Test item taxonomy based of functional criteria

There are many taxonomies that try to classify and apply some consistency to the very many item types currently in existence. They all have various limitations, however, such as ambiguous classification criteria, little discrimination between format types, and referring almost exclusively to pen-and-paper or screen-based items. This paper aims to overcome these limitations by proposing a new item format taxonomy based on functional criteria. Current classifications are reviewed, the criteria they are based on are examined and their limitations are identified. The proposed alternative classification identifies four essential components of items according to function: the structure of the included content, the device used for transmission of the question to the examinee, the device for receiving the response, and the instructions to the examinee about how to understand and respond to the item. The combination of different facets of these four components allows any format of item to be classified, both existing formats and those that may appear in the future. In addition to systematically and coherently classifying items, this new taxonomy may also be of great utility in the construction and research of new items. The proposed model is illustrated by examples showing how specific items are classified, using a checklist as a guide.Ministerio de Economía y Competitividad de España PSI2014-56114-PMinisterio de Economía y Competitividad de España PSI2017-85724-

Evaluación de aspectos docentes y materiales utilizados en la asignatura de Fundamentos Metodológicos en Psicología

Desde que empezó a impartirse en el curso 1994-95 en la asignatura de Fundamentos Metodológicos en Psicología se viene desarrollando una tarea sistemática con el objetivo de explicitar unos criterios comunes para la docencia, materiales y evaluación. En el presente trabajo se analizan las valoraciones que realizan los alumnos sobre distintos aspectos docentes de la citada asignatura, referidos al manual que por primera vez se ofrecía a los alumnos, así como a los materiales de prácticas y a la docencia impartida por cada profesor. Para ello se aplicó a los alumnos asistentes a prácticas en la última semana de clase una encuesta informatizada en la que debían valorar en una escala de 1 a 5 la adecuación de esos diversos aspectos docentes. En primer lugar los datos muestran una adecuada consistencia interna de las respuestas dadas al cuestionario. Con esa base los resultados muestran una valoración media favorable en todos los aspectos, aunque algo inferior a valoraciones encontradas en cursos anteriores. En todo caso, las valoraciones mejoran en aquellos alumnos que han cursado previamente la asignatura, estando algunas relacionadas con el profesor que la imparte y la motivación que procura

Validity of academic work indicators in the projected European Higher Education Area

The competencies achieved, the quantity and distribution of the time employed, and the activities carried out by the student are fundamental elements of the future European Higher Education Area. The present study explores, in a specific course, the current level of some indicators of such elements and their validity. The results highlight the irrelevance of the temporal aspects with respect to final performance, and the relevance of the academic work activities to performance over the length of the course. Each indicator is discussed, and it is intended to further those which result to be relevant for the success of the student in the future, and to limit those temporal elements to a mere function of organization of the universities

Idiosyncratic volatility, conditional liquidity and stock returns

There is strong evidence showing that stocks with higher levels of idiosyncratic risk provide relatively lower returns than stocks with lower levels of it. This paper points out that this negative idiosyncratic risk - expected returns relation is not pervasive over time, and provides a plausible explanation for its time-varying nature. Our results suggest that following recessions, the conditional pricing of liquidity, creates a correction in prices of the high idiosyncratic volatility stocks that persists up to 9 months. As a result, the negative relation between idiosyncratic risk and expected returns is not observed following recessions.Juliana Malagon acknowledges financial support from Universidad de Los Andes, Fondo de Apoyo para Profesores Asistentes [grant number P17.100322.004]. David Moreno acknowledges financial support from Ministerio de Ciencia y Tecnología [grant number ECO2013-42849-P]. Rosa Rodriguez acknowledges financial support from the Ministry of Economics and Competitiveness [grant number ECO2015-67035-P] and from Banco de España through the grant financing the research in macroceconomics, monetary economics finance and banking

Stem hydraulic capacitance decreases with drought stress : implications for modelling tree hydraulics in the Mediterranean oak Quercus ilex

Hydraulic modelling is a primary tool to predict plant performance in future drier scenarios. However, as most tree models are validated under non-stress conditions they may fail when water becomes limiting. To simulate tree hydraulic functioning under moist and dry conditions, the current version of a water flow and storage mechanistic model was further developed by implementing equations that describe variation in xylem hydraulic resistance (RX) and stem hydraulic capacitance (CS) with predawn water potential (ΨPD). The model was applied in a Mediterranean forest experiencing intense summer drought, where six Quercus ilex trees were instrumented to monitor stem diameter variations and sap flow, concurrently with measurements of predawn and midday leaf water potential. Best model performance was observed when CS was allowed to decrease with decreasing ΨPD. Hydraulic capacitance decreased from 62 to 25 kg m-3 MPa-1 across the growing season. In parallel, tree transpiration decreased to a greater extent than the capacitive water release and the contribution of stored water to transpiration increased from 2.0% to 5.1%. Our results demonstrate the importance of stored water and seasonality in CS for tree hydraulic functioning, and they suggest that CS should be considered to predict the drought-response of trees with models

Management sub-advising in the mutual fund industry

This is a study of how contractual mechanisms can mitigate agency conflicts in sub-advised mutual funds. Sub-advising contracts allow fund families to expand their product offerings to include new investment styles and thereby gain market share. We show that costly contractual arrangements, such as co-branding, multi-advising, and performance-based compensation, can mitigate agency conflicts in outsourcing and protect investors from potential underperformance. Fund families will find it cost-effective to implement such incentive mechanisms only when investors are sophisticated in assessing manager skill. The findings help to explain why a large percentage of fund families outsource their funds to advisory firms.Rafael Zambrana acknowledges financial support from the FCT Fundação para a Ciência e a Tecnologia under the project UID/ECO/00124/2013 and POR Lisboa (LISBOA-01-0145-FEDER-007722). David Moreno and Rosa Rodríguez thank financial support from Ministerio de Economía, Industria y Competitividad (through projects ECO2016- 77807-P and ECO2015-67035-P), WRDS-UC3M (FEDER UNCC315-EE-3636), CAM grant S2015/HUM-3353 (EARLYFIN-CM) and Bank of Spain (grant PR71/15-20229)

SUMOylation regulates LKB1 localization and its oncogenic activity in liver cancer

BACKGROUND: Even though liver kinase B1 (LKB1) is usually described as a tumor suppressor in a wide variety of tissues, it has been shown that LKB1 aberrant expression is associated with bad prognosis in Hepatocellular Carcinoma (HCC). METHODS: Herein we have overexpressed LKB1 in human hepatoma cells and by using histidine pull-down assay we have investigated the role of the hypoxia-related post-translational modification of Small Ubiquitin-related Modifier (SUMO)ylation in the regulation of LKB1 oncogenic role. Molecular modelling between LKB1 and its interactors, involved in regulation of LKB1 nucleocytoplasmic shuttling and LKB1 activity, was performed. Finally, high affinity SUMO binding entities-based technology were used to validate our findings in a pre-clinical mouse model and in clinical HCC. FINDINGS: We found that in human hepatoma cells under hypoxic stress, LKB1 overexpression increases cell viability and aggressiveness in association with changes in LKB1 cellular localization. Moreover, by using site-directed mutagenesis, we have shown that LKB1 is SUMOylated by SUMO-2 at Lys178 hampering LKB1 nucleocytoplasmic shuttling and fueling hepatoma cell growth. Molecular modelling of SUMO modified LKB1 further confirmed steric impedance between SUMOylated LKB1 and the STe20-Related ADaptor cofactor (STRADα), involved in LKB1 export from the nucleus. Finally, we provide evidence that endogenous LKB1 is modified by SUMO in pre-clinical mouse models of HCC and clinical HCC, where LKB1 SUMOylation is higher in fast growing tumors. INTERPRETATION: Overall, SUMO-2 modification of LKB1 at Lys178 mediates LKB1 cellular localization and its oncogenic role in liver cancer. FUND: This work was supported by grants from NIH (US Department of Health and Human services)-R01AR001576-11A1 (J.M.M and M.L.M-C.), Gobierno Vasco-Departamento de Salud 2013111114 (to M.L.M.-C), ELKARTEK 2016, Departamento de Industria del Gobierno Vasco (to M.L.M.-C), MINECO: SAF2017-87301-R and SAF2014-52097-R integrado en el Plan Estatal de Investigación Cientifica y Técnica y Innovación 2013-2016 cofinanciado con Fondos FEDER (to M.L.M.-C and J.M.M., respectively), BFU2015-71017/BMC MINECO/FEDER, EU (to A.D.Q. and I.D.M.), BIOEF (Basque Foundation for Innovation and Health Research): EITB Maratoia BIO15/CA/014; Instituto de Salud Carlos III:PIE14/00031, integrado en el Plan Estatal de Investigación Cientifica y Técnica y Innovacion 2013-2016 cofinanciado con Fondos FEDER (to M.L.M.-C and J.M.M), Asociación Española contra el Cáncer (T.C.D, P·F-T and M.L.M-C), Daniel Alagille award from EASL (to T.C.D), Fundación Científica de la Asociación Española Contra el Cancer (AECC Scientific Foundation) Rare Tumor Calls 2017 (to M.L.M and M.A), La Caixa Foundation Program (to M.L.M), Programma di Ricerca Regione-Università 2007-2009 and 2011-2012, Regione Emilia-Romagna (to E.V.), Ramón Areces Foundation and the Andalusian Government (BIO-198) (A.D.Q. and I.D.M.), ayudas para apoyar grupos de investigación del sistema Universitario Vasco IT971-16 (P.A.), MINECO:SAF2015-64352-R (P.A.), Institut National du Cancer, FRANCE, INCa grant PLBIO16-251 (M.S.R.), MINECO - BFU2016-76872-R to (E.B.). Work produced with the support of a 2017 Leonardo Grant for Researchers and Cultural Creators, BBVA Foundation (M.V-R). Finally, Ciberehd_ISCIII_MINECO is funded by the Instituto de Salud Carlos III. We thank MINECO for the Severo Ochoa Excellence Accreditation to CIC bioGUNE (SEV-2016-0644). Funding sources had no involvement in study design; in the collection, analysis, and interpretation of data; in the writing of the report; and in the decision to submit the paper for publication

Comparative Analysis of the Type III Secretion System Effector Repertoires of Pseudomonas savastanoi Pathovars Pathogenic on Woody Hosts

Comunicación de tipo pósterThe species Pseudomonas savastanoi, a member of the Pseudomonas syringae complex, includes four pathovars causing knots or excrescences in woody hosts: P. savastanoi pv. savastanoi (Psv), pv. fraxini (Psf), pv. nerii (Psn) and pv. retacarpa (Psr), comprising isolates from olive, ash, oleander and broom plants, respectively. Pathogenicity of P. savastanoi is dependent, among other factors, on the type III secretion system (T3SS) and its effector (T3E) repertoire. Furthermore, a putative role in the interaction with woody hosts has been suggested for several of these T3E. The recent availability of the genome sequences of several P. savastanoi strains isolated from different hosts has facilitated bioinformatics predictions of their T3SS genes and T3E pools, the study of their distribution in other strains of the P. syringae complex isolated from woody hosts and the functional analysis of several of these secreted proteins. As previously reported for Psv, Psn and Psf, here we show that pathogenicity of Psr ICMP16945, is also dependent on the T3SS. Psv strains NCPPB 3335, ICMP4352 and PseNe107 share a core set of at least 22 T3E, 18 of which are also encoded in Psn ICMP16943, Psf ICMP7711 and Psr ICMP16945. However, these three strains encode truncated versions of 1-2 of these 18 T3E and, Psr ICMP16945 contains three pathovarspecific T3E. Our results also show that several T3E, including HopAO1, are phylogenetically clustered across the P. syringae complex according to the woody/herbaceous nature of their host of isolation, suggesting host specialization of these effectors in this complex.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

New guidelines for developing multiple-choice items

The rigorous construction of items constitutes a field of great current interest for psychometric researchers and practitioners. In previous studies we had reviewed and analyzed the existing guidelines for the construction of multiple-choice items. From this review emerged a new proposal for guidelines that is now, in the present work, subjected to empirical assessment. This assessment was carried out by users of the guidelines and by experts in item construction. The results endorse the proposal for the new guidelines presented, confirming the advantages in relation to their simplicity and efficiency, as well as permitting identification of the difficulties involved in drawing up and organizing some of the guidelines. Taking into account these results, we propose a new, refined set of guidelines that constitutes a useful, simple and structured instrument for the construction of multiple-choice items