Contexten en begripsontwikkeling bij wiskunde 12-16.

In this article the authors present some results of research into new curricula in secondary education constructed by the Foundation for Curriculum Development (SLO). One of the main characteristics of the new curricula is that mathematics is presented in real-life problems. The underlying concept is ‘Mathematics for All’. After being tested however, the low-achieving students seem to profit less from working with real-life problems than the more able students. However, this does not mean that the present authors would plead for throwing overboard real-life problems all together

Co-operative learning and adaptive instruction in a mathematics curriculum

The AGO 12 to 16 Project (the acronym AGO stands for the Dutch equivalent of 'Adaptive Instruction and Co-operative Learning') seeks to develop and evaluate a mathematics curriculum which is suitable for mixed-ability groups in secondary education. The research questions we will address here are, first, whether this curriculum is feasible and effective, and, second, what effects, if any, the context variables time and mean cognitive level of the class have on learning. Many mathematics programmes make insufficient allowance for the differences in intellectual ability that exist in mixed-ability classes. In order to change this situation we developed a mathematics curriculum with adaptive qualities. The evaluation of the experimental curriculum was carried out in two stages. During the first stage the curriculum was used at two schools with the aim of investigating the feasibility of the programme. Experience with the implementation of the programme led to some improvements in the experimental materials. By and large the AGO model appeared to be feasible in secondary classrooms. In the second stage, which was on a large scale, the focus was on the effectiveness of the programme. Six hundred students, 13 teachers and six schools were involved in the research. Teachers in the experimental group were trained in AGO methods and in implementing the new AGO curriculum. Teachers in the control groups worked with the existing programme following their usual methods of teaching. The main conclusion of the study is positive. The AGO model as a whole proved to be practical and effective in learning mathematics. The AGO model has a positive effect on the intercept, which means that the mean scores of AGO classes are higher than the mean scores of non-AGO classes. It may be concluded that, on the average, students benefit from learning in AGO classes as compared with non-AGO classes. AGO does not increase or decrease the differences between students in the same class. As expected, positive effects of two context variables were found: (1) the total amount of time spent in class covering the mathematical content and (2) class composition as indicated by the mean pretest score (aptitude) of the class

Gla Rich Protein (GRP) is associated to osteoarthritis being highly accumulated in the joint tissues and synovial fluid

info:eu-repo/semantics/publishedVersio

ER stress protein AGR2 precedes and is involved in the regulation of pancreatic cancer initiation

The work was supported by a grant A12008 from CR-UK (L. Dumartin, N.R. Lemoine and T. Crnogorac-Jurcevic)

Vitamin K supplementation increases vitamin K tissue levels but fails to counteract ectopic calcification in a mouse model for pseudoxanthoma elasticum

Pseudoxanthoma elasticum (PXE) is an autosomal recessive disorder in which calcification of connective tissue leads to pathology in skin, eye and blood vessels. PXE is caused by mutations in ABCC6. High expression of this transporter in the basolateral hepatocyte membrane suggests that it secretes an as-yet elusive factor into the circulation which prevents ectopic calcification. Utilizing our Abcc6−/− mouse model for PXE, we tested the hypothesis that this factor is vitamin K (precursor) (Borst et al. 2008, Cell Cycle). For 3 months, Abcc6−/− and wild-type mice were put on diets containing either the minimum dose of vitamin K required for normal blood coagulation or a dose that was 100 times higher. Vitamin K was supplied as menaquinone-7 (MK-7). Ectopic calcification was monitored in vivo by monthly micro-CT scans of the snout, as the PXE mouse model develops a characteristic connective tissue mineralization at the base of the whiskers. In addition, calcification of kidney arteries was measured by histology. Results show that supplemental MK-7 had no effect on ectopic calcification in Abcc6−/− mice. MK-7 supplementation increased vitamin K levels (in skin, heart and brain) in wild-type and in Abcc6−/− mice. Vitamin K tissue levels did not depend on Abcc6 genotype. In conclusion, dietary MK-7 supplementation increased vitamin K tissue levels in the PXE mouse model but failed to counteract ectopic calcification. Hence, we obtained no support for the hypothesis that Abcc6 transports vitamin K and that PXE can be cured by increasing tissue levels of vitamin K

Identification and manipulation of tumor associated macrophages in human cancers

Evading immune destruction and tumor promoting inflammation are important hallmarks in the development of cancer. Macrophages are present in most human tumors and are often associated with bad prognosis. Tumor associated macrophages come in many functional flavors ranging from what is known as classically activated macrophages (M1) associated with acute inflammation and T-cell immunity to immune suppressive macrophages (M2) associated with the promotion of tumor growth. The role of these functionally different myeloid cells is extensively studied in mice tumor models but dissimilarities in markers and receptors make the direct translation to human cancer difficult. This review focuses on recent reports discriminating the type of infiltrating macrophages in human tumors and the environmental cues present that steer their differentiation. Finally, immunotherapeutic approaches to interfere in this process are discussed

The evolution of mating systems in bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae)

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72492/1/j.1096-3642.1983.tb00858.x.pd

La coopération internationale en Afrique. Compte rendu des journées d'études tenues à Mogadiscio du 14 au 16 janvier 1960

Questo volume contiene gli atti del Convegno di Studi su "La cooperazione internazionale in Africa", che ha avuto luogo a Mogadiscio dal 14 al 16 gennaio 1960, in occasione dell'inaugurazione della sede dell'Istituto Universitario della Somalia.Buuggan waxaa ku urursan qoraalladii sherweynha daraasaadka ku saabsan "Iskaashiga Caalamiga ee Afrika" oo lagu qabtay Moqdisho 14-16 Jennayo 1960, munaasabada daahfurka Machadka Jaamacadda. Soomaaliya.This volume contains the proceedings of the Congress of Studies on "International cooperation in Africa"​​, which took place in Mogadishu on 14th-16th January 1960 on the occasion of the inauguration of the headquarters of the University of Somalia

Deciphering the Multifactorial Susceptibility of Mucosal Junction Cells to HPV Infection and Related Carcinogenesis

Human papillomavirus (HPV)-induced neoplasms have long been considered to originate from viral infection of the basal cell layer of the squamous mucosa. However, this paradigm has been recently undermined by accumulating data supporting the critical role of a discrete population of squamo-columnar (SC) junction cells in the pathogenesis of cervical (pre)cancers. The present review summarizes the current knowledge on junctional cells, discusses their high vulnerability to HPV infection, and stresses the potential clinical/translational value of the novel dualistic model of HPV-related carcinogenesis