12,431 research outputs found
Learning Points and Routes to Recommend Trajectories
The problem of recommending tours to travellers is an important and broadly
studied area. Suggested solutions include various approaches of
points-of-interest (POI) recommendation and route planning. We consider the
task of recommending a sequence of POIs, that simultaneously uses information
about POIs and routes. Our approach unifies the treatment of various sources of
information by representing them as features in machine learning algorithms,
enabling us to learn from past behaviour. Information about POIs are used to
learn a POI ranking model that accounts for the start and end points of tours.
Data about previous trajectories are used for learning transition patterns
between POIs that enable us to recommend probable routes. In addition, a
probabilistic model is proposed to combine the results of POI ranking and the
POI to POI transitions. We propose a new F score on pairs of POIs that
capture the order of visits. Empirical results show that our approach improves
on recent methods, and demonstrate that combining points and routes enables
better trajectory recommendations
Submillimeter Array multiline observations of the massive star-forming region IRAS 18089-1732
Submillimeter Array (SMA) observations of the high-mass star-forming region
IRAS 18089-1732 in the 1 mm and 850 m band with 1 GHz bandwidth reveal a
wealth of information. We present the observations of 34 lines from 16
different molecular species. Most molecular line maps show significant
contributions from the outflow, and only few molecules are confined to the
inner core. We present and discuss the molecular line observations and outline
the unique capabilities of the SMA for future imaging line surveys at high
spatial resolution.Comment: Accepted for ApJ Letters, SMA special volum
SMA outflow/disk studies in the massive star-forming region IRAS18089-1732
SMA observations of the massive star-forming region IRAS 18089-1732 in the
1mm and 850mu band reveal outflow and disk signatures in different molecular
lines. The SiO(5--4) data show a collimated outflow in the northern direction.
In contrast, the HCOOCH3(20--19) line, which traces high-density gas, is
confined to the very center of the region and shows a velocity gradient across
the core. The HCOOCH3 velocity gradient is not exactly perpendicular to the
outflow axis but between an assumed disk plane and the outflow axis. We
interpret these HCOOCH3 features as originating from a rotating disk that is
influenced by the outflow and infall. Based on the (sub-)mm continuum emission,
the mass of the central core is estimated to be around 38M_sun. The dynamical
mass derived from the HCOOCH3 data is 22Msun, of about the same order as the
core mass. Thus, the mass of the protostar/disk/envelope system is dominated by
its disk and envelope. The two frequency continuum data of the core indicate a
low dust opacity index beta ~ 1.2 in the outer part, decreasing to beta ~ 0.5
on shorter spatial scales.Comment: 7 pages of text, 1 table, 3 figures, accepted for ApJ Letter
The global burden of plastics in oral health: prospects for circularity, sustainable materials development and practice
Plastics are indispensable and ubiquitous materials in oral healthcare and dental applications, favored for their diversity in structure and properties, low cost, durability, chemical and water resistance, ease of processing, and shaping. However, ancillary plastics are used for short periods or even once due to hygiene concerns and convenience, and insufficient attention has been given to their unsustainable current usage and end-of-life. Thus, the amount of plastic waste generated by consumers and clinicians is staggering and projected to increase unabatedly for the foreseeable future. With recent advances in plastics recycling and sustainable polymers, it is time to consider alternatives to tackle dentistry's growing plastic waste problem. This Perspectives article highlights the sources and scale of dental plastic wastage, followed by a multi-pronged consideration of material and practical interventions for this issue. On the materials front, we discuss emerging approaches and alternative sustainable polymers to address the unsustainable end-of-life of existing petroleum-based dental plastics/polymers and enable material circularity. On the practical front, we discuss strategies for sustainable plastic usage, which must be implemented alongside complementary material approaches. These approaches highlight the abundant unrealized opportunities for developing a circular economy around dental plastics while reducing the environmental footprint of modern dentistr
The use of importance-performance analysis approach in evaluating Penang National Park
Penang National Park has been listed as one of the eco-tourism destination in Malaysia. In tourism
management, importance-performance analysis (IPA) has been used as part of quality management. The objective of this research paper was to use importance–performance analysis (IPA) to examine the performance of Penang National Park. A quantitative questionnaire was distributed to 385 tourists at the Penang National Park by using the convenience sampling approach.The respondents were provided with a list of environmental and social attributes and asked to rate the importance and performance of each attribute.The IPA grid is broken into four categories: (1) Concentrate Here; (2) Keep Up the Good Work; (3) Low Priority; and (4) Possible Overkill, to enable each of the attributes to be plotted into the grid. It is a clear and powerful evaluation tool for management to find out attributes that are doing well and attributes that need to be improved, which require action immediately.The results of IPA identified that factor 2 (Scenery and comfort) and factor 4 (Environment) are attributes that have high importance and performance.The attribute
that need to be improved was identified as factor 3 (Safety), suggesting management attention is needed.The results of the study can be used by management in Penang National Park to improve the attributes that tourists think are most important. Other tourist destinations could also conduct similar studies to examine their performance
Amplification of 12 OAM states in an air-core EDF
We propose the amplification of 12 OAM modes in an air-core EDF using either core- or cladding- pumping at 980nm. Differential modal gains of only 0.25dB among all the 12-modes are achieved over the C-band
BatMeth: improved mapper for bisulfite sequencing reads on DNA methylation
10.1186/gb-2012-13-10-R82Genome Biology1310-GNBL
Cyclic cosmology from Lagrange-multiplier modified gravity
We investigate cyclic and singularity-free evolutions in a universe governed
by Lagrange-multiplier modified gravity, either in scalar-field cosmology, as
well as in one. In the scalar case, cyclicity can be induced by a
suitably reconstructed simple potential, and the matter content of the universe
can be successfully incorporated. In the case of -gravity, cyclicity can
be induced by a suitable reconstructed second function of a very
simple form, however the matter evolution cannot be analytically handled.
Furthermore, we study the evolution of cosmological perturbations for the two
scenarios. For the scalar case the system possesses no wavelike modes due to a
dust-like sound speed, while for the case there exist an oscillation
mode of perturbations which indicates a dynamical degree of freedom. Both
scenarios allow for stable parameter spaces of cosmological perturbations
through the bouncing point.Comment: 8 pages, 3 figures, references added, accepted for publicatio
Potassium channel dysfunction in human neuronal models of Angelman syndrome
Disruptions in the ubiquitin protein ligase E3A (UBE3A) gene cause Angelman syndrome (AS). Whereas AS model mice have associated synaptic dysfunction and altered plasticity with abnormal behavior, whether similar or other mechanisms contribute to network hyperactivity and epilepsy susceptibility in AS patients remains unclear. Using human neurons and brain organoids, we demonstrate that UBE3A suppresses neuronal hyperexcitability via ubiquitin-mediated degradation of calcium- and voltage-dependent big potassium (BK) channels. We provide evidence that augmented BK channel activity manifests as increased intrinsic excitability in individual neurons and subsequent network synchronization. BK antagonists normalized neuronal excitability in both human and mouse neurons and ameliorated seizure susceptibility in an AS mouse model. Our findings suggest that BK channelopathy underlies epilepsy in AS and support the use of human cells to model human developmental diseases
- …