Accelerated Parallel Non-conjugate Sampling for Bayesian Non-parametric Models

Inference of latent feature models in the Bayesian nonparametric setting is generally difficult, especially in high dimensional settings, because it usually requires proposing features from some prior distribution. In special cases, where the integration is tractable, we could sample new feature assignments according to a predictive likelihood. However, this still may not be efficient in high dimensions. We present a novel method to accelerate the mixing of latent variable model inference by proposing feature locations from the data, as opposed to the prior. First, we introduce our accelerated feature proposal mechanism that we will show is a valid Bayesian inference algorithm and next we propose an approximate inference strategy to perform accelerated inference in parallel. This sampling method is efficient for proper mixing of the Markov chain Monte Carlo sampler, computationally attractive, and is theoretically guaranteed to converge to the posterior distribution as its limiting distribution.Comment: Previously known as "Accelerated Inference for Latent Variable Models

Extracellular ATP triggers proteolysis and cytosolic Ca²⁺ rise in Plasmodium berghei and Plasmodium yoelii malaria parasites.

BACKGROUND: Plasmodium has a complex cell biology and it is essential to dissect the cell-signalling pathways underlying its survival within the host. METHODS: Using the fluorescence resonance energy transfer (FRET) peptide substrate Abz-AIKFFARQ-EDDnp and Fluo4/AM, the effects of extracellular ATP on triggering proteolysis and Ca²⁺ signalling in Plasmodium berghei and Plasmodium yoelii malaria parasites were investigated. RESULTS: The protease activity was blocked in the presence of the purinergic receptor blockers suramin (50 μM) and PPADS (50 μM) or the extracellular and intracellular calcium chelators EGTA (5 mM) and BAPTA/AM (25, 100, 200 and 500 μM), respectively for P. yoelii and P. berghei. Addition of ATP (50, 70, 200 and 250 μM) to isolated parasites previously loaded with Fluo4/AM in a Ca²⁺-containing medium led to an increase in cytosolic calcium. This rise was blocked by pre-incubating the parasites with either purinergic antagonists PPADS (50 μM), TNP-ATP (50 μM) or the purinergic blockers KN-62 (10 μM) and Ip5I (10 μM). Incubating P. berghei infected cells with KN-62 (200 μM) resulted in a changed profile of merozoite surface protein 1 (MSP1) processing as revealed by western blot assays. Moreover incubating P. berghei for 17 h with KN-62 (10 μM) led to an increase in rings forms (82% ± 4, n = 11) and a decrease in trophozoite forms (18% ± 4, n = 11). CONCLUSIONS: The data clearly show that purinergic signalling modulates P. berghei protease(s) activity and that MSP1 is one target in this pathway

The Brown Dwarf Kinematics Project (BDKP). II. Details on Nine Wide Common Proper Motion Very Low-Mass Companions to Nearby Stars

We report on nine wide common proper motion systems containing late-type M, L, or T companions. We confirm six previously reported companions, and identify three new systems. The ages of these systems are determined using diagnostics for both stellar primaries and low--mass secondaries and masses for the secondaries are inferred using evolutionary models. Of our three new discoveries, the M3+T6.5 pair G 204-39 and SDSS J1758+4633 has an age constrained to 0.5-1.5 Gyr making the secondary a potentially useful brown dwarf benchmark. The G5+L4 pair G 200-28 and SDSS J1416+5006 has a projected separation of ~25,000 AU making it one of the widest and lowest binding energy systems known to date. The system containing NLTT 2274 and SDSS J0041+1341 is an older M4+L0 (>4.5 Gyr) pair which shows Halpha activity in the secondary but not the primary making it a useful tracer of age/mass/activity trends. We find a resolved binary frequency for widely-separated (> 100 AU) low--mass companions (i.e. at least a triple system) which is at least twice the frequency found for the field ultracool dwarf population. The ratio of triples to binaries and quadruples to binaries is also high for this sample: 3:5 and 1:4, respectively, compared to 8-parsec sample values of 1:4 and 1:26. The additional components in these wide companion systems indicates a formation mechanism that requires a third or fourth component to maintain gravitational stability or facilitate the exchange of angular momentum. The binding energies for the nine multiples discussed in this text are among the lowest known for wide low-mass systems, suggesting that weakly bound, low--to--intermediate mass (0.2M_sun < M_tot <1.0M_sun) multiples can form and survive to exist in the field (1-8 Gyr).Comment: 62 pages, 12 figures, 11 Tables, AJ accepted for publicatio

Is there a link between overactive bladder and the metabolic syndrome in women? : A systematic review of observational studies

This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.To conduct a systematic review to determine whether there is an association between metabolic syndrome (MetS) and lower urinary tract symptoms (LUTS) or overactive bladder (OAB) in women. We systematically reviewed English language observational studies on the effect of MetS (or component factors) on the presence of OAB or LUTS in women. We searched PubMed, Web of Science and The Cochrane Library with no date restrictions, checked reference lists and undertook citation searches in PubMed and Google Scholar. Studies were assessed for risk of bias. Because of heterogeneity, results were not pooled, but are reported narrativelyPeer reviewe

Comparing In-The-Moment Skill Coaching Effects from Tailored Versus Non-Tailored Acceptance and Commitment Therapy Mobile Apps in a Non-Clinical Sample

Mobile apps are promising for teaching how to practice psychological skills in high-risk and in vivo momentary situations, but there has been minimal research on the immediate effects of app-based skill coaching on mental health in-the-moment. This study analyzed the mobile app data in a non-clinical sample of 39 adults participating in a larger randomized controlled trial, with participants randomized to an acceptance and commitment therapy (ACT) mobile app that tailors skill coaching based on in-the-moment variables (n = 17) or an app that provides randomly selected skill coaching (n = 22). Data was collected before and after each ACT skill coaching session on proximal outcome (depression, anxiety, engagement in meaningful activity) and ACT process variables. Multilevel models indicated significant immediate improvements on average following ACT skill coaching sessions on all proximal outcome and ACT process variables, although with relatively small effects ranging between .17 and .27 SD units change. Larger immediate pre-to- post effects from ACT coaching sessions were found for anxiety, experiential avoidance, and cognitive fusion in the tailored app versus random app condition. Overall, results suggest an ACT app can have immediate, in-the-moment effects on psychological functioning, which may be enhanced by tailoring skills to current context

An Ecological Momentary Assessment Study Investigating the Function of Hoarding

This study examined the function of hoarding behaviors and the relations between hoarding and a series of cognitive and affective processes in the moment using ecological momentary assessment. A matched-groups design was used to compare college students with higher hoarding symptoms (n = 31) and matched controls (n = 29). The two groups did not differ in what function they reported acquiring served, and positive automatic reinforcement was the most commonly reported function in both groups. Engaging in hoarding-relevant behaviors did not predict change in positive or negative affect when controlling for previous affect. Emotional reactivity and experiential avoidance in the moment were both elevated in the higher hoarding group compared to controls, while momentary mindfulness and negative affect differentiation were lower. Overall, these findings support the importance of emotion regulation processes in hoarding. They also suggest individuals may not be successfully regulating affect in the moment with hoarding behaviors, despite efforts to do so. It may be useful to evaluate processes such as striving for positive affect in hoarding disorder in the future

Evaluating an adjunctive mobile app to enhance psychological flexibility in acceptance and commitment therapy

The primary aims of this study were to evaluate the feasibility and potential efficacy of a novel adjunctive mobile app designed to enhance the acquisition, strengthening, and generalization of acceptance and commitment therapy (ACT) skills being taught in therapy. A sample of 14 depressed/anxious clients receiving ACT used the ACT Daily app for two weeks in a pre-post, open trial design. Participants reported a high degree of program satisfaction. Clients significantly improved over the two-week period on depression and anxiety symptoms as well as a range of psychological inflexibility measures. Analyses of mobile app data indicated effects of ACT Daily skill coaching on in-the-moment measures of inflexibility and symptoms, with unique effects found for acceptance and mindfulness. Adjunctive ACT mobile apps appear promising in enhancing therapy effects on psychological inflexibility and outcomes. A tailored skill coaching approach like ACT Daily based on randomly prompted assessments may be especially promising

The Brown Dwarf Kinematics Project (BDKP). III. Parallaxes for 70 Ultracool Dwarfs

We report parallax measurements for 70 ultracool dwarfs (UCDs). Using both literature values and our sample, we report new polynomial relations between spectral type and M$_{JHK}$. Including resolved L/T transition binaries in the relations, we find no reason to differentiate between a "bright" (unresolved binary) and "faint" (single source) sample across the L/T boundary. Isolating early T dwarfs, we find that the brightening of T0-T4 sources is prominent in M$_{J}$ where there is a [1.2 - 1.4] magnitude difference. A similar yet dampened brightening of [0.3 - 0.5] magnitude happens at M$_{H}$ and a plateau or dimming of [-0.2 - -0.3] magnitude is seen in M$_{K}$. Comparing with evolutionary models that vary gravity, metallicity, and cloud thickness we find that a near constant temperature of 1200 $\pm$100 K along a narrow spectral subtype of T0-T4 is required to account for the brightening and color magnitude diagram of the L-dwarf/T-dwarf transition. Furthermore, there is a significant population of both L and T dwarfs which are red or potentially "ultra-cloudy" compared to the models, many of which are known to be young indicating a correlation between enhanced photospheric dust and youth. For the low surface-gravity or young companion L dwarfs we find that 8 out of 10 are at least [0.2-1.0] magnitude underluminous in M$_{JH}$ and/or M$_{K}$ compared to equivalent spectral type objects. We speculate that this is a consequence of increased dust opacity and conclude that low-surface gravity L dwarfs require a completely new spectral-type/absolute magnitude polynomial for analysis.Comment: 65 pages, Accepted for publication to Ap