Predicción de la satisfacción y el rendimiento escolar: el compromiso como mediador

Introduction. Scholar academic results, both academic achievement and satisfaction with school, have been studied from different perspectives, given their implications in the design of educational policies. The aim of this study is to test two predictive structural models of academic achievement and school satisfaction. Method. These models pose school engagement as a mediator between the effects of Dominican students’ contextual and individual characteristics on the consequent academic results, in terms of school performance and satisfaction with school. In order to test these two models a sample of 1164 Dominican middle school students was used. The structural models were estimated in EQS 5.7. Results. Obtained results point out that school engagement is indeed an important mediator between the effects of contextual and personal variables at school and the academic results (achievement and satisfaction). Conclusion. These results may lead to reconsideration of school contexts where the quality of teaching, affective relationships between teachers and students and a socioemotional climate which favour mastery-oriented learning, take precedence. Thus, the results are discussed in relation to previous literature, limitations related to the cross-sectional nature of the study are highlighted, and future research directions suggested.Introducción. Los resultados académicos en la escuela, tanto el rendimiento como el sentimiento de satisfacción con ella, han sido estudiados desde diversas perspectivas, dadas sus implicaciones en el diseño de políticas educativas. El objetivo de este estudio es poner a prueba dos modelos estructurales predictivos, uno del rendimiento académico y el otro sobre la satisfacción con la escuela. Método. Estos modelos valoran importantes variables del contexto académico y posicionan el compromiso escolar del estudiante como un mediador de los efectos del contexto sobre las variables resultado. Para poner a prueba estos modelos se ha contado con una muestra de 1164 estudiantes de enseñanza media dominicanos. Los modelos estructurales se estimaron en EQS 5.7. Los resultados empíricos dan apoyo a ambos modelos predictivos; los productos obtenidos apuntan a que el compromiso escolar es un relevante intermediario de los efectos de las variables contextuales y del alumnado en sus logros académicos. Conclusiones. El fruto del trabajo da pie a concluir que hay que replantear el contexto escolar para primar la calidad de la instrucción, las relaciones afectivas entre los profesores y los alumnos, y un clima socioemocional que favorezca el aprendizaje orientado a la maestría. Así, se discuten los resultados obtenidos a la luz de la evidencia anterior y se sugieren también las limitaciones derivadas del carácter transversal del estudio así como las direcciones de cara a investigaciones futuras

Effect of goal-directed haemodynamic therapy on postoperative complications in low-moderate risk surgical patients: a multicentre randomised controlled trial (FEDORA trial)

Background The aim of this study was to evaluate postoperative complications in patients having major elective surgery using oesophageal Doppler monitor-guided goal-directed haemodynamic therapy (GDHT), in which administration of fluids, inotropes, and vasopressors was guided by stroke volume, mean arterial pressure, and cardiac index. Methods The FEDORA trial was a prospective, multicentre, randomised, parallel-group, controlled patient- and observer-blind trial conducted in adults scheduled for major elective surgery. Randomization and allocation were carried out by a central computer system. In the control group, intraoperative fluids were given based on traditional principles. In the GDHT group, the intraoperative goals were to maintain a maximal stroke volume, with mean arterial pressure >70 mm Hg, and cardiac index ≥2.5 litres min−1 m−2. The primary outcome was percentage of patients with moderate or severe postoperative complications during the first 180 days after surgery. Results In total, 450 patients were randomized to the GDHT group (n=224) or control group (n=226). Data from 420 subjects were analysed. There were significantly fewer with complications in the GDHT group (8.6% vs 16.6%, P=0.018). There were also fewer complications (acute kidney disease, pulmonary oedema, respiratory distress syndrome, wound infections, etc.), and length of hospital stay was shorter in the GDHT group. There was no significant difference in mortality between groups. Conclusions Oesophageal Doppler monitor-guided GDHT reduced postoperative complications and hospital length of stay in low–moderate risk patients undergoing intermediate risk surgery, with no difference in mortality at 180 days

Transmission of malaria and genotypic variability of Plasmodium falciparum on the Island of Annobon (Equatorial Guinea)

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Pregnancy in the mature adult mouse does not alter the proportion of mammary epithelial stem/progenitor cells

Introduction In humans, an early full-term pregnancy reduces lifetime breast cancer risk by up to 50% whereas a later pregnancy (>35 years old) can increase lifetime risk. Several mechanisms have been suggested, including changes in levels of circulating hormones, changes in the way the breast responds to these hormones, changes in gene expression programmes which may alter susceptibility to transformation and changes to mammary stem cell numbers or behaviour. Previous studies have shown that the mammary tissue isolated from both virgin and parous mice has the ability to repopulate a cleared mammary fat pad in transplant experiments. Limited dilution transplant assays have demonstrated that early pregnancy (at 5 weeks of age) reduces stem/progenitor cell numbers in the mouse mammary epithelium by twofold. However, the effects on stem/progenitor cell numbers in the mammary epithelium of a pregnancy in older animals have not yet been tested. Methods Mice were put through a full-term pregnancy at 9 weeks of age, when the mammary epithelium is mature. The total mammary epithelium was purified from parous 7-week post-lactation and age-matched virgin mice and analysed by flow cytometry and limiting dilution cleared fat pad transplants. Results There were no significant differences in the proportions of different mammary epithelial cell populations or numbers of CD24+/Low Sca-1- CD49fHigh cells (stem cell enriched basal mammary epithelial compartment). There was no significant difference in stem/progenitor cell frequency based on limiting dilution transplants between the parous and age-matched virgin epithelium. Conclusions Although differences between parous and virgin mammary epithelium at later time points post lactation or following multiple pregnancies cannot be ruled out, there are no differences in stem/progenitor cell numbers between mammary epithelium isolated from parous animals which were mated at 9 weeks old and virgin animals. However, a recent report has suggested that animals that were mated at 5 weeks old have a twofold reduction in stem/progenitor cell numbers. This is of interest given the association between early, but not late, pregnancy and breast cancer risk reduction in humans. However, a mechanistic connection between stem cell numbers and breast cancer risk remains to be established

Frequency, prognostic impact, and subtype association of 8p12, 8q24, 11q13, 12p13, 17q12, and 20q13 amplifications in breast cancers

BACKGROUND: Oncogene amplification and overexpression occur in tumor cells. Amplification status may provide diagnostic and prognostic information and may lead to new treatment strategies. Chromosomal regions 8p12, 8q24, 11q13, 17q12 and 20q13 are recurrently amplified in breast cancers. METHODS: To assess the frequencies and clinical impact of amplifications, we analyzed 547 invasive breast tumors organized in a tissue microarray (TMA) by fluorescence in situ hybridization (FISH) and calculated correlations with histoclinical features and prognosis. BAC probes were designed for: (i) two 8p12 subregions centered on RAB11FIP1 and FGFR1 loci, respectively; (ii) 11q13 region centered on CCND1; (iii) 12p13 region spanning NOL1; and (iv) three 20q13 subregions centered on MYBL2, ZNF217 and AURKA, respectively. Regions 8q24 and 17q12 were analyzed with MYC and ERBB2 commercial probes, respectively. RESULTS: We observed amplification of 8p12 (amplified at RAB11FIP1 and/or FGFR1) in 22.8%, 8q24 in 6.1%, 11q13 in 19.6%, 12p13 in 4.1%, 17q12 in 9.9%, 20q13(Z )(amplified at ZNF217 only) in 9.9%, and 20q13(Co )(co-amplification of two or three 20q13 loci) in 8.5% of cases. The 8q24, 12p13, and 17q12 amplifications were correlated with high grade. The most frequent single amplifications were 8p12 (9.8%), 8q24 (3.3%) and 12p13 (3.3%), 20q13(Z )and 20q13(Co )(1.6%) regions. The 17q12 and 11q13 regions were never found amplified alone. The most frequent co-amplification was 8p12/11q13. Amplifications of 8p12 and 17q12 were associated with poor outcome. Amplification of 12p13 was associated with basal molecular subtype. CONCLUSION: Our results establish the frequencies, prognostic impacts and subtype associations of various amplifications and co-amplifications in breast cancers

Osteoclasts control reactivation of dormant myeloma cells by remodelling the endosteal niche

Multiple myeloma is largely incurable, despite development of therapies that target myeloma cell-intrinsic pathways. Disease relapse is thought to originate from dormant myeloma cells, localized in specialized niches, which resist therapy and repopulate the tumour. However, little is known about the niche, and how it exerts cell-extrinsic control over myeloma cell dormancy and reactivation. In this study, we track individual myeloma cells by intravital imaging as they colonize the endosteal niche, enter a dormant state and subsequently become activated to form colonies. We demonstrate that dormancy is a reversible state that is switched ‘on’ by engagement with bone-lining cells or osteoblasts, and switched ‘off’ by osteoclasts remodelling the endosteal niche. Dormant myeloma cells are resistant to chemotherapy that targets dividing cells. The demonstration that the endosteal niche is pivotal in controlling myeloma cell dormancy highlights the potential for targeting cell-extrinsic mechanisms to overcome cell-intrinsic drug resistance and prevent disease relapse