2,754 research outputs found
Counting Triangulations and other Crossing-Free Structures Approximately
We consider the problem of counting straight-edge triangulations of a given
set of points in the plane. Until very recently it was not known
whether the exact number of triangulations of can be computed
asymptotically faster than by enumerating all triangulations. We now know that
the number of triangulations of can be computed in time,
which is less than the lower bound of on the number of
triangulations of any point set. In this paper we address the question of
whether one can approximately count triangulations in sub-exponential time. We
present an algorithm with sub-exponential running time and sub-exponential
approximation ratio, that is, denoting by the output of our
algorithm, and by the exact number of triangulations of , for some
positive constant , we prove that . This is the first algorithm that in sub-exponential time computes a
-approximation of the base of the number of triangulations, more
precisely, . Our algorithm can be
adapted to approximately count other crossing-free structures on , keeping
the quality of approximation and running time intact. In this paper we show how
to do this for matchings and spanning trees.Comment: 19 pages, 2 figures. A preliminary version appeared at CCCG 201
Design and material evaluation for a novel lumbar disc replacement implanted via unilateral transforaminal approach
Medication adherence and activity patterns underlying uncontrolled hypertension: Assessment and recommendations by practicing pharmacists using digital health care
AbstractObjectivesThis report summarizes the first use of a digital health feedback system (DHFS) by practicing pharmacists to establish evidence-based blood pressure (BP) management recommendations.SettingFifteen commercial pharmacies and 39 patients in the Isle of Wight participated.Practice descriptionThe pharmacists were experienced in providing New Medicine Services to patients in their communities.Practice innovationThe pharmacists utilized a commercially available DHFS. The DHFS utilized FDA-cleared and CE-marked class 2 medical devices passively captured and shared information about medication-taking using an ingestible sensor, and daily patterns of rest, activity, and exercise using a wearable patch that incorporates an accelerometer.InterventionsPharmacists provided targeted counselling for BP management as guided by the digital information.EvaluationBlood pressure was measured serially, and patient and provider experiences with DHFS use were assessed using satisfaction surveys.ResultsThe mean change in SBP over the 2-week evaluation period was -7.9 ± 22.1; mean change in DBP was -2.8 ± 12.9. A root cause for persistent hypertension was determined for all of these 34 patients: 68% had pharmaceutical resistance, and 32% had inadequate medication use. Specifically, 29% were found to be capable to achieving blood pressure control on their currently prescribed medications, 68% were found to have a need for additional pharmacological treatment, and 3% needed additional adherence support. Pharmacists found that the DHFD helped in targeting specific recommendations, and to create a collaborative experience with their patients. Patients found the experience to be positive and helpful.ConclusionDHFS that provides confirmation of medication taking and objective measures of lifestyle patterns can help pharmacists to identify specific factors contributing to uncontrolled hypertension, to make evidence-based prescribing and lifestyle recommendations for achieving treatment goals, and to create a collaborative experience for patients in the management of their self-care
The need for geospatial thinking in education : a manual for implementing geospatial thinking competencies in the curriculum
B
Design and mechanical evaluation of a novel dynamic growing rod to improve the surgical treatment of Early Onset Scoliosis
Circuit mechanisms for the chemical modulation of cortex-wide network interactions and behavioral variability
Influential theories postulate distinct roles of catecholamines and acetylcholine in cognition and behavior. However, previous physiological work reported similar effects of these neuromodulators on the response properties (specifically, the gain) of individual cortical neurons. Here, we show a double dissociation between the effects of catecholamines and acetylcholine at the level of large-scale interactions between cortical areas in humans. A pharmacological boost of catecholamine levels increased cortex-wide interactions during a visual task, but not rest. An acetylcholine boost decreased interactions during rest, but not task. Cortical circuit modeling explained this dissociation by differential changes in two circuit properties: the local excitation-inhibition balance (more strongly increased by catecholamines) and intracortical transmission (more strongly reduced by acetylcholine). The inferred catecholaminergic mechanism also predicted noisier decision-making, which we confirmed for both perceptual and value-based choice behavior. Our work highlights specific circuit mechanisms for shaping cortical network interactions and behavioral variability by key neuromodulatory systems
Making Neural Networks Interpretable with Attribution: Application to Implicit Signals Prediction
Explaining recommendations enables users to understand whether recommended
items are relevant to their needs and has been shown to increase their trust in
the system. More generally, if designing explainable machine learning models is
key to check the sanity and robustness of a decision process and improve their
efficiency, it however remains a challenge for complex architectures,
especially deep neural networks that are often deemed "black-box". In this
paper, we propose a novel formulation of interpretable deep neural networks for
the attribution task. Differently to popular post-hoc methods, our approach is
interpretable by design. Using masked weights, hidden features can be deeply
attributed, split into several input-restricted sub-networks and trained as a
boosted mixture of experts. Experimental results on synthetic data and
real-world recommendation tasks demonstrate that our method enables to build
models achieving close predictive performances to their non-interpretable
counterparts, while providing informative attribution interpretations.Comment: 14th ACM Conference on Recommender Systems (RecSys '20
Deletion of cytosolic gating ring decreases gate and voltage sensor coupling in BK channels
Large conductance Ca(2+)-activated K(+) channels (BK channels) gate open in response to both membrane voltage and intracellular Ca(2+). The channel is formed by a central pore-gate domain (PGD), which spans the membrane, plus transmembrane voltage sensors and a cytoplasmic gating ring that acts as a Ca(2+) sensor. How these voltage and Ca(2+) sensors influence the common activation gate, and interact with each other, is unclear. A previous study showed that a BK channel core lacking the entire cytoplasmic gating ring (Core-MT) was devoid of Ca(2+) activation but retained voltage sensitivity (Budelli et al. 2013. Proc. Natl. Acad. Sci. USA. http://dx.doi.org/10.1073/pnas.1313433110). In this study, we measure voltage sensor activation and pore opening in this Core-MT channel over a wide range of voltages. We record gating currents and find that voltage sensor activation in this truncated channel is similar to WT but that the coupling between voltage sensor activation and gating of the pore is reduced. These results suggest that the gating ring, in addition to being the Ca(2+) sensor, enhances the effective coupling between voltage sensors and the PGD. We also find that removal of the gating ring alters modulation of the channels by the BK channelâs ÎČ1 and ÎČ2 subunits
Measurements of the Cosmic Ray Composition with Air Shower Experiments
In this paper we review air shower data related to the mass composition of
cosmic rays above 10 eV. After explaining the basic relations between
air shower observables and the primary mass and energy of cosmic rays, we
present different approaches and results of composition studies with surface
detectors. Furthermore, we discuss measurements of the longitudinal development
of air showers from non-imaging Cherenkov detectors and fluorescence
telescopes. The interpretation of these experimental results in terms of
primary mass is highly susceptible to the theoretical uncertainties of hadronic
interactions in air showers. We nevertheless attempt to calculate the
logarithmic mass from the data using different hadronic interaction models and
to study its energy dependence from 10 to 10 eV.Comment: 21 pages, invited review accepted for publication in Astroparticle
Physics, Topical Issue on Cosmic Ray
MITF and TFEB cross-regulation in melanoma cells
Publisher's version (Ăștgefin grein)The MITF, TFEB, TFE3 and TFEC (MiT-TFE) proteins belong to the basic helix-loop-helix family of leucine zipper transcription factors. MITF is crucial for melanocyte development and differentiation, and has been termed a lineage-specific oncogene in melanoma. The three related proteins MITF, TFEB and TFE3 have been shown to be involved in the biogenesis and function of lysosomes and autophagosomes, regulating cellular clearance pathways. Here we investigated the cross-regulatory relationship of MITF and TFEB in melanoma cells. Like MITF, the TFEB and TFE3 genes are expressed in melanoma cells as well as in melanoma tumors, albeit at lower levels. We show that the MITF and TFEB proteins, but not TFE3, directly affect each otherâs mRNA and protein expression. In addition, the subcellular localization of MITF and TFEB is subject to regulation by the mTOR signaling pathway, which impacts their cross-regulatory relationship at the transcriptional level. Our work shows that the relationship between MITF and TFEB is multifaceted and that the cross-regulatory interactions of these factors need to be taken into account when considering pathways regulated by these proteins.ES, 130230-052, Research fund of Iceland, www.rannis.is ES, 163413-051, Research fund of Iceland, www.rannis.is.Peer Reviewe
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