s. The schematics in the The substrates and films were characterized How to cite this article: Boschker, J. E. et al. Coincident-site lattice matching during van der Waals epitaxy. Sci. Rep.5, 18079; doi: 10.1038/srep18079 (2015).


The paradigm of graphene transistors is based on the gate modulation of the channel carrier density by means of a local channel gate. This standard architecture is subject to the scaling limit of the channel length and further restrictions due to access and contact resistances impeding the device performance. We propose a novel design, overcoming these issues by implementing additional local gates underneath the contact region which allow a full control of the Klein barrier taking place at the contact edge. In particular, our work demonstrates the GHz operation of transistors driven by independent contact gates. We benchmark the standard channel and novel contact gating and report for the later dynamical transconductance levels at the state of the art. Our finding may find applications in electronics and optoelectronics whenever there is need to control independently the Fermi level and the electrostatic potential of electronic sources or to get rid of cumbersome local channel gates. In general, contacts behave as passive elements impeding the performance of electronic devices. In high mobility graphene transistors the contact resistance competes with the channel resistance already for channel lengths in the hundred nanometer range24510121516et al.W between graphene and metal; its equilibrium density is governed by ΔW and the screening energy ϵc of graphene  on both sides. With kFd/2π ~ 1, where kF is the electronic wave number in the least doped side, sharp p-n junctions have a high transparency Vch) and two interconnected source and drain contact gates (bias Vcont) as sketched in R(Vch), where R is strongly modulated by Vcont at large channel p- and n-doping  upon channel A graphene contact is a composite element made of two junctions in series: a vertical metal-graphene junction and an in-plane contact junction. The former stems from the momentum mismatch between zone-center metallic and zone-edge graphene electrons and the latter results from doping gradients at the contact edge. According to Giovanetti hene see  below. Hn-doping  while reL = 0.2 μm and W = 1.1 μm. Other samples have been fabricated using CVD graphene showing similar behaviors, with however a lower contrast due to longer and more diffusive channels (L = 0.5 μm); for simplicity we restrict ourselves to the data obtained on the exfoliated sample. The nanoscale packing of three electrodes  provides a vectorial control of the local electric field at the contact edge (Following ref. act edge : the twode (CPW)  used forR(Vch) for contact gate voltages Vcont = −1.2→1.2 V. As seen in the figure, contact gating efficiently modulates the device resistance away from charge neutrality point (CNP), R(Vch) being modulated by a factor 2.3 for Vch < 0 and 1.3 for Vch > 0. By contrast, the CNP conductance remains unchanged indicating a mobility limited conductance  is presented in R(Vch) for three representative values of the contact gate voltage: at negative Vcont = −1.2 V (panel-c) the curve is most asymmetric, indicating a strengthening of the pristine p-doping of Pd contacts. The asymmetry is opposite, although less pronounced, for Vcont = +1.2 V (panel-d) suggesting the reversal from p- to n-doping of the contacts. At Vcont = 0.2 V (panel-e) the curve is symmetric and corresponds to neutral contacts. The resistance minimum, R = 300 Ω, is achieved for p-type contacts and channel doping; it deviates from the ballistic case (dotted line in μm4R(Vcont) cuts for p- and n- channel doping for contact junction dominated regimes. The curves show a maximum and an asymmetry which are typical of ordinary transfer curves, confirming our ability to drive the contact doping through neutrality. These curves are more direct evidence of contact doping reversal than the conventional ones obtained with remote back gates where polarity reversal is signaled by a smeared second peak6R(Vch) (given a channel polarity) confirming the small electrostatic coupling between contact and channel gates, the R(Vcont) curves being mainly shifted upward on decreasing channel doping due the finite carrier mobility contribution of the channel. The main features of the R data are well reproduced in the plot of A color plot representation of the Rmg in parallel with a metal-graphene capacitance Cdl (per unit area), the later accounting for the charge double layer formed at the metal-graphene interface as a result of work function mismatch ΔW. Whereas a metallic contact sets the electrochemical potential of the contacted graphene, both the electrostatic Vgr and the chemical To describe the contact properties we use an electrostatic model for the contact doping from ref. one obtains the expression for the chemical potential of contacted graphene (3). In addition we plot in ϵW, which is tuned by the local bottom gate voltage Vcont according to the capacitance level arm ratio Ccont/Cdl. Ab-initio calculationsCdl ~ 15–30 fF/μm2. However the metal graphene coupling is process dependent and experiments show large scatter in the contact resistance presumably due to doping variations. In addition, our measurements show that, for a given sample, the contact coupling eventually depends also on thermal cycling. The term ϵc defines the screening energy scale of the gated contact assembly; at low doping Vch according to the usual parallel plate capacitor model.The doping polarity is determined by the sign of the effective electrochemical potential mismatch T(θ) of a potential step as function of the incident angle θ of carriers to the junction normal928w is the step length scale. As a benefit it provides analytic expressions for T(θ) for arbitrary junction lengthThe resistance is calculated using the lumped electrical elements description in RK in Rch in μ = Const. Based on this simple model we can reproduce in R in Cch = Ccont = 2.3 fF/μm2 and the junction length d = 30 nm from device geometry. The fitting parameters are Rmg = 55 Ohm, μ = 6000 cm2 V−1 s−1, Cdl = 4.5 fF/μm2 (ϵc = 58 meV) and ΔW = 50 meV. From these numbers we deduce the investigated contact doping range lB = μEF/evF ~ 60 nm (at EF ~ 0.1 eV) that is larger than the junction length. In addition we have accounted for a gaussian broadening of the density corresponding to an experimental minimum sheet carrier concentration of W, Cdl, Rmg, μ and n0. The last two ones are determined as usual by the R(Vch) dependence at DP while the three others control R(Vch) away from DP. They can be determined thanks to the additional Vcont dependence controlling the asymmetry of the R(Vch) curves from which we deduce the contact parameters ΔW, Cdl. As mentioned above, we finally deduce Rmg from the (constant) symmetric part of the R(Vch) curves. We found a work function mismatch between Pd and graphene of ΔW = 50 meV while the tabulated value is on the order of 1.1 eVet al. we should take into account a metal-graphene chemical interaction, that depends on the metal-graphene distance and scales down the work function mismatch. For a typical distance of 0.3 nm the correction is large, ~0.9 eVWth ~ 200 meV some factor above the measured value. This discrepancy can be attributed to a process induced chemical doping. A superiority of our dual gate transistor is that it provides a direct estimate of this effective work function mismatch as well as the screening energy.where on tools , we havem2 ϵc = 5 meV and m2 ϵc = 5 meV and gm in Vds < 0.3 V to achieve a finite gm while preserving linear conditions Vcont = 0 V) where the device is most symmetric. We first note that channel and contact gating are equally efficient with a transconductance level Vcont = −0.9 V) reaching a value as large as 0.6 mS/μm/V. These transconductance levels are very promising for applications in RF transistors that would however require low-resistance contact gates.Based on the understanding of the DC properties of our dual gate KBT, we proceed by investigating its dynamical properties. Especially, we show here that the performance of the transistor, driven from its contact gate, can be as good as when it is driven from the usual channel gate. Here we are restricted to the 0.1–3 GHz frequency range, due to the combined effects of the gate resistance DC to RF  is more Finally, we show in In conclusion we have demonstrated contact gating both at DC and RF, in a dual gate Klein barrier transistor using graphene on boron nitride with a set of local bottom gates. Our device operates in the fully bipolar regime with transport properties that are accurately mapped with a ballistic Klein tunneling junction model. Active contact gating is demonstrated at RF frequency, and compares favorably with conventional channel gating. This finding opens new routes for graphene electronics and optoelectronics by using low resistance bottom gates and/or separate contact gates to tune independently the drain and source doping.How to cite this article: Wilmart, Q. et al. Contact gating at GHz frequency in graphene. Sci. Rep.6, 21085; doi: 10.1038/srep21085 (2016).


P = 0.002) and back-turning force (P = 0.002) compared with women. Subjects with BMI ≥27 kg/m2 had significantly higher side-turning force (P = 0.007) and back-turning force (P = 0.007) compared with those with BMI < 27 kg/m2. After adjusting for other covariates, age positively correlated with back-turning time (P = 0.033) and negatively correlated with side-turning speed (P = 0.005), back-turning speed (P = 0.014), side-turning force (P = 0.010), and back-turning force (P = 0.016), respectively. Turning times negatively correlated with time to reach peak pressure (P = 0.008). Our system was effective in detecting changes in turning swiftness in the bed-ridden subject.We developed a mobility detection system to analyze pressure changes over time during side-turns in 29 healthy volunteers  with a mean age of 46.1 ± 19.64 years (ranging from 23 to 86 years) in order to determine the effect of gender, age, and BMI on performance during bed postural change. Center of gravity (COG) location, peak pressure of counteraction, and time to reach peak pressure were the main outcomes used to gauge the ability to make a spontaneous side-turn. Men exhibited significantly higher side-turning force ( Determination of body position on a mattress is important for both management and prevention of bedsores in the bed-ridden patient and prevention of muscle atrophy in stroke patients. The development of pressure ulcers is a significant health concern, especially in the elderly population, as pressure ulcers can lead to serious systemic infections , 2. ApprPeriodic postural change is the key to prevention of deep tissue injury and subsequent pressure ulcer development. However, to our knowledge, there is no objective technology available to evaluate turning ability. In addition, postural training and monitoring of turning motion recovery are needed in the elderly, the stroke patient, and the disabled.At present, patient body position is measured by visual inspection or by analysis of either a video monitoring system or expensive, high-resolution arrays of pressure sensors –7. Due tWe designed a low-cost mobility detection system not only to monitor spontaneous bed turning but also to assess turning ability in the bed-ridden patient. This mobility detection system combined a sensor mat (using a minimum number of sensors) with data analysis software to monitor turning ability. This system analyzed pressure changes over time during side-turns in 29 healthy subjects. Gravity center location and velocity during movement, time to complete a side-turn, peak counteraction pressure, and time to reach peak pressure (turning swiftness) were the parameters used to gauge the ability to make a spontaneous side-turn in bed.This study was approved by the Institutional Review Board of Tri-Service General Hospital, National Defense Medical Center. All subjects gave their written informed consent prior to participation in the study.In this study, normal healthy volunteers were asked to lie in the center of the bed and listen to instructions regarding bed turning Figures . Each suData was collected over 20 turns back and forth for each subject. The force generated on the bed surface was recorded and analyzed, as described below.XY plane, as follows:The mobility detection system was composed of four strain gauges  and additional data analysis software . The strAs graphically depicted in aix∗Fi refers to the four load cells to withstand the forces generated on the X-axis to the total moment, and aix is the x-coordinate of four load cells, ∑aiy∗Fi refers to the four load cells to withstand the forces generated on the Y-axis to the total moment, and aiy is the y-coordinate of four load cells.∑The analog pressure readings were sent to a signal processing unit and then to the NI-DAQmx8.9  which performed analog to digital conversion. The resulting digital signals were input to a PC for data analysis . The datIn summary, this study was designed to monitor coF or center of gravity (COG) changes. To clarify, (i) velocity of COG is equivalent to “turn/back speed,” (ii) peak pressure of counteraction is equivalent to “turn/back force,” and (iii) time to reach peak pressure is equivalent to “turn/back peak time.” Main outcomes of the study were velocity of COG, peak pressure of counteraction, and time to reach peak pressure . Secondary outcomes included movement distance of COG, side-turn time, and location of COG .The following terms were used throughout the study.Turn time (sec) or side-turn time refers to the time to complete the left (or right) side-turn from the back position (resting position); TL (cm) or movement distance of COG refers to gravity distance traveled to complete the left (or right) side-turn; turn speed (cm/sec) or velocity of COG refers to the speed used to complete the left (or right) side-turn and was equal to TL divided by turn time; turn peak time (ds) or time to reach peak pressure refers to turning swiftness when completing a side-turn; turn force (kg·m/s²) or peak pressure of counteraction refers to maximum reaction force expended to complete either the left (or right) side-turn; back time (sec) or side-turn time refers to time to return to one's back from either the left (or right) side-turn; BL (cm) or movement distance of COG refers to distance traveled upon returning to one's back after completing the left (or right) side-turn; back speed (cm/sec) or velocity of COG refers to the speed of turning onto one's back from either the left (or right) side-turn; back peak time (ds) or time to reach peak pressure refers to turning swiftness when completing a back-turn; back force (kg·m/s²) or peak pressure of counteraction refers to maximum reaction force expended to complete the turn onto one's back from either the left (or right) side-turn; turn-weight ratio or location of COG refers to the ratio of turn force to weight; back-weight ratio or location of COG refers to the ratio of back force to weight.r > 0.8) and 0.75 (r > 0.75), respectively. The force sensor used in this study met both criteria with high validity and reliability.Using a 30 kg standard, each point of the test was repeated ten times, and the test-retest reliability (0.947 for position detected and 0.986 for weight measured) and concurrent validity (0.927 for position detected and 0.924 for weight measured) of the results were tested with regard to location and the weight measured, respectively. Both validity and reliability were found to be above 0.9. According to a systematic review by Wind et al. , the criP < 0.05 indicated statistical significance.Continuous variables were summarized using mean ± SD and categorical variables were expressed as frequencies and percentages. The intrarater reliability of parameters that were used to evaluate turning ability was measured by intraclass correlation coefficients (ICCs). The repeated measures analysis of variance (ANOVA) was used to detect the within-subject (side-turning) and between-subject effects  on various parameters related to turning ability. To investigate the factors associated with turning ability, the generalized estimating equation (GEE) model, with an identity link function, was applied to accommodate the correlated data of repeat measurements within the same subjects. All statistical analyses were performed using SAS software version 9.2 . A two-tailed 2 (ranging from 17.15 to 31.55 kg/m2).A total of 29 healthy volunteers, consisting of 17 males (58.6%) and 12 females (41.4%), were enrolled in the study. Their demographics are summarized in For evaluation of intrarater reliability, a separate pilot study of 10 subjects (not involving the 29 subjects used in this study) was conducted and 20 repeat measurements per each parameter  were taken by one physician (rater) for each subject.Before the main study began, we wished to investigate reliability of these parameters for measuring turning ability within the same physician (rater). The intrarater reliability of parameters that describe turning ability was quantified using intraclass correlation coefficients (ICCs) . An ICC P = 0.002) and back force (P = 0.002) when compared with women (2had significantly higher turn force (P = 0.007) and back force (P = 0.007) when compared with those who had BMI < 27 kg/m2 (P = 0.025) compared to those < 65 years old  and back force (P = 0.041) than women; (ii) BMI positively correlated with higher TL (P = 0.047), turn force (P < 0.001), and back force (P < 0.001), respectively; (iii) age positively correlated with back time (P = 0.033) and negatively correlated with turn speed (P = 0.005), back speed (P = 0.014), turn force (P = 0.010), and back force (P = 0.016), respectively; (iv) turning times negatively correlated with turn peak time (turning swiftness) (P = 0.008).The GEE models included all variables in the multivariate analysis. After adjusting for other covariates, factors associated with parameters related to turning ability were as follows: (i) men had higher turn force (2 had significantly higher side-turning force (and back-turning force) compared with those who had BMI < 27 kg/m2. Interestingly, subjects ≥ 65 years old took significantly longer to reach peak turning swiftness compared with those subjects < 65 years old. Multivariate analysis showed that age positively correlated with back-turning time and negatively correlated with side-turning speed, back-turning speed, side-turning force, and back-turning force.Our mobility detection system was the first to quantify turning ability in the elderly subject, underscoring the originality of this research. In addition, we found that men exhibited significantly higher side-turning force and back-turning force compared with women. Healthy volunteers with BMI ≥ 27 kg/mSlow turning speed in the elderly may arise from several causes including loss of skeletal muscle mass and force  as well The ability to complete a side-turn is an important activity in bed-ridden patients , as a goThe prevention of bedsores through side-turns is a very important and relevant topic. Several factors are involved in the development of bedsores and can be divided into intrinsic versus extrinsic factors. Intrinsic factors include nutrition and skin humidity, while extrinsic factors include direct skin pressure, shear forces, and/or friction . GeneralOnce bedsores develop, they represent an acute health condition that results in increased cost and suffering over months or even years. Effective ulcer prevention and early detection is, therefore, necessary. Strong motivation for a computerized mobility detection system arises from the growing shortage of trained health care providers  and the Our study had several limitations. Participants were all healthy volunteers with a mean age of 46.1 ± 19.64 yrs (ranging from 23 to 86 yrs). Thus, no patients at risk for developing bed sores  were included in the study. Further validation of our method in patients with (or at high risk for) impaired side-turning on beds is required. Overnight monitoring of older healthy individuals and patients using our mobility detection system is also required for complete assessment. Reliability of the mobility detection system should also be examined by video monitoring system. Since this is the first study of its kind to analyze turning swiftness, further clinical trials examining a larger aging population are required to confirm our results. In particular, turn angle, turn angle speed, and other related measures should be considered in future clinical trials since they are less dependent on the height or width of the participants.Our mobility detection system has proven to be effective in detecting changes in turning swiftness on beds. It is effective and easy to use. However, further validation with patients at high risk for impaired side-turning on beds is required.


There is no consensus regarding the phenomenology, classification, and diagnostic criteria of cybersex addiction. Some approaches point toward similarities to substance dependencies for which approach/avoidance tendencies are crucial mechanisms. Several researchers have argued that within an addiction-related decision situation, individuals might either show tendencies to approach or avoid addiction-related stimuli. In the current study 123 heterosexual males completed an Approach-Avoidance-Task AAT;  modified In the last decade it has been discussed to extent the concept of addiction from substance-related to non-substance-related behaviors, which are frequently referred to as behavioral addictions . One domIn the current study, we investigated possible links between tendencies to approach or avoid pornographic stimuli and tendencies toward cybersex addiction. Such mechanisms have been shown to be crucial for addictive behaviors e.g., , while tAccording to approach, avoidance, ambivalence, and indifference. Approach and avoidance are competing action-tendency states. Approach is supposed to cause alcohol consumption whereas avoidance represents an oppositional process in which the urge to consume alcohol is suppressed. Further, ambivalence and indifference can be described as ambiguous states, which might be entered if the inclinations of the action-tendency states are balanced. In this context, ambivalence represents a high and indifference a low intensity of ambiguity. approach, while negative expectancies are likely to cause avoidance. Regarding different aspects of craving, approach is synonymous with an irresistible “wanting” and thereby able to elicit an automatic response. Contrary, avoidance is supposed to be a subjectively experienced process. Consequently, the approach/avoidance framework is in line with dual-process models highlighting the role of automatic and controlled processes for the development and maintenance of addictive behaviors . The mean age of first cybersex use was 15.61 (SD = 4.01) years. On average, participants used cybersex sites 3.66 (SD = 3.52) times per week, while spending timeM = 22.25 (SD = 14.22) minutes per visit. Only participants of legal age (at least 18 years-old) were recruited. Recruitment was done through local advertisements at the University of Duisburg-Essen (Germany) and online platforms. It was stated in the advertisements that explicit pornographic material would be presented. Students could collect credits, non-student participants were paid €10 for participation. All participants gave written informed consent prior to the experiment and were debriefed at the end of the study. The study was approved by a local ethics committee.In the present study a total of 123 heterosexual male participants were examined  to 5 . The stimulus set contained 10 different cybersex categories: heterosexual sex , homosexual sex  as well as single masturbating men and women. Each category consisted of five pornographic pictures showing sexually explicit scenes without fetish relevant material. The internal consistency was very good (Cronbach’s α = 0.954). The same paradigm was used in several other studies, except that 100 pictures (10 per category) were used  and after (t2) the pornographic picture rating on two horizontal sliders from 0  to 100 . By subtracting t1 from t2 measurement, Δ-scores representing a relative increase or decrease of sexual arousal  and need to masturbate (craving Δ need to masturbate) were calculated and used as an operationalization of craving.Additionally, as described by Participants performed a modified version of the AAT , in whicDuring instruction, participants completed 30 practice trials, which were separated into four rounds . After each round, participants were informed about the amount of correct reactions and could decide to repeat the round. The experimental trials were divided into four blocks with 80 trials each, resulting in a total of 320 trials. Every stimulus was presented once during one block in a semi-random order . Participants were randomly assigned to one of two experimental conditions, which differed with respect to the instruction in the first block . In the following blocks the instruction was inverted. The experimental condition was counterbalanced across participants. By separating the type of instruction (direct vs. indirect), previous studies used different versions of the AAT. Versions with direct instructions e.g.,  includedTo analyze AAT data, median RT scores were calculated since medians are less vulnerable with respect to RT outliers than mean scores . RTs < 2Table 1. The AAT was programmed using Presentation®software .Additionally, an overall effect score  was calculated by subtracting the median RT for all neutral stimuli from the median RT for all pornographic stimuli . While the movement direction in specific trials is not taken into account for this measure, negative values indicate that participants were faster to respond to pornographic stimuli , while positive values point toward slower RTs for pornographic stimuli . Thus, the overall RT score is equivalent to the assessment of indirect attentional biases in substance use disorders  than to never) to 5 (= very often). The internal consistency of the s-IATsex in this study was good (Cronbach’s α = 0.846). It can be divided into the subscales loss of control/time management  and craving/social problems . Both s-IATsex time and s-IATsex craving have a possible range of 6–30.To assess tendencies toward cybersex addiction a short version of the Internet Addiction Test s-IAT; , modifienever) and 5 (= very often) and can be separated into the subscales loss of control , coping , and consequences . In this study, the internal consistency of the HBI was good (Cronbach’s α = 0.885). Further, sensitivity toward sexual excitation was assessed by the Sexual Excitation Scale  to 4 (= strongly agree), leading to an overall mean score of 6–24. At last, sociodemographic data as well as basic information with respect to pornography consumption were assessed.Additionally, as a measure of general problematic sexual behavior, the Hypersexual Behavioral Inventory was used HBI; . The HBIale SES; , which cThe subscales s-IATsex craving and HBI loss of control will be used as dependent variables for testing the hypotheses since these scales assess subjective consequences of craving more specifically than the sum scores of the s-IATsex and the HBI. Thus, these scores are preferred for investigating the relationship between tendencies to approach or avoid pornographic stimuli and craving as it is suggested by The instruments used in the current study can be separated into short-term  and long-term measurements . In this context, short-term measurements refer to reactive (immediate) responses, which might be influenced by environmental factors, such as preceding cybersex consumption. In contrast, long-term measurements rather resemble individual characteristics, which are supposed to remain stable over a longer period of time.t-tests. Effect sizes are reported according to r  and Cohen’s d . Quadratic relationships between two variables were evaluated using curve-linear regression analyses. Further, interactions between two variables as predictors of a single dependent variable were analyzed with hierarchical moderated regression analyses  = 32.79; p < 0.001; d = 4.11, indicating that heterosexual pictures were rated as significantly more sexually arousing. Regarding the evaluation of sexual arousal and the need to masturbate before (t1) and after (t2) the pornographic picture rating, two t-tests for dependent samples revealed higher subjective sexual arousal, t(122) = -9.05; p = 0.001; zd = 0.85, and a higher need to masturbate, t(122) = -7.30; p < 0.001; zd = 0.61, at t2 compared to t1 . These results indicate that due to watching pornographic pictures, participants experienced a state of being sexually aroused before starting the AAT. This is of particular importance since sexual arousal and the need to masturbate are operationalized as craving measures, which are supposed to be linked to tendencies to approach or avoid pornographic stimuli.A one-sample M = -1.09, SD = 72.64) and the neutral approach/avoidance score  had negative mean values. These results indicate a mean tendency for avoiding both pornographic and neutral stimuli in the AAT, while this effect was stronger for neutral stimuli, t(122) = 8.52; p < 0.001; d = 0.87. In contrast, the overall RT score  had a negative mean value, which indicates that participants on average had no attentional bias toward pornographic stimuli .Descriptively, the pornographic approach/avoidance score  = 0.33, p = 0.567, which indicates that no linear relationship between the two variables exists in the data. In a second step the squared pornographic approach/avoidance score was included, which led to a significant explanation of 23.7% of the s-IATsex craving variance, ΔR2 = 0.234, F = 18.80, p < 0.001. This estimated curve  indicates that individuals with a high s-IATsex craving tended to either show approach  or avoidance  inclinations with respect to pornographic stimuli. Further regression values are summarized in Table 4.To test whether the relationship between the pornographic approach/avoidance score and the s-IATsex factor craving was not linear but quadratic, a curve-linear regression analysis was calculated. In a first step the pornographic approach/avoidance score was entered but did not significantly explain s-IATsex craving variance, p = 0.239).As a manipulation check, a second analysis was calculated to investigate the relationship between the s-IATsex craving and the neutral approach/avoidance score. Here, no significant quadratic relationship could be found  = 18.83, p < 0.001. In the second step, the pornographic approach/avoidance score led to a significant increase of variance explanation, Δ2R = 0.029, ΔF = 4.19, p = 0.043. In the third step, the interaction of the SES and the pornographic approach/avoidance score led to a significant increase of variance explanation, Δ2R = 0.044, ΔF = 6.62, p = 0.011. Overall, the regression model was significant and explained 20.8% variance of the s-IATsex craving, F = 10.41, p < 0.001.To investigate the relationship between sensitivity toward sexual excitation (SES), tendencies to approach or avoid pornographic stimuli (pornographic approach/avoidance score), and tendencies toward cybersex addiction, a hierarchical moderated regression analysis with the s-IATsex factor craving as dependent variable was calculated . The slope of the regression line representing approach tendencies (1 standard deviation above the mean) was not significantly different from zero, t = 1.71, p = 0.090. In contrast, the slope of the regression line representing avoidance tendencies (1 standard deviation below the mean) was significantly different from zero, t = 5.50, p < 0.001, indicating that a high SES, accompanied by avoidance tendencies resulted in a high s-IATsex craving score. When using tendencies to approach or avoid neutral stimuli  as moderator, no significant interaction could be found (p = 0.196).To investigate the observed moderation effect in more detail, simple slopes were analyzed  = 34.52, p < 0.001. In the second step, the pornographic approach/avoidance score did not lead to a significant increase of variance explanation, Δ2R = 0.017, ΔF = 2.70, p = 0.103. In the third step, the interaction of the HBI loss of control and the pornographic approach/avoidance score led to a significant increase of variance explanation, Δ2R = 0.037, ΔF = 6.02, p = 0.016. Overall, the regression model was significant while explaining 25.7% variance of the s-IATsex craving, F = 15.10, p < 0.001. Further values for both moderated regression analyses are summarized in Table 5.A second model was calculated to investigate the relationship between the control component of problematic sexual behavior (HBI loss of control), tendencies to approach or avoid pornographic stimuli (pornographic approach/avoidance score), and tendencies toward craving components in cybersex addiction. In the first step, the Figure 3B). The slope of the regression line representing approach tendencies (1 standard deviation above the mean) was significantly different from zero, t = 2.85, p = 0.005. The slope of the regression line representing avoidance tendencies (1 standard deviation below the mean) was also significantly different from zero, t = 6.14, p < 0.001, indicating that both approach and avoidance toward pornographic pictures, accompanied by a high HBI loss of control resulted in a high s-IATsex craving score. Similar to the first moderated regression analysis, using tendencies to approach or avoid neutral stimuli  as moderator showed no significant interaction (p = 0.166).Similar to the first model, the simple slopes were analyzed  = 34.52, p < 0.001. In the second step, the SES led to a significant increase of variance explanation, Δ2R = 0.052, ΔF = 2.63, p = 0.004. In the third step, the pornographic approach/avoidance score led to a significant increase of variance explanation, Δ2R = 0.024, ΔF = 4.47, p = 0.037. Overall, the regression model was significant and explained 30.1% variance of the s-IATsex craving, F = 17.04, p < 0.001. Further regression values are summarized in Table 5.Additionally, to investigate whether the HBI loss of control scale, the SES, and the pornographic approach/avoidance score have an accumulating effect on tendencies toward cybersex addiction, a linear regression analysis with the s-IATsex factor craving as dependent variable was calculated. In the first step, the r = 0.227, p = 0.011) and the average time spent on cybersex sites during one visit . However, no significant relationships could be found between the frequency of weekly cybersex use and HBI loss of control , SES  as well as craving Δ sexual arousal/masturbation and AAT scores . Similarly, there were no significant relationships between the average time spent on cybersex sites during one visit and HBI loss of control , SES  as well as craving Δ sexual arousal/masturbation and AAT scores .In order to investigate possible relationships between actual cybersex use and measurements related to cybersex addiction, several additional correlations were calculated. There were positive relationships between the s-IATsex factor craving and both the frequency of weekly cybersex use (The main result of this study is that tendencies toward cybersex addiction seem to be related to approach/avoidance tendencies. First, individuals who reported higher symptoms of cybersex addiction tended to either approach or avoid pornographic pictures, while this was not the case for neutral stimuli. Second, we found that sensitivity toward sexual arousal as well as problematic sexual behavior interacted with approach/avoidance tendencies toward pornographic pictures, leading to an accumulating effect on tendencies toward cybersex addiction. Again, no significant interactions were found for approach/avoidance tendencies toward neutral stimuli.The results of this study preliminary indicate that approach/avoidance tendencies might be connected to excessive cybersex use and potentially to cybersex addiction. This is also in line with the data provided by Regarding the interactions between specific predispositions toward cybersex and approach/avoidance tendencies, it is interesting to note that problematic sexual behavior led, accompanied by either approach or avoidance tendencies, to high subjective symptoms of cybersex addiction. Contrary, the interaction between sensitivity toward sexual arousal and approach/avoidance tendencies only showed a significant effect for avoidance tendencies. This finding might be explained by referring to Thinking further, cybersex use characteristics such as the frequency of weekly cybersex use and the average time spent on cybersex sites during one visit were not connected to immediate measurements related to cybersex addiction like subjective craving or the dependent variables of the AAT. Thus, these results facilitate the assumption that the observed approach/avoidance tendencies could be derived from neural sensitizations due to a long-term exposure of cybersex-related cues. Moreover, actual cybersex use might be connected with the maintenance of an addictive use of cybersex, while our results suggest that the AAT rather measures effects which might be connected to a dysfunctional cybersex use, carried out over a longer period of time. However, further empirical evidence is needed to evaluate whether the AAT is a short-term or a long-term measurement.Another side result of this study is that problematic sexual behavior, a high sensitivity toward sexual excitation, and high craving scores were positively associated with the overall RT score, which means that these variables correlated with slower RTs in pornographic compared to neutral trials. This finding is consistent with results from studies investigating attentional biases in addictive behaviors (for review see Future studies could further aim on expanding the focus of interest by including positive and negative expectancies as possible predictors for approach/avoidance tendencies in analogy to the proposed framework by Moreover, it could be beneficial to investigate if competing neural networks are involved in approach/avoidance reactions. In this context, studies already showed parallels to the dual-process model by Thinking further, previous studies mostly investigated linear relationships between approach/avoidance tendencies and addiction-related measurements, whereas such an approach might not cover the complexity of addictive behaviors. However, the most prominent belief seems to be that only approach-biases are connected to the development and maintenance of addictive behaviors, although this assumption is not entirely supported by existing findings. For instance, some studies reported approach-biases in individuals with problematic substance use e.g., , whereasAt last, it might be useful to investigate to which extent approach/avoidance tendencies influence the development and maintenance of cybersex addiction. Here, longitudinal study designs could be beneficial. Moreover, such an approach seems plausible since the results of the current study suggested the AAT to measure effects due to long-term cybersex use, while more research is necessary to justify this assumption.First of all, it has to be noted that the curve-linear regression analysis used to test the assumed quadratic relationship between approach/avoidance tendencies and craving-related symptoms of cybersex addiction may rather be considered as an exploratory method. Moreover, the results are not emphasizing a perfect quadratic relationship. Therefore, the findings have to be interpreted with caution and need to be replicated. Nonetheless, these results at least point toward a non-linearity of the relationship between approach/avoidance tendencies and cybersex addiction. Since we only included heterosexual male participants, our results can hardly be generalized to women or homosexual individuals. Further, the majority of the sample consisted of regular cybersex users, while a minority reported subjective symptoms in everyday life due to their cybersex use. Although, the investigation of disorders with analog samples offers many benefits , our finThe results of this study preliminary suggest that approach/avoidance tendencies might be mechanisms which are connected with cybersex addiction. More specific, it was shown that individuals with tendencies toward cybersex addiction revealed both approach and avoidance tendencies, which is in accordance with theories from substance dependency research . In combThe authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


Idiopathic pulmonary fibrosis (IPF) often accompanies lung cancer, and life-threatening acute exacerbation (AE) of IPF (AE-IPF) is reported to occur in 20 % of IPF patients who undergo lung cancer surgery. Pirfenidone is an anti-fibrotic agent known to reduce disease progression in IPF patients. A phase II study was conducted to evaluate whether perioperative pirfenidone treatment could reduce the incidence of postoperative AE-IPF patients with lung cancer.Pirfenidone was orally administered to IPF patients who were candidates for lung cancer surgery; pirfenidone was dosed at 600 mg/day for the first 2 weeks, followed by 1200 mg/day. Surgery was performed after at least 2 weeks of 1200-mg/day administration. The primary endpoint was non–AE-IPF rate during postoperative days 0–30, compared to the null value of 80 %, and the secondary endpoint was safety. Radiologic and pathologic diagnoses of IPF and AE-IPF were confirmed by an independent review committee.p = 0.01]) in the FAS, and in 38/39 patients  occurred in 1 patient, after AE-IPF; no other grade 3–5 adverse events were observed.From June 2012 to January 2014, 43 cases were enrolled, and 39 were eligible . Both pirfenidone treatment and surgery were performed in 36 patients (per protocol set [PPS]). AE-IPF did not occur in 37/39 patients .This clinical trial was registered with the University Hospital Medical Information Network (UMIN) on April 16th, 2012 (Registration Number:  Idiopathic pulmonary fibrosis (IPF) is the most common interstitial lung disease, and has a histological appearance of usual interstitial pneumonia (UIP). IPF is known to be a risk factor for lung cancer  and is oThe Assessment of Pirfenidone to Confirm Efficacy and Safety in Idiopathic Pulmonary Fibrosis (ASCEND) study group recently reported that pirfenidone, oral anti-fibrotic agent, significantly reduced disease progression, as reflected by lung function, exercise tolerance, and progression-free survival, in a phase III trial in patients with IPF , 12. HowPatients were required to have the UIP/possible UIP pattern criteria published by ATS/ERS/JRS/ALAT in 2011  by high-This was a multicenter, single-arm phase II study designed to evaluate the efficacy of perioperative pirfenidone treatment on the reduction of postoperative AE-IPF in Japanese patients with lung cancer. The primary endpoint was non–AE rate during postoperative days 0–30, and the secondary endpoint was safety. The expected non–AE rate was set at 95 %, and the non–AEthreshold was set at 80 %, because the non–AE rate in patients who did not receive perioperative pirfenidone treatment was assumed to be ≤80 % based on the literature , 15. A tRadiologic and pathologic diagnoses of IPF-AE were confirmed by a central review committee. To validate the institutional diagnosis of IPF, preoperative HR-CT and pathological samples obtained by surgery (non-cancerous lesions) were collected from each participating institute for central review. Two radiologists with expertise in interstitial lung disease (S.S. and T.I.) initially evaluated the HR-CT data independently and then developed a consensus report after discussion. Two pathologists with expertise in interstitial lung disease (J.F. and K.H.) initially evaluated the pathological samples independently and then developed a consensus report after discussion. These experts followed the international IPF diagnostic criteria published in 2011 . The repEach participating institute diagnosed AE-IPF according to the definition published by the Japanese Respiratory Society  as folloPirfenidone  at a dose of 600 mg/day was orally administered to patients who planned to undergo surgery for the first 2 weeks; the dose was then increased to 1200 mg/day for the next 2–4 weeks. The administration dose and dose-increase interval were established according to the protocol included in the Japanese pirfenidone package insert, which was based on the results of the Japanese pre-authorizing phase III trial . SurgeryP-values were calculated using binomial tests. A p-value <0.05 was considered significant. All statistical analysis was performed using SAS version 9.2 .In the primary analyses, the non–AE rate was based on the full-analysis set (FAS) following the intent-to-treat principle. n = 2), a history of chemotherapy (n = 1), and initiation of pirfenidone prior to registration (n = 1). Thus, 39 patients comprised the FAS. Patients included 33 males (84.6 %) with a median age of 68.0  years, and 38 patients had Hugh-Jones grade I/II activity (97.5 %). Among the FAS cases, two patients stopped pirfenidone administration before surgery due to patient request, and surgery was cancelled for one patient because metastatic lesions were identified on further examination. Therefore, both pirfenidone treatment and surgery were performed in 36 patients (per protocol set [PPS]). All of the PPS patients had received pirfenidone 1200 mg/day for >2 weeks at the time of surgery. The mean time at which pirfenidone was stopped around surgery was 18.4 h. Characteristics of FAS and PPS patients were very similar , adenocarcinoma , and other minor types. Pathological cancer stages included stage I/II . With respect to IPF diagnosis, the central review board diagnosed 39 of the 43 registered cases as IPF and the remaining 4 cases as not IPF . Compared to the central review by the professional radiologist/pathologist/respirologist, the accuracy of the preoperative radiological diagnosis of each institution was 90.7 %. Four not-IPF cases were included in the FAS and the PPS to adhere to the intent-to-treat principle. With respect to efficacy, we also selected the confirmed IPF cases from the PPS and analyzed them separately .From June 2012 to January 2014, 43 patients from 17 Japanese institutions were enrolled. Although all patients initiated pirfenidone therapy, 4 patients were deemed ineligible due to severe heart disease  (Table n = 1), anorexia (n = 4), nausea (n = 4), somnolence (n = 1), dizziness (n = 2), malaise (n = 2), anemia (n = 2), hypoalubuminemia (n = 2), alkaline phosphatase elevation (n = 2), aspartate aminotransferase elevation (n = 3), alanine aminotransferase elevation (n = 3), γ-glutamyltransferase (GGT) elevation (n = 5), creatinine elevation (n = 1), hyponatremia (n = 3), and hyperkalemia (n = 1); however, all of these events were grade 1 or 2 according to the Common Terminology Criteria for Adverse Events (CTCAE) version 4.0 scale. Safety in the postoperative phase was evaluated in 37 patients in the FAS who underwent surgery. Fewer patients than those in the FAS who underwent surgery were evaluated for postoperative safety, because we did not require reporting of clinical data, except for the occurrence of AE-IPF, for patients who quit pirfenidone administration prior to surgery. The following adverse events were observed postoperatively: anorexia (n = 6), nausea (n = 3), diarrhea (n = 1), dizziness (n = 1), malaise (n = 2), respiratory failure (n = 1), dyspnea (n = 6), pulmonary fistula (n = 2), postoperative hemorrhage (n = 1), cough (n = 1), atrial fibrillation (n = 1), wound dehiscence (n = 1), pneumonitis (n = 1), dysgeusia (n = 1), white blood cell decreased (n = 2), neutrophil count decreased (n = 1), anemia (n = 4), hypoalbuminemia (n = 19), alkaline phosphatase increased (n = 8), blood bilirubin increased (n = 1), aspartate aminotransferase increased (n = 8), alanine aminotransferase increased (n = 6), GGT increased (n = 6), hyponatremia (n = 8), hypokalemia (n = 3), and hypocalcemia (n = 3). Among these, 1 case of increased aspartate aminotransferase and 1 case of hyponatremia were reported as grade 3; 1 case of anorexia, 1 case of respiratory failure, and 1 case of dyspnea were reported as grade 4; and 1 case of pneumonitis was reported as grade 5. The grade 4 respiratory failure and dyspnea and the grade 5 pneumonitis were determined to be due to AE-IPF.The safety of pirfenidone treatment in the preoperative phase was evaluated in all patients who received pirfenidone . The reasons for the two surgery cancellations were discovery of metastatic lesions and necessity of cardiovascular surgery prior to lung surgery. Surgery was not cancelled in any patients due to pirfenidone-related adverse events.p = 0.01 under the null rate of 80 %]) in the FAS (Table p = 0.004 under the null rate of 80 %]) in the PPS. Among patients in the PPS, we also analyzed select IPF cases whose diagnoses were confirmed by the central review board (PPS-IPF). In the PPS-IPF, one of the 32 patients experienced AE-IPF . When compared to the threshold derived from historical controls, AE-IPF occurred at a significantly lower incidence in this study.AE-IPF was diagnosed in two patients : 82.7–99.4 %, The current study was designed to evaluate the safety and efficacy of perioperative pirfenidone treatment in the reduction of postoperative AE-IPF in patients with lung cancer. No serious adverse events caused by pirfenidone were observed, and the incidence of AE-IPF among patients treated with pirfenidone was significantly lower than the null hypothesis.The incidence of lung cancer have been reported to be >7-fold higher in IPF patients compared to the general population . ConversNo studies have yet demonstrated that any agents can prevent or decrease the incidence of postoperative AE-IPF . PirfeniAlthough AE-IPF is a well-known, life-threatening postoperative complication in patients with lung cancer accompanied by IPF, its reported incidence varies among studies; however, it generally ranges from 10 % to 20 % , 29, 30.Several studies have revealed that interstitial pneumonia subtype (UIP pattern or not) is a risk factor for postoperative AE-IPF , 31. HowThis study was not randomized but rather was a single-arm study in which historical data served as the control. When we combined the Japanese and international data for surgical lung cancer patients with idiopathic interstitial pneumonia published prior to the planning of the present study, the total incidence of AE was about 19 % (data not shown); therefore, we believe the null hypothesis set herein was appropriate. However, patient background and the influence of some types of patient management that may have been better than those reported in the literature could not be controlled in such a single-arm study. Because the reported background risks for AE also varied among studies, it is difficult to verify the difference between the background risk in this study and those of previous studies. For example, respiratory function and activity shown by Hugh-Jones classification of the registered patients were relatively good in the current study. Severe IPF is undoubtedly considered to be a high risk; however, functionally inoperable cases were not included in this surgical study, and in many cases IPF was newly detected by surgeons during preoperative examination. Perhaps due to such a situation bias, the previously reported preoperative respiratory functions were also almost normal –31. PostIn conclusion, this single-arm phase II study revealed that perioperative pirfenidone treatment is safe and promising for reducing AE-IPF after lung cancer surgery. These results encourage the planning of future confirmatory studies to compare pirfenidone to other treatments, such as nintedanib, for which the efficacy against progression of IPF has already been reported .AE: acute exacerbation; FAS: full analysis set; HR-CT: high-resolution computed tomography; IPF: idiopathic pulmonary fibrosis; JACS: Japanese Association of Chest Surgeons; PPS: per protocol set; UIP: usual interstitial pneumonia; WJOG: West Japan Oncology Group


Online communities are becoming increasingly important as platforms for large-scale human cooperation. These communities allow users seeking and sharing professional skills to solve problems collaboratively. To investigate how users cooperate to complete a large number of knowledge-producing tasks, we analyze Stack Exchange, one of the largest question and answer systems in the world. We construct attention networks to model the growth of 110 communities in the Stack Exchange system and quantify individual answering strategies using the linking dynamics on attention networks. We identify two answering strategies. Strategy A aims at performing maintenance by doing simple tasks, whereas strategy B aims at investing time in doing challenging tasks. Both strategies are important: empirical evidence shows that strategy A decreases the median waiting time for answers and strategy B increases the acceptance rate of answers. In investigating the strategic persistence of users, we find that users tends to stick on the same strategy over time in a community, but switch from one strategy to the other across communities. This finding reveals the different sets of knowledge and skills between users. A balance between the population of users taking A and B strategies that approximates 2:1, is found to be optimal to the sustainable growth of communities. Humans are unique in their ability to create public goods in non-repeated situations with non-kin. In larger groups cooperation is more difficult due to the higher temptation to free ride on the voluntary contributions of others . NeverthOnline communities are natural experiments that give us an opportunity to test possible mechanisms that explain cooperation in large groups. Controlled online experiments show that if participants can choose group members higher levels of cooperation can be derived . This suWe will demonstrate in this paper that assortment is not sufficient to derive high levels of contributions in online collaboration . Our anaFor our empirical analysis we investigate the answering records of nearly three million users over a period of six years from 110 online communities. We find that strategy A are important in decreasing the median waiting time for answers, while strategy B users help increase the acceptance rate of answers. Meanwhile, we find that users tend to use the same strategy over time within a communities, but may take different strategies across communities. This can be explained by the different skill sets between users. For example, an expert in science and engineering may try to answer challenging questions in the astronomy community, but only contributes to easy questions in the poker community see . The comWe propose “attention network” models to study the effect of answering strategies on the growth dynamics of communities. In attention networks nodes are questions and edges are the successive answering activities of users that connect two questions. We developed a theoretical network model in which the co-existence of two answering strategies B and A are represented by the mixture of two linking dynamics, i.e., preferential attachment  and its https://archive.org/details/stackexchange. This data set is a freely accessible, anonymized dump of all user-contributed content on the Stack Exchange network provided by Stack Exchange, Inc. under cc-by-sa 3.0 license (see https://creativecommons.org/licenses/by-sa/3.0/us/ for the explanation of this license). The downloaded data set contained the log files of 110 communities. The smallest community italian.stackexchange.com was created in November, 2013 and has 374 users, 194 questions, and 387 answers in our data set. The largest site stackoverflow.com (SO) was created in July, 2008 and has 2,728,224 users, 6,474,687 questions and 11,540,788 answers.Stack Exchange is a network of question and answer communities covering diverse topics in many different fields. We downloaded its database dump on January, 2014 from Stack Exchange uses a variety of methods to prevent spamming and malicious edits. These methods, including CAPTCHA (Completely Automated Public Turing test to tell Computers and Humans Apart) systems, script detection heuristics, new users limits, collective flagging of spam or offensive flags, auto-removal of items based on flags, and human moderators to handle flagged items, work together to form a human-machine combined system that keeps answers clean and effective . Before qij to a question j when a user i responds to it. Then we average this number over the m questions answered by user i to derive the average perceived difficulty as n users, which is qi < E(qi)) from users taking strategy B (qi ≥ E(qi)) (We use the number of existing answers as a proxy for the “perceived difficulty” of questions  in order≥ E(qi)) . To show≥ E(qi)) , the ave≥ E(qi)) , and the≥ E(qi)) .ρ = 0.29, p-value < 0.001), justifying the validity of using TrueSkill score as a measure of user skill level.The TrueSkill algorithm is a Bayesian ranking algorithm that estimates the skill levels of game players from competition results . Liu et Cik and Hi to quantify the strategic persistence of users within and across communities, respectively . We define Cik = 2/5 = 0.4. It is easy to know that Cik may take any values between 0 and 1 and a value close to 1 implies a high level of strategic persistence over time.We define two indices ectively . Cik meaHi = ((13/23) − 0.5)(1 − 0.5) = 0.13 so it is comparable with the other index Cik.We find that user 53 contributes to 23 communities during the time period under investigation. More specifically, he/she takes strategy A in 13 communities and strategy B in the remaining 10 communities. We identify A as the major strategy of user 53 and count the corresponding fraction 13/23. This variable varies from 0.5 (if a user randomly switches between the two strategies across communes) to 1 (if a user sticks to one strategy). We normalize it between 0 and 1 as The answering strategies of individual users can be understood from a network perspective, in which two questions are connected if they are answered sequentially by the same users  and edges (M), the daily increments of nodes (ΔN) and edges (ΔM), and the number of links per node (m = M/N) and its daily increments (Δm = ΔM/ΔN).From empirical data we construct a growing attention network for each of the 110 communities. The network properties we are interested in include the cumulative number of nodes  in each of the 110 communities and plot the two above discussed community performance indicators against a. It is observed that type A users help decrease waiting time and type B users contribute to the increase of answer acceptance rate. Therefore, a balance between these two types of users should be carefully chosen in order to optimize the community performance. In a approximates 0.63, i.e., the ratio of type A users to type B users is roughly 2:1. In As shown in We have shown a co-occurrence between an optimal ratio and the maximum community size. However, why a deviation from this optimal ratio leads to small community size remains unclear. Therefore, we develop a network model to quantify our assumptions on individual answering strategies in order to analyze the consequences of different ratios.We use “attention networks” to represent question and answer communities, in which nodes are questions and edges are the sequential answering activities of users. In attention networks, answering strategies based on the number of existing answers to questions can be interpreted as degree-based linking dynamics. As type A users prefer easy questions (low-degree nodes) and type B users favor difficult questions (high-degree nodes), when these two types of users move to a new question from old questions, they bring connections to the new node from old nodes of very different degrees. Therefore, we can naively assume that strategy A corresponds to “preferential attachment” , in whicf and 1 − f  to represent the probability of observing type A and B strategies, respectively. Note that f is different from the empirical value of a mentioned in the last section, as a was not the fraction of activities but the fraction of users. Using f as a parameter makes our model simple—so that we do not need to take care of the possible non-linear relationship between a and f, but our analysis can still provide insights into real systems, as it is easy to understand that a and f must be positively correlated. This is because f can be viewed as the multiplication between two variables, the fraction of users a and answering frequency distribution w. As w is always positive, f changes in the same direction as a.We use f, we quantify the probability p(k) of a new question being connected to a existing similar question of degree k asCombining “preferential attachment” and its revered version using the mixing ratio f = 0) and the “reversed preferential attachment” model (f = 1), respectively. Using the master equation technique [α has a minimum value 3 and always increases with f. We find that for a majority of communities the empirical value of α lies in the scope of [In two extreme cases this model degenerates to the “preferential attachment” model f = 0) anscope of , our modp(k) given by E(k)Ng, in which we use Ng to model the effect of network size. By summing E(k)Ng over all nodes in the network we obtain the total number of new nodes as ΔN = E(k)Ng+1. Substituting this condition into C. Putting these two conditions together, we derive the expected number of links obtained by a new node as Δm = CNh/E(k), in which Nh is the effect of network size. Using the conclusion of Besides degree distribution, the discussed linking rules also explain several scaling relationships observed in the growth dynamics of attention networks as presented by s degree . Meanwhi=N3-f2+g.Note tha=Nf-12+h.From Eqsδ); on the other hand, η). As a balance, f = 3 + 2g, is preferred in order to maximize the value of γ, i.e., to match the growth of answers with the growth of questions. As f and a are positively correlated, the derived optimimal value of f implies that there is also an optimal value of a, which is consistent with our empirical observation.To summarize, the above analysis explains why a balance between strategies A and B is crucial to the growth of communities. On one hand, We select three communities to compare the consequences of different mixing ratios between type A and B users, including a community for math questions , a community for questions about astronomy , and a community for questions about game development . As show by a = 0.67). According to our model, questions in ASTR will be addressed efficiently, but there will be a slow growth of new questions. This prediction is supported by a = 0.62) than the optimum. According to our model, in this community new questions will increase fast such that they can not be answered promptly. The fast increase of new questions is evidenced in The fraction of type A users in MATH is approximately 0.63, which is equal to the optimal value. In contrast, ASTR has more type A users Click here for additional data file.