The Skinny on Being Narrow: A Longitudinal Study on the Influence of Niche-Width in the Presence of Market Turbulence

This study examines whether product specialization offers retailers greater performance in a period of market turbulence. Incumbent retailers of home improvement products were followed over six years (1995-2001) comprising a period before, during, and after a period of environmental turbulence generated by the entry of large format retailers Home Depot and Revy to the Winnipeg market. Data collection involved survey, interview, and observational methods of 58 participants. Niche width was operationalized using four different methods, yet no significant difference could be found in the performance of organizations that specialized or generalized in home improvement products. This finding goes against much of the cross-sectional research on product specialization and niche strategies in retail, underscoring the importance of longitudinal study in research on organizations

Soil redistribution and carbon dynamics in Mediterranean agroecosystems: Radioisotopic modelling at different spatial and temporal scales

66 Pags. Tesis elaborada en la EEAD-CSIC y presentada en la Univ. Zaragoza, Departamento de Ciencias de la Tierra. Incluye las referencias de los ocho artículos científicos realizados durante el período de la tesis, accesibles a texto completo a través de sus enlaces doi (versiones de los editores) y handle (versiones finales de autor en acceso abierto depositadas en repositorio Digital.CSIC) .The results of this thesis revealed that the spatial patterns of soil properties and soil nutrients are closely related to landscape position and topographie characteristies. Higher contents of finer soíl particles «0.05 mm soil fractíon) including magnetic minerals and 137cs, soil organic matter and SOC and SON were reeorded in the upper part of the field. On the contrary the contents of carbonate, coarse and sand fractions were inversely corrrelated with topographic characteristics. Spatial patterns of soil properties, 137Cs and soil nutrients indicated that their distribution was related to similar physical processes.This thesis contributes lo improve the knowledge of mechanisms that can explain why soil characteristics, land use and redistribution processcs are key factors that determine the current status of soil and can be used to identify suitable locations for implementing soil conservation strategies in Mediterranean mountain agroecosyslems.This doctoral project was funded by a pre-doctoral fellowship (Formación de Personal Investigador; FPI BES-2009-016976) of the Spanish Ministry of Economy and Competitiveness associated with the lnterministerial Commission for Science and Technology (CICYT) projects "Soil erosion and carbon dynamics in Mediterranean agroecosystems: radioisotopic modelling at different spatial and temporal scales" (MEDEROCAR; CGL2008-0831) and "Erosion and redistribution of soils and nutrients in Mediterranean agroecosystems: radioisotopic tracers of sources and sinks and modelling scenarios" (EROMED; CGL2011-25486) of the Spanish Ministry of Economy and Competitiveness.Peer reviewe

Physical distress in children with learning difficulties

Thesis (M.S.)--Boston Universit

Methods for cleaning the BOLD fMRI signal

Available online 9 December 2016 http://www.sciencedirect.com/science/article/pii/S1053811916307418?via%3Dihubhttp://www.sciencedirect.com/science/article/pii/S1053811916307418?via%3DihubBlood oxygen-level-dependent functional magnetic resonance imaging (BOLD fMRI) has rapidly become a popular technique for the investigation of brain function in healthy individuals, patients as well as in animal studies. However, the BOLD signal arises from a complex mixture of neuronal, metabolic and vascular processes, being therefore an indirect measure of neuronal activity, which is further severely corrupted by multiple non-neuronal fluctuations of instrumental, physiological or subject-specific origin. This review aims to provide a comprehensive summary of existing methods for cleaning the BOLD fMRI signal. The description is given from a methodological point of view, focusing on the operation of the different techniques in addition to pointing out the advantages and limitations in their application. Since motion-related and physiological noise fluctuations are two of the main noise components of the signal, techniques targeting their removal are primarily addressed, including both data-driven approaches and using external recordings. Data-driven approaches, which are less specific in the assumed model and can simultaneously reduce multiple noise fluctuations, are mainly based on data decomposition techniques such as principal and independent component analysis. Importantly, the usefulness of strategies that benefit from the information available in the phase component of the signal, or in multiple signal echoes is also highlighted. The use of global signal regression for denoising is also addressed. Finally, practical recommendations regarding the optimization of the preprocessing pipeline for the purpose of denoising and future venues of research are indicated. Through the review, we summarize the importance of signal denoising as an essential step in the analysis pipeline of task-based and resting state fMRI studies.This work was supported by the Spanish Ministry of Economy and Competitiveness [Grant PSI 2013–42343 Neuroimagen Multimodal], the Severo Ochoa Programme for Centres/Units of Excellence in R & D [SEV-2015-490], and the research and writing of the paper were supported by the NIMH and NINDS Intramural Research Programs (ZICMH002888) of the NIH/HHS

Effect of prewhitening in resting-state functional near-infrared spectroscopy data

Published: 24 October 2018Near-infrared spectroscopy (NIRS) offers the potential to characterize resting-state functional connectivity (RSFC) in populations that are not easily assessed otherwise, such as young infants. In addition to the advantages of NIRS, one should also consider that the RS-NIRS signal requires specific data preprocessing and analysis. In particular, the RS-NIRS signal shows a colored frequency spectrum, which can be observed as temporal autocorrelation, thereby introducing spurious correlations. To address this issue, prewhitening of the RS-NIRS signal has been recently proposed as a necessary step to remove the signal temporal autocorrelation and therefore reduce false-discovery rates. However, the impact of this step on the analysis of experimental RS-NIRS data has not been thoroughly assessed prior to the present study. Here, the results of a standard preprocessing pipeline in a RS-NIRS dataset acquired in infants are compared with the results after incorporating two different prewhitening algorithms. Our results with a standard preprocessing replicated previous studies. Prewhitening altered RSFC patterns and disrupted the antiphase relationship between oxyhemoglobin and deoxyhemoglobin. We conclude that a better understanding of the effect of prewhitening on RS-NIRS data is still needed before directly considering its incorporation to the standard preprocessing pipeline.This research was possible due to the support of the Basque Government predoctoral grant PRE_2016_2_0188 to Borja Blanco, as well as the support of the Spanish Ministry of Economy and Competitiveness through the project PSI 2014-54512-P, Juan de la Cierva Fellowship (IJCI-2014-20821) and the “Severo Ochoa” Programme for Centres/Units of Excellence in R & D (SEV-2015-490)

Closing eyes during auditory memory retrieval modulates alpha rhythm but does not alter tau rhythm

Available online 20 April 2019The alpha power increase that occurs when the eyes are closed is one of the most well-known effects in human electrophysiology. In particular, previous psychological studies have investigated whether eye closure can boost memory performance under certain circumstances, providing contradictory evidence across sensory input modalities. Although alpha power is modulated during different phases of memory and these modulations are correlated with performance, few studies have reported on the relationship between eye closure, memory, and alpha-band power. The present study investigates the influence of eye closure while participants (n = 21) performed an auditory recognition memory task with spoken words during the recording of magnetoencephalography (MEG) data. Our results showed no evidence for a behavioural effect of eye closure in the performance of the task. In addition, electrophysiological responses to the stimuli showed the expected alpha event-related desynchronization (ERD) 0.5–1 s and a high-alpha/beta event-related synchronization (ERS) 1–2 s after word onset. The data showed the expected memory effect, i.e. remembered words elicited greater 10 Hz ERD than forgotten words in the brain regions typically associated with the language network, suggesting a modulation of tau rhythm. Eye closure modulated alpha rhythm only in posterior-parietal and occipital regions. The lack of interaction and the different localizations found for modulations of tau and classical alpha rhythms suggests that these rhythms play distinct functional roles in memory performance.This research was possible thanks to the support of the “Severo Ochoa Program for Centres/Units of Excellence in R&D” (SEV-2015-490). AB was supported by the Basque Government (Eusko Jaurlaritza) under the program “Ikertzaile ez doktoreen doktoretza-aurreko formakuntza programa” ( PRE_2015_2_0208), CCG was supported by the Spanish Ministry of Economy and Competitiveness through the Juan de la Cierva (IJCI- 2014-20821) and Ramon y Cajal (RYC-2017-21845) Fellowships

A LOW RANK AND SPARSE PARADIGM FREE MAPPING ALGORITHM FOR DECONVOLUTION OF FMRI DATA

Date Added to IEEE Xplore: 25 May 2021Current deconvolution algorithms for functional magnetic resonance imaging (fMRI) data are hindered by widespread signal changes arising from motion or physiological processes (e.g. deep breaths) that can be interpreted incorrectly as neuronal-related hemodynamic events. This work proposes a novel deconvolution approach that simultaneously estimates global signal fluctuations and neuronalrelated activity with no prior information about the timings of the blood oxygenation level-dependent (BOLD) events by means of a low rank plus sparse decomposition algorithm. The performance of the proposed method is evaluated on simulated and experimental fMRI data, and compared with state-of-the-art sparsity-based deconvolution approaches and with a conventional analysis that is aware of the temporal model of the neuronal-related activity. We demonstrate that the novel low-rank and sparse paradigm free mapping algorithm can estimate global signal fluctuations related to motion in our task, while estimating the neuronal-related activity with high fidelity

El vincle entre imaginació i llibertat a partir de Kant

Treballs Finals del Màster en Pensament Contemporani i Tradició Clàssica, Facultat de Filosofia, Universitat de Barcelona. Curs: 2019-2020. Tutor: Salvi Turró i TomàsEn aquest estudi volem indagar en aquest vincle entre la imaginació i la llibertat en l’ésser humà a partir del plantejament kantià del sistema de facultats, postulant una relació d’implicació mútua, de reciprocitat entre ambdues. La tesi que volem defensar sosté que no podríem imaginar si no hi hagués alguna sort de llibertat constitutiva en nosaltres i, alhora, no ens podríem concebre com a éssers lliures (i que actuen lliurement) si no tinguéssim la capacitat d’imaginar. En cap cas això implica que la imaginació sigui la facultat de la llibertat, sinó que la constitució d’una i altra es coimpliquen; altrament dit, la imaginació és intrínsecament lliure i la llibertat humana és connatural a la imaginació. Aquest vincle, conseqüentment, seria fonamental per a la comprensió de la naturalesa humana, ja que permetria pensar el nucli de tot allò que considerem pròpiament humà, sigui per oposició o extensió de la resta d’éssers vius

Cuartango, R. (2019). Posthistoria y transhumanidad. Madrid: Abada Editores.

Ressenya de Cuartango, R. (2019). Posthistoria y transhumanidad. Madrid: Abada Editores

Linking spatial patterns of soil redistribution traced with 137Cs and soil nutrients in a Mediterranean mountain agroecosystem (NE Spain)

1 Pag.This study aims to address soil movement and soil nutrient dynamics closely related to the status of soil degradation. A rain-fed cereal field (1.6 ha) representative of Mediterranean mountain agricultural landscapes (42 25’41”N 1 13’8”W) was selected to examine the effects of soil redistribution processes on the spatial variability of soil organic carbon (SOC) and nitrogen (SON) and their relationships with soil properties and topographic characteristics.Peer reviewe