Francisco Javier Martin Vallejo

Francisco Javier Martin Vallejo
Universidad de Salamanca · Department of Statistics

PhD

About

89
Publications
12,666
Reads
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1,142
Citations
Introduction
Francisco Javier Martin Vallejo currently works at the Department of Statistics, Universidad de Salamanca. Francisco does research in data analysis, Statistics, Biostatistics, Meta-analysis, and Zoology.
Additional affiliations
January 1991 - present
Universidad de Salamanca
Position
  • Lecturer

Publications

Publications (89)
Article
Background: A surrogate classification of breast cancer (BC) molecular subtypes based on immunohistochemistry (IHC) was established at the 13th St. Gallen International Breast Cancer Consensus (SG-BCC). The most controversial point of discussion was the difference between the luminal A and B subtypes. The Ki-67 cut-off that has been used to differe...
Preprint
BACKGROUND The population of people over 65 years of age is currently growing thanks to social and health policies. This brings with it an increase in age-related diseases due to a series of morphological and physiological changes in these population groups. OBJECTIVE We aimed to study the effect of a physical exercise program on neurocognitive fu...
Article
Full-text available
During the normal aging process, a series of events occur, such as a decrease in telomere length and a decrease in various cognitive functions, such as attention, memory, or perceptual-motor speed. Several studies have attempted to establish a correlation between both variables; however, there is considerable controversy in the scientific literatur...
Article
Background: Determining predictive biomarkers for immune checkpoint inhibitors (ICIs) is a current challenge in oncology. Previous studies on non-small cell lung cancer (NSCLC) have shown how TP53 gene mutations are correlated with different responses to ICIs. Strong and diffuse immuno-expression of p53 by immunohistochemistry (IHC) is interpreted...
Article
Purpose Retinitis pigmentosa (RP) patients commonly experience negative psychological states due to their progressive and unpredictable loss of vision and visual variations related to stress. The aim of this study was to examine hair cortisol concentrations (HCCs), which is usually associated with chronic stress, pretending to unveil possible assoc...
Article
Background: Osteoporosis and obesity are major public health problems that are closely correlated, as they share various features, including a genetic predisposition. A genetic correlation between obesity and osteoporosis due to the biological common pathways of bone and fat metabolism, which implies pleiotropic genes regulating has been described...
Poster
Full-text available
OBJETIVO: Este estudo se propõe a determinar os fatores relacionados à doação de órgãos entre usuários brasileiros e equatorianos de redes sociais. MÉTODOS: Foi realizado um estudo transversal, avaliado por meio de um questionário autoadministrado e validado, distribuído nas redes sociais. RESULTADOS: Participaram desta pesquisa 408 indivíduos, 17,...
Article
Full-text available
Silicone oil (SO) still represents the main choice for long-term intraocular tamponade in complicated vitreoretinal surgery. This review compared the complications associated with the use of SO and other vitreous substitutes after pars plana vitrectomy in patients with different underlying diseases. Meta-analysis was conducted in accordance with PR...
Article
Full-text available
Background: Physical exercise is an effective measure for preventing the onset of cognitive decline and has a direct influence on the aging process. The purpose of this study was to assess the effect of a 6-month physical exercise program on cognition and telomere length in adults over 65 years of age. Method: Seventy-four healthy women were separa...
Article
The most widely accepted etiopathogenesis hypothesis of the origin of osteoporosis and its complications is that they are a consequence of bone aging and other environmental factors, together with a genetic predisposition. Evidence suggests that oxidative stress is crucial in bone pathologies associated with aging. The aim of this study was to dete...
Article
Objective: VA is currently considered the treatment of choice for patients with low and very low risk prostate cancer. We analyzed the evolution of this treatment strategy in our series and adherence to the protocol. Material and methods: Ambispective study of patients in VA in our center between 2014- 2019. 237 meet inclusion criteria, of which...
Article
Objetivo. El objetivo principal de nuestro estudio fue evaluar la utilidad actual del índice de comorbilidad de Charlson (CCI) para predecir la mortalidad en personas mayores y la concordancia entre varios índices. Diseño. Estudio observacional, cohorte concurrente. Emplazamiento. Servicio de Medicina Interna de un hospital terciario, pacientes amb...
Conference Paper
Full-text available
Countries have reported that people's attitudes towards organ donation are influenced by knowledge, education and religion. In Ecuador, more than 800 patients are on the waiting list for an organ; likewise, the population does not recognize the importance of the donation. Although, since 2011, the Organic Law of Donation and Transplantation of Orga...
Article
The aim of our research is to analyze how different religions influence business ethics. We develop an index of practices in the field of business ethics, made up of 19 items containing practices related to workers, consumers, products, human rights, management of ethical conflicts, and crime prevention. Also, we consider a wide range of religion a...
Article
Osteoporosis is the most common bone disorder worldwide and is associated with a reduced quality of life with important clinical and economic consequences. The most widely accepted etiopathogenic hypothesis on the origin of osteoporosis and its complications is that they are a consequence of the synergic action of environmental and genetic factors....
Article
The aetiology of essential hypertension is complex and involves both environmental and genetic factors. Approximately 30% of the inter-individual variability in blood pressure is genetically determined. It has been shown that numerous vasoconstrictors stimulate RhoA in local populations of vascular SMCs that, in turn, promote localised constriction...
Article
Full-text available
Several studies have stated that people's attitudes towards organ donation are influenced by factors such as knowledge, education, and religion. Many people could donate if they knew about the benefits of organ donation instead of wasting it. That is the reason that this study sets out to determine the knowledge, attitudes, and beliefs toward organ...
Article
The overall objective of this study was to examine the impact of a cognitive stimulation intervention model on subjects with mild-moderate Alzheimer’s disease (AD) using a comprehensive neuropsychological assessment. The stimulation intervention consisted of carrying out cognitive activities with a small group of participants during a 6-month perio...
Article
Objective: Dulaglutide is an agonist of "glucagon-like peptide type 1" receptors (arGLP1). The clinical efficacy of this molecule is based on reductions in glycosylated hemoglobin (HbA1c) and weight and the number of hypoglycemia, data shown in the pivotal AWARD studies. Methods: We propose a retrospective and multicenter study that allows evalu...
Article
This study aimed to assess how packaging imagery used to convey that a natural yogurt is sweetened influences consumer expectations and willingness to buy. Four packages of sweetened natural yogurt were designed, in which the message that they were sweetened was conveyed through three different images (sugar cubes, a sack of sugar and a spoon of su...
Article
The thermal ecology of ectotherms has been studied for almost two centuries, but additional attention is currently being paid to the issue in order to understand how organisms deal with the environment in a climate change context. However, a consensus is still far away, due to the large number of factors involved and their complex interactions. In...
Article
Due to the limited sample size and the heterogeneous nature of the data, we preferred to be conservative, only trusting the results from the first partitions of both meta-analyses (see the main text of this study). However, we provide here the full meta-analyses, in order to increase the transparency of our study and also because these results can...
Article
Full-text available
Multiple-trait experiments with mixed phenotypes (binary, ordinal and continuous) are not rare in animal and plant breeding programs. However, there is a lack of statistical models that can exploit the correlation between traits with mixed phenotypes in order to improve prediction accuracy in the context of genomic selection (GS). For this reason,...
Article
Background and aims: Heterozygous familial hypercholesterolemia (FH) is a genetic disorder characterized by high levels of low-density lipoprotein cholesterol (LDL-C). The magnitude of atherosclerotic cardiovascular disease (ASCVD) risk in FH patients is highly variable, and this can result from genetic factors. The aim of our study was to charact...
Article
Full-text available
Antidepressant-related sexual dysfunction is a frequent adverse event caused by serotonergic activation that intensely affects quality of life and adherence in depressed patients. The dopamine system has multiple effects promoting sexual behavior, but no studies have been carried out to confirm dopaminergic changes involved in animal models after a...
Article
Los indicadores utilizados habitualmente en materia de seguridad laboral hacen referencia generalmente a accidentes ocurridos, son indicadores retrasados, por cuanto las medidas que de ellos se pueden derivar ya no evitan el accidente que ha tenido lugar. Este artículo presenta una herramienta basada en la utilización de indicadores adelantados que...
Article
Full-text available
Genomic selection is revolutionizing plant breeding. However, still lacking are better statistical models for ordinal phenotypes to improve the accuracy of the selection of candidate genotypes. For this reason, in this paper we explore the genomic based prediction performance of two popular machine learning methods: the Multi Layer Perceptron (MLP)...
Article
Full-text available
Multi-trait and multi-environment data are common in animal and plant breeding programs. However, what is lacking are more powerful statistical models that can exploit the correlation between traits to improve prediction accuracy in the context of genomic selection (GS). Multi-trait models are more complex than univariate models and usually require...
Article
The packaging of a product is a key element in the communication between producers and consumers, so getting the consumer to interpret the packaging visual signs in the desired way is crucial to be successful in the marketplace. However, this is not easy as images can be ambiguous and may be interpreted in different ways. For example, depicting an...
Article
Many food packages on the market show an image of the product contained inside or the ingredients with which the product was produced. During the packaging design process, it is the job of the designer or the marketing team to decide which specific image will be depicted on the packaging. This paper analyses the potential implications of this decis...
Article
Background Cutaneous squamous cell carcinoma (cSCC) represents the most common form of skin cancer after basal cell carcinoma, and can be both locally invasive and metastatic to distant sites. Growth rate (GR) has been poorly evaluated in cSCC, despite clinical evidence suggesting that GR is an important risk factor in cSCC. Aim To analyse the inf...
Article
Objetivo principal: Determinar la utilización de la estadística en los artículos originales de la revista Index de Enfermería. Metodología: Estudio observacional descriptivo de los artículos publicados desde el 2010 hasta septiembre del 2015. Se recogieron las siguientes variables: Nº de artículos originales, nacionalidad, tipo de estudio y nivel d...
Poster
We presented meta-partition, a meta-analysis methodology for splitting heterogeneity of effect sizes by potential predictors. We analysed the data on the thermal ecology of the Lacertidae through meta-partition, which allowed us to assess the relative importance of the different proposed factors, as well as their interactions, driving the thermal e...
Article
Background: The classic version of the Wisconsin Card Sorting Test (WCST) consists of correctly sorting 128 cards according to changing sorting criteria. Its application is costly in terms of the time employed, with all the negative consequences this entails (decrease in motivation, frustration, and fatigue). Method: The main objective of this s...
Article
Can shrubs (Cytisus multiflorus) and large herbivore exclusion (fence) facilitate seedling survival and growth of marcescent and sclerophyllous oaks (Quercus pyrenaica vs Q. ilex subsp. ballota) under a bioclimatic limit in Mediterranean grazed areas? Open oak woodlands in central-western Spain (41º13’ N, 6º24’ W). A two-year field experiment was c...
Article
This paper analyses the influence of the illuminance level of a light source on how consumers evaluated certain attributes of sweetened natural yoghurt and on their willingness to buy during product tasting. It also seeks to identify whether or not gender differences played a role in these evaluations. To do this, we conducted an independent within...
Article
This paper analyses the influence that certain aspects of packaging design have on the consumer expectations of a series of sensory and non-sensory attributes and on willingness to buy for a bag of crisps in Spain. A two-part experiment was conducted in which 174 people evaluated the attributes for different stimuli using an online survey. In the f...
Chapter
Packaging design is a decisive factor in the perception that users have of a product before its consumption, so it is key to know precisely which design is the most suitable for the message that brands wish to convey. This research aims to study the influence of two variables, serving suggestion and label colour, on users’ perception of products wh...
Conference Paper
Full-text available
Traditionally, the shrub was considered as a harmful element for the restoration of plant species, but recent studies showed the facilitating role of shrub in Mediterranean forest restoration. Nevertheless, the effects generated can vary depending on the environment and shrub species involved. In this study, we evaluated if shrubs (Cytisus multiflo...
Article
Full-text available
The study of the heterogeneity of effect sizes is a key aspect of ecological meta-analyses. Here we propose a meta-analytic methodology to study the influence of moderators in effect sizes by splitting heterogeneity: meta-partition. To introduce this methodology, we performed a meta-partition of published data about the traits that influence specie...
Data
It comprises the detailed trees of the meta-partition, with comments about the intensity and direction of the effect of each moderator, and a table with all statistics obtained for each partition (QH, I2, and the integrated effect size), as well as the species that are included in each subset.
Data
Extended results of the meta-partition about the sensitivity of vertebrates to wetland habitat loss. It comprises the detailed trees of the meta-partition, with comments about the intensity and direction of the effect of each moderator, and a table with all statistics obtained for each partition (QH, I2, and the integrated effect size), as well as...
Article
Full-text available
Background: Cultural and social factors play an important role in the development and persistence of Low Back Pain (LBP). Nevertheless, there are few studies investigating differences in LBP features between countries. Objective: To determine differences in pain perception between individuals with LBP living in Brazil and Spain. Method: Thirty...
Article
This paper studies the influence that serving suggestions on a popular Spanish soft cheese - known as "queso fresco"-packaging have on consumer expectations regarding certain attributes of the product, its ideal consumption time during the day and the consumer's willingness to buy. Some 247 people participated in this investigation, evaluating 8 at...
Article
Background: Clinicians should be able to weigh the role of the main risk factors associated with early implant failure. Purpose: The aim of this meta-analysis was to assess the influence of different patient-related and implant-related risk factors on the occurrence of early implant failure. Materials and methods: In July, 2014 the main electr...
Article
Full-text available
This article examines the individual and contextual factors affecting peripheral identifications in Spain. It does so by conducting multilevel statistical analyses on two surveys on regional and national identifications that were carried out by the Centro de Investigaciones Sociológicas in 1996 and 2006, at two very different political conjunctures...
Article
This paper aims at identifying patterns of viewing chocolate snack packages and at exploring how the layout of packaging design elements affects the prospective buyer’s visual scanpath in impulse buying. For this purpose, different chocolate snack packages were designed and research participants viewed these for 1.5 s. After analysing the data obta...
Article
An important application of microarray technology is the assignment of new subjects to known clinical groups (class prediction), but the huge number of screened genes and the small number of samples make this task difficult. To overcome this problem, the usual approach has been to extract a small subset of significant genes (gene selection) or to u...
Article
Full-text available
La calidad de vida (CV) se define como la percepción personal que un individuo tiene de su situación vital. Dentro de los factores que pueden influir en la CV, se encuentra la Reserva Cognitiva (RC), que podría entenderse como la capacidad del cerebro para hacer frente al daño cerebral generado por la patología, mediante procesos cognitivos preexis...
Article
Full-text available
Malignant astrocytomas are the most common primary brain tumors and one of the most lethal among human cancers despite optimal treatment. Therefore, the characterization of molecular alterations underlying the aggressive behavior of these tumors and the identification of new markers are thus an important step towards a better patient stratification...
Article
Full-text available
Malignant astrocytomas are the most aggressive primary brain tumors with a poor prognosis despite optimal treatment. Dysfunction of mismatch repair (MMR) system accelerates the accumulation of mutations throughout the genome causing uncontrolled cell growth. The aim of this study was to characterize the MMR system defects that could be involved in...
Article
Meta-analysis integrates information from different studies to generate a common response to a determined problem. In the literature, we find several integration methods of results, with the integration method of levels of probability being the more basic and, with a greater complexity, the integration method of the effect size, which uses fixed an...
Article
Full-text available
Un meta-análisis integra información proveniente de varios estudios con el propósito de generar un resultado común para un problema determinado. En la literatura nos encontramos con varios métodos de integración de resultados, siendo el más básico el método de integración de niveles de probabilidad y, con una complejidad mayor, el método de integra...
Article
Full-text available
Meta-analysis integrates information from different studies to generate a common response to a determined problem. In the literature, we find several integration methods of results, with the integration method of levels of probability being the more basic and, with a greater complexity, the integration method of the effect size, which uses fixed an...
Article
This paper studies the influence of two design variables of chewing gum packaging, those of colour and format, on consumer expectations of specific product attributes and willingness to buy. Some 390 consumers participated in this investigation, evaluating a total of 30 functional, sensory and experience attributes for nine different packaging desi...
Article
Full-text available
Un meta-análisis integra información proveniente de varios estudios con el propósito de generar un resultado común para un problema determinado. En la literatura nos encontramos con varios métodos de integración de resultados, siendo el más básico el método de integración de niveles de probabilidad y, con una complejidad mayor, el método de integra...
Article
Some authors suggest that besides the fundamental components, cognitive reserve (CR) also reflects the influence of a combination of factors that improve mental health. After obtaining the sociodemographic profile of each participant and evaluating their neurologic and neuropsychologic abilities, first, homogeneity analysis was used as a technique...
Article
Cognitive reserve is an active mechanism based on the application of resources learned thanks to a good education, profession, or premorbid intelligence. The aim of this research is to study whether the inclusion of sociodemographic variables linked to lifestyle can discriminate individuals more effectively regarding their level of cognitive reserv...
Article
The aim of this study was to check the degree of consistency and agreement between three methods for the estimation of body composition, fat mass and fat-free mass after their application to a group of young women. A transverse observation study was performed. Fifty-nine women aged between 18 and 28 years old were included. Each woman was subjected...
Article
With the proliferation of related microarray studies by independent groups, a natural approach to analysis would be to combine the results across studies. In this article, we address a meta-analysis of the gene expression data on imatinib resistance in chronic myelogenous leukemia. First, an analysis of the overlapping among 6 published studies rev...
Article
A randomized controlled trial. To investigate the immediate effects on pressure pain thresholds over latent trigger points (TrPs) in the masseter and temporalis muscles and active mouth opening following atlanto-occipital joint thrust manipulation or a soft tissue manual intervention targeted to the suboccipital muscles. Previous studies have descr...
Article
The purpose of this study was to determine if the posterior-anterior cervical gliding test is a valid test as compared with dynamic radiographic assessment in flexion/extension as tool for the manual diagnosis of intervertebral joint hypomobility in the midcervical spine in patients with mechanical neck pain. The study was done according to Standar...
Article
Introduction There is a need to validate and coherently confirm clinical tests for the diagnosis of intervertebral joint dysfunctions. In the spine, restriction of intervertebral mobility may lead to a temporary reduction of postero-anterior vertebral gliding, which is diagnosed by means of physical examination. Objective To validate the postero-a...
Article
The purpose of this study was to investigate the immediate effects of bilateral talocrural joint manipulation on standing stability in healthy subjects. Sixty-two healthy subjects, 16 males and 46 females, aged from 18 to 32 years old (mean: 21+/-3 years old) participated in the study. Subjects were randomly divided into two groups: an intervention...
Article
There is general consensus that a successful endoscopic third ventriculostomy is usually followed by a decrease of ventricular size without reaching their normal size. This study was performed to determine how the change related to clinical outcome, how it developed chronologically and whether the change in ventricular size was different in acute a...
Article
Full-text available
The Balearic lizard, Podarcis lilfordi, is present in 43 insular populations in the Cabrera archipelago and around the coasts of Mallorca and Menorca islands (Spain). We studied lizard densities over the entire range of distribution, analyzing observed differences of density in relation to island area, habitat diversity, availability of resources,...