K-means algorithms for functional data

Cluster analysis of functional data considers that the objects on which you want to perform a taxonomy are functions f : X e Rp ↦R and the available information about each object is a sample in a finite set of points f ¼ fðx ; y ÞA X x Rgn . The aim is to infer the meaningful groups by working explicitly with its infinite-dimensional nature. In this paper the use of K-means algorithms to solve this problem is analysed. A comparative study of three K-means algorithms has been conducted. The K-means algorithm for raw data, a kernel K-means algorithm for raw data and a K-means algorithm using two distances for functional data are tested. These distances, called dVn and dϕ, are based on projections onto Reproducing Kernel Hilbert Spaces (RKHS) and Tikhonov regularization theory. Although it is shown that both distances are equivalent, they lead to two different strategies to reduce the dimensionality of the data. In the case of dVn distance the most suitable strategy is Johnson–Lindenstrauss random projections. The dimensionality reduction for dϕ is based on spectral methods

Revisiting kernel logistic regression under the random utility models perspective. An interpretable machine-learning approach

The success of machine-learning methods is spreading their use to many different fields. This paper analyses one of these methods, the Kernel Logistic Regression (KLR), from the point of view of Random Utility Model (RUM) and proposes the use of the KLR to specify the utilities in RUM, freeing the modeller from the need to postulate a functional relation between the features. A Monte Carlo simulation study is conducted to empirically compare KLR with the Multinomial Logit (MNL) method, the Support Vector Machine (SVM) and the Random Forests (RF). We have shown that, using simulated data, KLR is the only method that achieves maximum accuracy and leads to an unbiased willingness-to-pay estimator for non-linear phenomena. In a real travel mode choice problem, RF achieved the highest predictive accuracy, followed by KLR. However, KLR allows for the calculation of indicators such as the value of time, which is of great importance in the context of transportation

A cephalometric method to diagnosis the craniovertebral junction abnormalities in osteogenesis imperfecta patients

Osteogenesis imperfecta (OI) is a hereditary bone fragility disorder that in most patients is caused by mutations affecting collagen type I. Their typical oral and craneofacial characteristics (Dentinogenesis imperfecta type I and class III malocclusion), involve the dentist in the multidisciplinary team that treat these patients. It is usual to perform lateral skull radiographs for the orthodontic diagnosis. In addition, this radiograph is useful to analyse the junctional area between skull base and spine, that could be damaged in OI. Pathology in the craneovertebral junction (CVJ) is a serious complication of OI with a prevalence ranging from rare to 37%. To diagnosis early skull base anomalies in these patients, previously the neurological symptoms have been appear, we make a simple cephalometric analysis of the CVJ. This method has four measurements and one angle. Once we calculate the values of the OI patient, we compare the result with the mean and the standard deviations of an age-appropriate average in healthy controls. If the patient has a result more than 2,5 SDs above the age- appropriate average in healthy controls, we should to refer the patient to his/her pediatrician or neurologist. These doctors have to consider acquiring another diagnostic images to be used to determine cranial base measurements with more reliability. Thereby, dentists who treat these patients, must be aware of the normal radiological anatomy of the cervical spine on the lateral cephalogram

Correlation between work impairment, scores of rhinitis severity and asthma using the MASK-air (R) App

Background In allergic rhinitis, a relevant outcome providing information on the effectiveness of interventions is needed. In MASK-air (Mobile Airways Sentinel Network), a visual analogue scale (VAS) for work is used as a relevant outcome. This study aimed to assess the performance of the work VAS work by comparing VAS work with other VAS measurements and symptom-medication scores obtained concurrently. Methods All consecutive MASK-air users in 23 countries from 1 June 2016 to 31 October 2018 were included (14 189 users; 205 904 days). Geolocalized users self-assessed daily symptom control using the touchscreen functionality on their smart phone to click on VAS scores (ranging from 0 to 100) for overall symptoms (global), nose, eyes, asthma and work. Two symptom-medication scores were used: the modified EAACI CSMS score and the MASK control score for rhinitis. To assess data quality, the intra-individual response variability (IRV) index was calculated. Results A strong correlation was observed between VAS work and other VAS. The highest levels for correlation with VAS work and variance explained in VAS work were found with VAS global, followed by VAS nose, eye and asthma. In comparison with VAS global, the mCSMS and MASK control score showed a lower correlation with VAS work. Results are unlikely to be explained by a low quality of data arising from repeated VAS measures. Conclusions VAS work correlates with other outcomes (VAS global, nose, eye and asthma) but less well with a symptom-medication score. VAS work should be considered as a potentially useful AR outcome in intervention studies.Peer reviewe

Primeras citas de Onychogomphus cazuma Barona, Cardo & Díaz, 2020 (Odonata: Anisoptera: Gomphidae) para la región de Castilla-La Mancha (centro-este de España)

The first data on the biology of Onychogomphus cazuma Barona, Cardo & Díaz, 2020 in Castilla-La Mancha region are provided. Its reproduction in this territory is confirmed by the detection of exuvians and a teneral female. The species had been only detected in the province of Valencia, in locations more than 100 km away.En el presente documento se aportan los primeros datos sobre la biología de Onychogomphus cazuma Barona, Cardo & Díaz, 2020 en la región de Castilla-La Mancha (centro-este de España), confirmando su reproducción en dicho territorio mediante el hallazgo de exuvias y una hembra recién emergida. Hasta la fecha la especie solo se había detectado en la provincia de Valencia, en localidades situadas a más de 100 km

A cephalometric method to diagnosis the craniovertebral junction abnormalities in osteogenesis imperfecta patients

Osteogenesis imperfecta (OI) is a hereditary bone fragility disorder that in most patients is caused by mutations affecting collagen type I. Their typical oral and craneofacial characteristics (Dentinogenesis imperfecta type I and class III malocclusion), involve the dentist in the multidisciplinary team that treat these patients. It is usual to perform lateral skull radiographs for the orthodontic diagnosis. In addition, this radiograph is useful to analyse the junctional area between skull base and spine, that could be damaged in OI. Pathology in the craneovertebral junction (CVJ) is a serious complication of OI with a prevalence ranging from rare to 37%. To diagnosis early skull base anomalies in these patients, previously the neurological symptoms have been appear, we make a simple cephalometric analysis of the CVJ. This method has four measurements and one angle. Once we calculate the values of the OI patient, we compare the result with the mean and the standard deviations of an age-appropriate average in healthy controls. If the patient has a result more than 2,5 SDs above the age appropriate average in healthy controls, we should to refer the patient to his/her pediatrician or neurologist. These doctors have to consider acquiring another diagnostic images to be used to determine cranial base measurements with more reliability. Thereby, dentists who treat these patients, must be aware of the normal radiological anatomy of the cervical spine on the lateral cephalogram.This work was supported by Grant No. AP123942013 from the Mutua Madrileña Foundation for Medical Research, MadridDepto. de Especialidades Clínicas OdontológicasFac. de OdontologíaTRUEpu

First records of Onychogomphus cazuma Barona, Cardo & Díaz, 2020 (Odonata: Gomphidae) for the Castilla-La Mancha region (Spain)

En el presente documento se aportan los primeros datos sobre la biología de Onychogomphus cazuma Barona, Cardo & Díaz, 2020 en la región de Castilla-La Mancha (centro-este de España), confirmando su reproducción en dicho territorio mediante el hallazgo de exuvias y una hembra recién emergida. Hasta la fecha la especie solo se había detectado en la provincia de Valencia, en localidades situadas a más de 100 kmFirst records of Onychogomphus cazuma Barona, Cardo & Díaz, 2020 (Odonata: Gomphidae) for the Castilla-La Mancha region (Spain) The first data on the biology of Onychogomphus cazuma Barona, Cardo & Díaz, 2020 in Castilla-La Mancha region are provided. Its reproduction in this territory is confirmed by the detection of exuvians and a teneral female. The species had been only detected in the province of Valencia, in locations more than 100 km away