In a silicon photomultiplier (SiPM), also referred to as multi-pixel photon counter (MPPC), many Geiger-mode avalanche photodiodes (GM-APDs) are connected in parallel so as to combine the photon ...counting capabilities of each of these so-called microcells into a proportional light sensor. The discharge of a single microcell is relatively well understood and electronic models exist to simulate this process. In this paper we introduce an extended model that is able to simulate the simultaneous discharge of multiple cells. This model is used to predict the SiPM signal in response to fast light pulses as a function of the number of fired cells, taking into account the influence of the input impedance of the SiPM preamplifier. The model predicts that the electronic signal is not proportional to the number of fired cells if the preamplifier input impedance is not zero. This effect becomes more important for SiPMs with lower parasitic capacitance (which otherwise is a favorable property). The model is validated by comparing its predictions to experimental data obtained with two different SiPMs (Hamamatsu S10362-11-25u and Hamamatsu S10362-33-25c) illuminated with ps laser pulses. The experimental results are in good agreement with the model predictions.
External cueing can improve gait in people with Parkinson's disease (PD), but there is a need for wearable, personalized and flexible cueing techniques that can exploit the power of action-relevant ...visual cues. Augmented Reality (AR) involving headsets or glasses represents a promising technology in those regards. This study examines the gait-modifying effects of real-world and AR cueing in people with PD.
21 people with PD performed walking tasks augmented with either real-world or AR cues, imposing changes in gait speed, step length, crossing step length, and step height. Two different AR headsets, differing in AR field of view (AR-FOV) size, were used to evaluate potential AR-FOV-size effects on the gait-modifying effects of AR cues as well as on the head orientation required for interacting with them.
Participants modified their gait speed, step length, and crossing step length significantly to changes in both real-world and AR cues, with step lengths also being statistically equivalent to those imposed. Due to technical issues, step-height modulation could not be analyzed. AR-FOV size had no significant effect on gait modifications, although small differences in head orientation were observed when interacting with nearby objects between AR headsets.
People with PD can modify their gait to AR cues as effectively as to real-world cues with state-of-the-art AR headsets, for which AR-FOV size is no longer a limiting factor. Future studies are warranted to explore the merit of a library of cue modalities and individually-tailored AR cueing for facilitating gait in real-world environments.
SLR network translations estimated between a quasi‐instantaneous station position set, theoretically expressed with respect to the center of mass of the Earth (CM), and a secular reference frame are ...the signature of the motion of the CM with respect to the Earth crust. Geocenter motion is defined here to be the motion of the CM with respect to the geometric center of the solid Earth surface (CF). SLR translational variations cannot be rigorously interpreted as identical to geocenter motion due to the sparse and nonuniform distribution of the SLR network. Their difference is called the network effect, which should be dominated at subdecadal timescales by loading signals. We have computed translation time series of the SLR network using two independent geophysically based loading models. One is a displacement model estimated from surface fluid data (Green's function approach), called forward model, and the other is a displacement model estimated from GPS and ocean bottom pressure (OBP) data, called inverse model. The translation models have been subtracted from their respective geocenter motion models computed from degree‐1 mass load coefficients in order to evaluate their network effect biases. Scatter due to the SLR network effect is at the level of 1.5 mm RMS. It could slightly shift the phase of the annual SLR geocenter motion estimate by less than 1 month and could affect X and Z annual geocenter motion amplitudes at the 1‐mm level, which is about one third of the expected signal. Two distinct methods are suggested to account for network effect when comparing SLR translations to geocenter motion models. The first is to add the network effect term predicted by a displacement model to the geocenter motion loading model. The second relies on an adequate combination of SLR and GPS products to estimate SLR translation that could be better compared with geocenter motion.
•Anxiety can be characterized by consistently altered intrinsic connectivity between and/or within networks.•Hypo-connectivity of the affective network with executive control network and default mode ...network are associated with anxiety.•Anxiety is associated with consistently attenuated anti-correlations between the executive control network and default mode network.•The connectivity within the salience network as well as its connectivity with sensorimotor network is weakened in anxiety.
Anxiety and anxiety disorders are associated with specific alterations to functional brain networks, including intra-networks and inter-networks. Given the heterogeneity within anxiety disorders and inconsistencies in functional network differences across studies, identifying common patterns of altered brain networks in anxiety is imperative. Here, we conducted an activation likelihood estimation meta-analysis of resting-state functional connectivity studies in anxiety and anxiety disorders (including 835 individuals with different levels of anxiety or anxiety disorders and 508 controls). Results show that anxiety can be characterized by hypo-connectivity of the affective network with executive control network (ECN) and default mode network (DMN), as well as decoupling of the ECN with the DMN. The connectivity within the salience network and its connectivity with sensorimotor network are also attenuated. These results reveal consistent dysregulations of affective and cognitive control related networks over networks related to emotion processing in anxiety and anxiety disorders. The current findings provide an empirical foundation for an integrated model of brain network alterations that are common across anxiety and anxiety disorders.
In response to our article, Davidson and Dahl offer commentary and advice regarding additional topics crucial to a comprehensive prescriptive agenda for future research on mindfulness and meditation. ...Their commentary raises further challenges and provides an important complement to our article. More consideration of these issues is especially welcome because limited space precluded us from addressing all relevant topics. While we agree with many of Davidson and Dahl’s suggestions, the present reply (a) highlights reasons why the concerns we expressed are still especially germane to mindfulness and meditation research (even though those concerns may not be entirely unique) and (b) gives more context to other issues posed by them. We discuss special characteristics of individuals who participate in mindfulness and meditation research and focus on the vulnerability of this field inherent in its relative youthfulness compared to other more mature scientific disciplines. Moreover, our reply highlights the serious consequences of adverse experiences suffered by a significant subset of individuals during mindfulness and other contemplative practices. We also scrutinize common contemporary applications of mindfulness and meditation to illness, and some caveats are introduced regarding mobile technologies for guidance of contemplative practices.
Background
We have observed an increased expression of negative markers in some clinical-grade, xeno- and serum-free cultured adipose-derived mesenchymal stem/stromal cell (ADMSC) samples. It gave ...rise to concern that xeno- and serum-free conditions might have unexpected effects on human ADMSCs. This study aims to test this hypothesis for two xeno- and serum-free media, PowerStem MSC1 media (PS) and StemMACS MSC Expansion Media (SM), that support the in vitro expansion of ADMSCs.
Methods
We investigated the expression of negative markers in 42 clinical-grade ADMSC samples expanded in PS. Next, we cultured ADMSCs from seven donors in PS and SM and examined their growth and colony-forming ability, surface marker expression, differentiation, cell cycle and senescence, as well as genetic stability of two passages representing an early and late passage for therapeutic MSCs.
Results
15 of 42 clinical-grade PS-expanded ADMSC samples showed an increased expression of negative markers ranging from 2.73% to 34.24%, which positively correlated with the age of donors. This rise of negative markers was related to an upregulation of Human Leukocyte Antigen – DR (HLA-DR). In addition, the PS-cultured cells presented decreased growth ability, lower frequencies of cells in S/G2/M phases, and increased ß-galactosidase activity in passage 7 suggesting their senescent feature compared to those grown in SM. Although MSCs of both PS and SM cultures were capable of multilineage differentiation, the PS-cultured cells demonstrated chromosomal abnormalities in passage 7 compared to the normal karyotype of their SM counterparts.
Conclusions
These findings suggest that the SM media is more suitable for the expansion of therapeutic ADMSCs than PS. The study also hints a change of ADMSC features at more advanced passages and with increased donor’s age. Thus, it emphasizes the necessity to cover these aspects in the quality control of therapeutic MSC products.
Graphical abstract
Background
Physical exercise has been shown to reduce anxiety and depression symptoms, the most common mental health disorders globally. Despite the benefits of exercise in anxiety and depression, ...the symptoms of these disorders may directly contribute to a lack of engagement with exercise. However, mental health-related barriers and benefits to exercise engagement have not been addressed in quantitative research. We introduce the development and psychometric validation of the Mental health-related barriers and benefits to EXercise (MEX) scale.
Methods
Three samples were collected online prospectively (sample 1
n
= 492; sample 2
n
= 302; sample 3
n
= 303) for scale refinement and validation with exploratory and confirmatory factor analysis. All participants were generally healthy adults, aged 18–45, and had no history of severe mental illness requiring hospitalization and no physical disability impacting over 50% of daily function.
Results
We identified a 30-item, two-factor model comprising 15 barrier and 15 benefit items. Overall model fit was excellent for an item-level scale across the three samples (Comparative Fit Index = 0.935–0.951; Root-Mean-Square Error of Approximation = 0.037–0.039). Internal consistency was also excellent across the three samples (
α
= 0.900–0.951). The barriers subscale was positively correlated with symptoms of anxiety, depression and stress, and negatively correlated with measures of physical activity and exercise engagement. The benefits subscale was negatively correlated with symptoms of anxiety, depression and stress, and positively correlated with measures of physical activity and exercise engagement.
Conclusion
The MEX is a novel, psychometrically robust scale, which is appropriate for research and for clinical use to ascertain individual and/or group level mental health-related barriers and benefits to exercise.
The COVID-19 pandemic caused a surge in the use of telehealth platforms. Psychologists have shifted from face-to-face sessions to videoconference sessions. Therefore, essential information that is ...easily obtainable via in-person sessions may be missing. Consequently, therapeutic work could be compromised.
This study aimed to explore the videoconference psychotherapy (VCP) experiences of psychologists around the world. Furthermore, we aimed to identify technological features that may enhance psychologists' therapeutic work through augmented VCP.
In total, 17 psychologists across the world (n=7, 41% from Australia; n=1, 6% from England; n=5, 29% from Italy; n=1, 6% from Mexico; n=1, 6% from Spain; and n=2, 12% from the United States) were interviewed. We used thematic analysis to examine the data collected from a sample of 17 psychologists. We applied the Chaos Theory to interpret the system dynamics and collected details about the challenges posed by VCP. For collecting further information about the technology and processes involved, we relied on the Input-Process-Output (IPO) model.
The analysis resulted in the generation of 9 themes (input themes: psychologists' attitude, trust-reinforcing features, reducing cognitive load, enhancing emotional communication, and engaging features between psychologists and patients; process themes: building and reinforcing trust, decreasing cognitive load, enhancing emotional communication, and increasing psychologist-patient engagement) and 19 subthemes. Psychologists found new strategies to deal with VCP limitations but also reported the need for more technical control to facilitate therapeutic processes. The suggested technologies (eye contact functionality, emergency call functionality, screen control functionality, interactive interface with other apps and software, and zooming in and out functionality) could enhance the presence and dynamic nature of the therapeutic relationship.
Psychologists expressed a desire for enhanced control of VCP sessions. Psychologists reported a decreased sense of control within the therapeutic relationship owing to the influence of the VCP system. Great control of the VCP system could better approximate the critical elements of in-person psychotherapy (eg, observation of body language). To facilitate improved control, psychologists would like technology to implement features such as improved eye contact, better screen control, emergency call functionality, ability to zoom in and out, and an interactive interface to communicate with other apps. These results contribute to the general perception of the computer as an actual part of the VCP process. Thus, the computer plays a key role in the communication, rather than remaining as a technical medium. By adopting the IPO model in the VCP environment (VCP-IPO model), the relationship experience may help psychologists have more control in their VCP sessions.
PDF
