A probabilistic patient scheduling model for reducing the number of no-shows

No-shows in medical centres cause under-utilisation of resources and increase waiting times in specialty health care services. Although this problem has been addressed in literature, behavioural issues associated with the patient's socio-demographic characteristics and diagnosis have not been widely studied. In this article, we propose a model that includes such behavioural issues in order to reduce impact of no-shows in medical services. The objective is maximising the health centre's expected revenue by using show-up probabilities estimated for each combination of patient and appointment slot. Additionally, the model considers the requirements imposed by both the health centre's management and the health authorities. An extension of the model allows overbooking in some appointment slots. Experimental results show that the proposed model can reduce the waiting list length by 13%, and to attain an increase of about 5% in revenue, when comparing to a model that assigns patients to the first available slot

Computerized adaptive test and decision trees: A unifying approach

In the last few years, several articles have proposed decision trees (DTs) as an alternative to computerized adapted tests (CATs). These works have focused on showing the differences between the two methods with the aim of identifying the advantages of each of them and thus determining when it is preferable to use one method or another. In this article, Tree-CAT, a new technique for building CATs is presented. Unlike the existing work, Tree-CAT exploits the similarities between CATs and DTs. This technique allows the creation of CATs that minimise the mean square error in the estimation of the examinee’s ability level, and controls the item’s exposure rate. The decision tree is sequentially built by means of an innovative algorithmic procedure that selects the items associated with each of the tree branches by solving a linear program. In addition, our work presents further advantages over alternative item selection techniques with exposure control, such as instant item selection or simultaneous administration of the test to an unlimited number of participants. These advantages allow accurate on-line CATs to be implemented even when the item selection method is computationally costly

Effect of Defoliation Frequency and Planting Density on Yield and Nutritive Value of \u3ci\u3eCoursetia ferruginea\u3c/i\u3e (HBK) Lavin

The aim of the present study was to asses the influence of the frequency of defoliation and density of sowing on yield and nutritive value of Coursetia ferruginea. Three defoliation frequencies (6, 8 and 10 weeks) and three densities of planting (1 x 1 m, 1 x 1.5 m and 1 x 2 m) were evaluated. A randomized block design, in a split plot arrangement and four repetitions, was used. Frequency of defoliation has a strong significant (P\u3c 0.01) effect on dry matter (DM) yield (13.6, 18.1 and 27.8 g DM/plant for 6, 8 and 10-week defoliation frequencies), plant height (63.5, 76.6 and 101.2 cm) and plant survival (71, 74 and 86%). Nutritive value was significantly (P\u3c 0.05) affected by the frequency of defoliation. Mineral content was reduced as the defoliation interval increased. Density of planting did not affect (P\u3e 0.05) any of the variables. It is concluded that, C. ferruginea is a forage shrub with potential to improve animal feed quality, but it does not stand frequent defoliation

Multi-machine preventive maintenance scheduling with imperfect interventions: A restless bandit approach

In this paper we address the problem of allocating the efforts of a collection of repairmen to a number of deteriorating machines in order to reduce operation costs and to mitigate the cost (and likelihood) of unexpected failures. Notwithstanding these preventive maintenance interventions are aimed at returning the machine to a so-called as-good-as-new state, unforeseeable factors may imply that maintenance interventions are not perfect and the machine is only returned to an earlier (uncertain) state of wear. The problem is modelled as a restless bandit problem and an index policy for the sequential allocation of maintenance tasks is proposed. A series of numerical experiments shows the strong performance of the proposed policy. Moreover, the methodology is of interest in the general context of dynamic resource allocation and restless bandit problems, as well as being useful in the particular imperfect maintenance model described

Addressing potential sources of variation in several non-destructive techniques for measuring firmness in apples

Measurements of firmness have traditionally been carried out according to the Magness Taylor (MT) procedure; using a texture analyser or penetrometer in reference texture tests. Non-destructive tests like the acoustic impulse response of acoustic firmness sensors (AFSs), a low-mass impact firmness sensor Sinclair International (SIQ-FT) and impact test (Lateral Impact – UPM) have also been used to measure texture and firmness. The objectives of this study were to evaluate the influence of different sources of variation in these three non-destructive tests and to evaluate their respective capabilities of discriminating between fruit maturity at two different harvest dates, turgidity before and after dehydration treatment and ripening after different storage periods. According to our results, fruit studied an unexpected AFS trend with turgidity. Contact measurements (Lateral Impact – UPM and SIQ-FT) appeared highly sensitive to changes in turgidity, but were less able to follow changes in ripening caused by storage period. Contact measurements were suitable for detecting differences between fruits from different harvest dates and showed higher correlation coefficients with reference texture tests than acoustic measurements. The Lateral Impact – UPM test proved better at separating fruits according to turgidity than the SIQ-FT instrumen

Variable order Mittag-Leffler fractional operators on isolated time scales and application to the calculus of variations

We introduce new fractional operators of variable order on isolated time scales with Mittag-Leffler kernels. This allows a general formulation of a class of fractional variational problems involving variable-order difference operators. Main results give fractional integration by parts formulas and necessary optimality conditions of Euler-Lagrange type.Comment: This is a preprint of a paper whose final and definite form is with Springe

Reparación de las fracturas de huesos largos en traumatismos craneoencefálicos: estudio experimental en la rata

Los pacientes con traumatismo craneoencefálico presentan una respuesta osteogénica alterada. Para estudiar si existe o no un callo de fractura más voluminoso o más prematuro en las fracturas de hueso largo se ha buscado un modelo experimental en rata Wistar con y sin lesión encefálica. El estudio no demuestra diferencias significativas. Se discute la importancia de factores terapéuticos más que el hecho del traumatismo creaneoencefálico.Osteogenic response deviates significantly in patients with traumatic brain injury. In this study, we analyze if there is an increased volume or earlier callus formation in long bones fractures in Wistar rats with and without brain injury. The results show no significant difference. The importance of some therapeutical aspects other than head injury are discussed

Goat biodiversity in Spain

Goats are located predominantly in the dry Spain specially in Andalusia, Castilla-La Mancha, the Canary Islands, Murcia and Extremadura. In this paper we have analyzed 867 samples of 18 Spanish goat populations from different parts of the Iberian Peninsula (Azpi-Gorri, Blanca de Rasquera, Blanca Andaluza, Blanca Celtibérica, Florida, Malagueña, Murciano-Granadina, Negra Serrana, Payoya and Retinta) and the Balearic (Ibicenca, Mallorquina and Formentera goat) and Canarian Archipelagos (Ajuí, Majorera, Palmera, Tenerife North and Tenerife South). Twenty-three microsatellites have been amplified and the within-breed genetic variation has been calculated through the analysis of the mean number of alleles, heterozygosity and FIS The values of expected heterozygosity (He) per breed ranged from 0.524 to 0.721 in Palmera and Florida, respectively, while the observed heterozygosity (Ho) ranged between 0.515 and 0.705 in Palmera and Retinta, respectively. Goat genetic diversity in Spain is very high, with a mean number of alleles, expected and observed heterozigosities across the breeds of 7.04, 0.668 and 0.621, respectively.La especie caprina se localiza predominantemente en la España seca con gran protagonismo de Andalucía, Castilla-La Mancha, Canarias, Murcia y Extremadura. En este trabajo se analizan 867 muestras de 18 poblaciones caprinas españolas provenientes de diferentes zonas de la Península Ibérica (Azpi-Gorri, Blanca de Rasquera, Blanca Andaluza, Blanca Celtibérica, Florida, Malagueña, Murciano-Granadina, Negra Serrana, Payoya y Retinta) y de los archipiélagos Balear (Ibicenca, Mallorquina y cabra de Formentera) y Canario (Ajuí, Majorera, Palmera, Tinerfeña del Norte y Tinerfeña del Sur). Se amplifican 23 microsatélites de ADN y se determina la variación genética de las razas mediante el análisis del número medio de alelos, la heterocigosis, y el estadístico FIS. Los valores de heterocigosis esperada (He) oscilan entre 0,524 en la raza Palmera y 0,721 en la Florida mientras que la heterocigosis observada (Ho) fluctúa entre 0,515 en la Palmera y 0,705 en la Retinta. En España existe una diversidad genética caprina elevada con valores de número medio de alelos, heterocigosis esperada y observada para todas las razas de 7,04, 0,668 y 0,621 respectivamente