A flexible and optimal approach for appointment scheduling in healthcare

Appointment scheduling is generally applied in outpatient clinics and other healthcare services. The challenge in scheduling is to find a strategy for dealing with variability and unpredictability in service duration and patient arrivals. The consequences of an ineffective strategy include long waiting times for patients and idle time for the healthcare provider. In turn, these have implications for the perceived quality, cost-efficiency, and capacity of healthcare services. The generation of optimal schedules is a notoriously intractable problem, and earlier attempts at designing effective strategies for appointment scheduling were based on approximation, simulation, or simplification. We propose a novel strategy for scheduling that exploits three tactical ideas to make the problem manageable. We compare the proposed strategy to other approaches, and show that it matches or outperforms competing methods in terms of flexibility, ease of use, and speed. More importantly, it outperforms competing approaches nearly uniformly in approaching the desired balance between waiting and idle times as specified in a chosen objective function. Therefore, the strategy is a good basis for further enrichments

A Project Based Approach to Statistics and Data Science

In an increasingly data-driven world, facility with statistics is more important than ever for our students. At institutions without a statistician, it often falls to the mathematics faculty to teach statistics courses. This paper presents a model that a mathematician asked to teach statistics can follow. This model entails connecting with faculty from numerous departments on campus to develop a list of topics, building a repository of real-world datasets from these faculty, and creating projects where students interface with these datasets to write lab reports aimed at consumers of statistics in other disciplines. The end result is students who are well prepared for interdisciplinary research, who are accustomed to coping with the idiosyncrasies of real data, and who have sharpened their technical writing and speaking skills

The host galaxy of the z=2.4 radio-loud AGN MRC 0406-244 as seen by HST

We present multicolour Hubble Space Telescope images of the powerful z=2.4 radio galaxy MRC 0406-244 and model its complex morphology with several components including a host galaxy, a point source, and extended nebular and continuum emission. We suggest that the main progenitor of this radio galaxy was a normal, albeit massive (M ~10^{11} solar masses), star-forming galaxy. The optical stellar disc of the host galaxy is smooth and well described by a S\'ersic profile, which argues against a recent major merger, however there is also a point-source component which may be the remnant of a minor merger. The half-light radius of the optical disc is constrained to lie in the range 3.5 to 8.2kpc, which is of similar size to coeval star forming galaxies. Biconical shells of nebular emission and UV-bright continuum extend out from the host galaxy along the radio jet axis, which is also the minor axis of the host galaxy. The origin of the continuum emission is uncertain, but it is most likely to be young stars or dust-scattered light from the AGN, and it is possible that stars are forming from this material at a rate of 200^{+1420}_{-110} solar masses per year.Comment: Accepted for publication in MNRA

Toxicity Profiles In Vivo in Mice and Antitumour Activity in Tumour-Bearing Mice of Di- and Triorganotin Compounds

The in vivo toxicity profiles in mice and the antitumour activity in tumour bearing mice were screened for four di-n-butyltin and five triorganotin carboxylates, di-n-butyltin diterebate (5), bis(phenylacetate) (6), bis(deoxycholate) (7), bis(lithocholate) (8), tri-n-butyltin terebate (9), cinnamate (10), and triphenyltin terebate (11)

Using a composite flow law to model deformation in the NEEM deep ice core, Greenland — Part 2: The role of grain size and premelting on ice deformation at high homologous temperature

The ice microstructure in the lower part of the North Greenland Eemian Ice Drilling (NEEM) ice core consists of relatively fine-grained ice with a single maximum crystallographic preferred orientation (CPO) alternated by much coarser-grained ice with a partial (great circle) girdle or multi-maxima CPO. In this study, the grain-size-sensitive (GSS) composite flow law of Goldsby and Kohlstedt (2001) was used to study the effects of grain size and premelting (liquid-like layer along the grain boundaries) on strain rate in the lower part of the NEEM ice core. The results show that the strain rates predicted in the fine-grained layers are about an order of magnitude higher than in the much coarser-grained layers. The dominant deformation mechanisms, based on the flow relation of Goldsby and Kohlstedt (2001), between the layers is also different, with basal slip rate limited by grain boundary sliding (GBS-limited creep) being the dominant deformation mechanism in the finer-grained layers, while GBS-limited creep and dislocation creep (basal slip rate limited by non-basal slip) contribute both roughly equally to bulk strain in the coarse-grained layers. Due to the large difference in microstructure between finer-grained ice and the coarse-grained ice at premelting temperatures (T>262 K), it is expected that the fine-grained layers deform at high strain rates, while the coarse-grained layers are relatively stagnant. The difference in microstructure, and consequently in viscosity, between impurity-rich and low-impurity ice can have important consequences for ice dynamics close to the bedrock

Gamma‐ray burst studies by COMPTEL during its first year of operation

During the first year of Compton GRO operations, more than 20 cosmic gamma‐ray burst‐detected by the BATSE instrument ‐ occurred inside the 1 sr field of view of the imaging gamma‐ray telescope COMPTEL. Using COMPTEL’s primary mode of operation (the telescope mode) direct images (with ∼1° GRB location accuracy) and event spectra (0.7 MeV – 30 MeV) with spectral resolution better than 10% FWHM have been obtained. In its secondary mode of burst operations, COMPTEL has recorded time resolved spectra (0.1 MeV – 10 MeV) from its large NaI detectors. This paper summarises the results on cosmic GRB sources obtained by COMPTEL during its first year of operation

Watergeeffrequentie en substraatsystemen bij Bouvardia

Van maart 1988 tot januari '89 is een proef uitgevoerd met als proeffactoren substraatsystemen (steenwol ingeluierd, steenwol afgedekt, steenwol kaal) en watergeeffrequenties (laag, middel, hoog