Cloud computing and education: A state-of-the-art survey González-Martínez, José A.; Bote-Lorenzo, Miguel L.; Gómez-Sánchez, Eduardo ...
Computers and education,
January 2015, 2015-01-00, 20150101, Letnik:
80
Journal Article
Recenzirano
This paper surveys the state of the art on the use and research of cloud computing in education following a systematic methodology. After a comprehensive search of the scientific literature, 112 ...works were selected for the review. The survey identifies and analyzes the advantages and risks that the use of cloud computing may have for the main stakeholders in education, which can be useful to identify the scenarios in which the use of cloud computing in an educational context may have significant advantages. Furthermore, the survey categorizes and discusses the main technical and domain-specific research challenges, thus facilitating researchers the task of finding relevant issues, in which they can focus their efforts.
•We review 112 scientific works on cloud computing in education up to 2012.•The survey takes into account the main educational stakeholders.•Advantages and risks of cloud in education are categorized and exemplified.•We identify and discuss promising technical and domain-specific research issues.
Cell division requires the regulation of karyokinesis and cytokinesis, which includes an essential role of the achromatic spindle. Although the functions of centrosomes are well characterised in ...somatic cells, their role during vertebrate spermatogenesis remains elusive. We have studied the dynamics of the meiotic centrosomes in male mouse during both meiotic divisions. Results show that meiotic centrosomes duplicate twice: first duplication occurs in the leptotene/zygotene transition, while the second occurs in interkinesis. The maturation of duplicated centrosomes during the early stages of prophase I and II are followed by their separation and migration to opposite poles to form bipolar spindles I and II. The study of the genetic mouse model Plk1(Δ/Δ) indicates a central role of Polo‐like kinase 1 in pericentriolar matrix assembly, in centrosome maturation and migration, and in the formation of the bipolar spindles during spermatogenesis. In addition, in vitro inhibition of Polo‐like kinase 1 and Aurora A in organotypic cultures of seminiferous tubules points out to a prominent role of both kinases in the regulation of the formation of meiotic bipolar spindles.
Synopsis
Polo‐like Kinase 1 (PLK1) has a key role in the regulation of centrosome dynamics in male mouse meiosis. PLK1 participates in pericentriolar matrix (PCM) assembly, centrosome maturation and migration, and in the formation of the meiotic bipolar spindle.
Centrosomes duplicate twice during male mouse meiosis: in the leptotene/zygotene transition and during interkinesis.
Meiotic centrosomes separate during diplotene and during interkinesis/prophase II to facilitate the assembly of bipolar meiotic spindles.
Genetic ablation or chemical inhibition or PLK1 result in monopolar spindles in both meiotic divisions in mouse spermatocytes.
In vitro inhibition of PLK1 and AURKA suggest an important role of both kinases in formation of meiotic bipolar spindles.
Inhibition of PLK1 and AURKA impairs KIF11 localization to monopolar spindles.
Polo‐like Kinase 1 (PLK1) has a key role in the regulation of centrosome dynamics in male mouse meiosis. PLK1 participates in pericentriolar matrix (PCM) assembly, centrosome maturation and migration, and in the formation of the meiotic bipolar spindle.
Aims
To contrast functional connectivity on ventral and dorsal striatum networks in cocaine dependence relative to pathological gambling, via a resting‐state functional connectivity approach; and to ...determine the association between cocaine dependence‐related neuroadaptations indexed by functional connectivity and impulsivity, compulsivity and drug relapse.
Design
Cross‐sectional study of 20 individuals with cocaine dependence (CD), 19 individuals with pathological gambling (PG) and 21 healthy controls (HC), and a prospective cohort study of 20 CD followed‐up for 12 weeks to measure drug relapse.
Setting and Participants
CD and PG were recruited through consecutive admissions to a public clinic specialized in substance addiction treatment (Centro Provincial de Drogodependencias) and a public clinic specialized in gambling treatment (AGRAJER), respectively; HC were recruited through community advertisement in the same area in Granada (Spain).
Measurements
Seed‐based functional connectivity in the ventral striatum (ventral caudate and ventral putamen) and dorsal striatum (dorsal caudate and dorsal putamen), the Kirby delay‐discounting questionnaire, the reversal‐learning task and a dichotomous measure of cocaine relapse indicated with self‐report and urine tests.
Findings
CD relative to PG exhibit enhanced connectivity between the ventral caudate seed and subgenual anterior cingulate cortex, the ventral putamen seed and dorsomedial pre‐frontal cortex and the dorsal putamen seed and insula (P ≤ 0.001, kE = 108). Connectivity between the ventral caudate seed and subgenual anterior cingulate cortex is associated with steeper delay discounting (P ≤ 0.001, kE = 108) and cocaine relapse (P ≤ 0.005, kE = 34).
Conclusions
Cocaine dependence‐related neuroadaptations in the ventral striatum of the brain network are associated with increased impulsivity and higher rate of cocaine relapse.
Abstract Background The aim of this study was to compare the cognitive performance of cocaine dependent individuals (CDI) with that of pathological gamblers (PG). Cocaine dependence and pathological ...gambling share neurobiological vulnerabilities related to addiction, but PG are relatively free of the toxic consequences, such that any additional deficits observed in CDI may be interpreted as pertaining to specific drug effects. Methods We used a case–control observational design contrasting multiple measures of impulsivity (UPPS-P trait impulsivity, delay discounting) and executive measures of response inhibition (Stroop) and working memory performance ( N -back) between groups of CDI ( n = 29), PG ( n = 23), and healthy controls ( n = 20). We conducted one-way ANOVAs, followed by planned pairwise tests and calculations of Cohen's d to estimate significant differences between the groups. Results CDI, as compared to PG, had elevated scores on UPPS-P Negative Urgency and poorer performance on working memory (2-back). PG had steeper delay-discounting rates. Both groups had elevated Positive Urgency and poorer Stroop inhibition compared to controls. Peak amount of cocaine use was negatively correlated with working memory and response inhibition performance. Conclusion We found cocaine-related specific elevations in Negative Urgency and working memory deficits, putatively identified as cocaine neurotoxicity effects. Other aspects of impulsivity (Positive Urgency, Stroop inhibition) were increased across CDI and PG groups and may reflect vulnerability factors for addiction.
The impact of the mitochondria‐targeted antioxidant MitoQ was evaluated in the metabolic alterations and the adipose tissue remodeling associated with obesity. Male Wistar rats were fed either a ...high‐fat diet (HFD; 35% fat) or a standard diet (3.5% fat) for 7 wk and treated with MitoQ (200 μM). A proteomic analysis of visceral adipose tissue from patients with obesity and patients without obesity was performed. MitoQ partially prevented the increase in body weight, adiposity, homeostasis model assessment index, and adipose tissue remodeling in HFD rats. It also ameliorated protein level changes of factors involved in insulin signaling observed in adipose tissue of obese rats: reductions in adiponectin and glucose transporter 4 (GLUT 4) and increases in dipeptidylpeptidase 4, suppressor of cytokine signaling 3 (SOCS3), and insulin receptor substrate 1 phosphorylation. MitoQ prevented down‐regulation of adiponectin and GLUT 4 and increases in SOCS3 levels in a TNF‐α‐induced insulin‐resistant 3T3‐L1 adipocyte model. MitoQ also ameliorated alterations in mitochondrial proteins observed in obese rats: increases in cyclophylin F and carnitine palmitoyl transferase 1A and reductions in mitofusin1, peroxiredoxin 4, and fumarate hydratase. The proteomic analysis of the visceral adipose tissue from patients with obesity show alterations in mitochondrial proteins similar to those observed in obese rats. Therefore, the data show the beneficial effect of MitoQ in the metabolic dysfunction induced by obesity.—Marín‐Royo, G., Rodríguez, C., Le Pape, A., Jurado‐Lopez, R., Luaces, M., Antequera, A., Martinez‐Gonzalez, J., Souza‐Neto, F. V., Nieto, M. L., Martínez‐Martínez, E., Cachofeiro, V. The role of mitochondrial oxidative stress in the metabolic alterations in diet‐induced obesity in rats. FASEB J. 33, 12060‐12072 (2019). www.fasebj.org
Cocaine dependence frequently co‐occurs with personality disorders, leading to increased interpersonal problems and greater burden of disease. Personality disorders are characterised by patterns of ...thinking and feeling that divert from social expectations. However, the comorbidity between cocaine dependence and personality disorders has not been substantiated by measures of brain activation during social decision‐making. We applied functional magnetic resonance imaging to compare brain activations evoked by a social decision‐making task—the Ultimatum Game—in 24 cocaine dependents with personality disorders (CDPD), 19 cocaine dependents without comorbidities and 19 healthy controls. In the Ultimatum Game participants had to accept or reject bids made by another player to split monetary stakes. Offers varied in fairness (in fair offers the proposer shares ~50 percent of the money; in unfair offers the proposer shares <30 percent of the money), and participants were told that if they accept both players get the money, and if they reject both players lose it. We contrasted brain activations during unfair versus fair offers and accept versus reject choices. During evaluation of unfair offers CDPD displayed lower activation in the insula and the anterior cingulate cortex and higher activation in the lateral orbitofrontal cortex and superior frontal and temporal gyri. Frontal activations negatively correlated with emotion recognition. During rejection of offers CDPD displayed lower activation in the anterior cingulate cortex, striatum and midbrain. Dual diagnosis is linked to hypo‐activation of the insula and anterior cingulate cortex and hyper‐activation of frontal–temporal regions during social decision‐making, which associates with poorer emotion recognition.
Patients with cocaine dependence and personality disorders performing a social economic decision‐making task display reduced activation of the insula and the anterior cingulate cortex regions, which typically held the emotional aspects of social offers, and greater activation of frontal and temporal regions, which is negatively associated with emotion recognition skills.
Cocaine dependence is associated with pronounced elevations of negative affect and deficient regulation of negative emotions. We aimed to investigate the neural substrates of negative emotion ...regulation in cocaine‐dependent individuals (CDI), as compared to non‐drug‐using controls, using functional magnetic resonance imaging (fMRI) during a re‐appraisal task. Seventeen CDI abstinent for at least 15 days and without other psychiatric co‐morbidities and 18 intelligence quotient‐matched non‐drug‐using controls participated in the study. Participants performed the re‐appraisal task during fMRI scanning: they were exposed to 24 blocks of negative affective or neutral pictures that they should Observe (neutral pictures), Maintain (sustain the emotion elicited by negative pictures) or Suppress (regulate the emotion elicited by negative pictures through previously trained re‐appraisal techniques). Task‐related activations during two conditions of interest (Maintain>Observe and Suppress>Maintain) were analyzed using the general linear model in SPM8 software. We also performed psychophysiological interaction (PPI) seed‐based analyses based on one region from each condition: the dorsolateral prefrontal cortex (dlPFC—Maintain>Observe) and the inferior frontal gyrus (IFG—Suppress>Maintain). Results showed that cocaine users had increased right dlPFC and bilateral temporoparietal junction activations during Maintain>Observe, whereas they showed decreased right IFG, posterior cingulate cortex, insula and fusiform gyrus activations during Suppress>Maintain. PPI analyses showed that cocaine users had increased functional coupling between the dlPFC and emotion‐related regions during Maintain>Observe, whereas they showed decreased functional coupling between the right IFG and the amygdala during Suppress>Maintain. These findings indicate that CDI have dysfunctional corticolimbic activation and connectivity during negative emotion experience and re‐appraisal.
Using a cognitive reappraisal task during fMRI scanning we showed that cocaine dependent users display increased right dorsolateral prefrontal cortex (rDLPFC) activation while experiencing negative emotions, and decreased right inferior frontal gyrus (rIFG) activation while attempting to regulate these emotions. Connectivity analyses further showed that cocaine users exhibit increased connectivity between rDLPFC and regions involved in emotional appraisal during the experience of emotions, and decreased connectivity between the rIFG and the amygdala during the regulation of negative emotions.
Lysyl oxidase (LOX) proteins comprise a family of five copper-dependent enzymes (LOX and four LOX-like isoenzymes (LOXL1-4)) critical for extracellular matrix (ECM) homeostasis and remodeling. The ...primary role of LOX enzymes is to oxidize lysyl and hydroxylysyl residues from collagen and elastin chains into highly reactive aldehydes, which spontaneously react with surrounding amino groups and other aldehydes to form inter- and intra-catenary covalent cross-linkages. Therefore, they are essential for the synthesis of a mature ECM and assure matrix integrity. ECM modulates cellular phenotype and function, and strikingly influences the mechanical properties of tissues. This explains the critical role of these enzymes in tissue homeostasis, and in tissue repair and remodeling. Cardiac ECM is mainly composed of fibrillar collagens which form a complex network that provides structural and biochemical support to cardiac cells and regulates cell signaling pathways. It is now becoming apparent that cardiac performance is affected by the structure and composition of the ECM and that any disturbance of the ECM contributes to cardiac disease progression. This review article compiles the major findings on the contribution of the LOX family to the development and progression of myocardial disorders.
Vascular smooth muscle cells (VSMCs) transdifferentiate into osteoblast‐like cells during vascular cal‐cification, inducing active remodeling and calcification of the extracellular matrix (ECM). ...Intracellular and extracellular enzymes, such as lysyl hydroxylase 1 (PLOD1) and lysyl oxidase (LOX), contribute to ECM maturation and stabilization. We assessed the contribution of these enzymes to hyperphosphatemia‐induced calcification. Human and murine VSMCs were differentiated into functional osteoblast‐like cells by high‐phosphate medium (HPM) conditioning. HPM promoted ECM calcification and up‐regulated osteoblast markers associated with induction of LOX and PLOD1 expression and with an increase in ECM‐insoluble collagen deposition. Murine VSMCs from transgenic mice overexpressing LOX (TgLOX) exhibited an increase in HPM‐dependent calcification and osteoblast commitment compared with wild‐type cells. Similarly, enhanced HPM‐induced calcification was detected in aorta from TgLOX. Conversely, β‐aminopropionitrile (a LOX inhibitor) and LOX knockdown abrogated VSMC calcification and transdifferentiation. We found a significant positive association between LOX expression and vascular calcification in human atherosclerotic lesions. Likewise, 2, 2′‐dipyridil (a PLOD inhibitor) and PLOD1 knockdown impaired HPM‐induced ECM mineralization and osteoblast commitment. Our findings identify LOX and PLOD as critical players in vascular calcification and highlight the importance of ECM remodeling in this process.—Jover, E., Silvente, A., Marín, F., Martínez‐González, J., Orriols, M., Martinez, C. M., Puche, C. M., Valdés, M., Rodriguez, C., Hernaindez‐Romero, D. Inhibition of enzymes involved in collagen cross‐linking reduces vascular smooth muscle cell calcification. FASEB J. 32, 4459–4469 (2018). www.fasebj.org
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